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• Cisco VPN Client Behind ASA 5505

  - by fdf33

  I'm trying to get connected to another ASA via Cisco VPN Client. I am behind an ASA 5505 myself and I am tryihng to VPN to a 5510. I get the message: Secure VPN Connection terminated locally by the Client. Reason 412: The remote peer is no longer responding. I can connect to the other ASA if I use a normal cheap Linksys. Here's the version of my ASA: Result of the command: "sh ver" Cisco Adaptive Security Appliance Software Version 8.4(1) Any help would be great. Thanks running-config : Saved : Written by enable_15 at 23:12:32.378 UTC Fri Jul 1 2011 ! ASA Version 8.4(1) ! hostname aaaasa domain-name aaa.local enable password xxxxxxxxxxxxxxx encrypted passwd xxxxxxxxxxxxxxxxxxxx encrypted names ! interface Vlan1 nameif inside security-level 100 ip address 192.168.1.254 255.255.255.0 ! interface Vlan2 nameif outside security-level 0 ip address xxx.xxx.xxx.xxx 255.255.254.0 ! interface Vlan5 no nameif security-level 50 ip address 172.16.0.254 255.255.255.0 ! interface Vlan500 no nameif security-level 100 ip address 10.10.10.1 255.255.255.0 ! interface Ethernet0/0 switchport access vlan 2 ! interface Ethernet0/1 ! interface Ethernet0/2 ! interface Ethernet0/3 ! interface Ethernet0/4 ! interface Ethernet0/5 ! interface Ethernet0/6 ! interface Ethernet0/7 ! boot system disk0:/asa841-k8.bin ftp mode passive dns domain-lookup inside dns domain-lookup outside dns server-group DefaultDNS name-server 4.2.2.2 domain-name aaa.local same-security-traffic permit inter-interface same-security-traffic permit intra-interface object network obj_any subnet 0.0.0.0 0.0.0.0 object network A_93.97.168.1 host 93.97.168.1 object network rdp host 192.168.1.2 object network NETWORK_OBJ_192.168.1.0_24 subnet 192.168.1.0 255.255.255.0 access-list 101 extended permit tcp any host 192.168.1.2 eq 3389 access-list 101 extended permit icmp any any echo-reply access-list 101 extended permit icmp any any source-quench access-list 101 extended permit icmp any any time-exceeded access-list 101 extended permit icmp any any unreachable access-list 102 extended permit ip any any pager lines 24 logging enable logging asdm informational mtu inside 1500 mtu outside 1492 ip local pool VPNPool 192.168.2.200-192.168.2.210 mask 255.255.255.0 icmp unreachable rate-limit 1 burst-size 1 asdm image disk0:/asdm-641.bin no asdm history enable arp timeout 14400 ! object network rdp nat (inside,outside) static interface service tcp 3389 3389 ! nat (inside,outside) after-auto source dynamic any interface access-group 101 in interface outside access-group 102 out interface outside ! router ospf 1 network 192.168.1.0 255.255.255.0 area 0 log-adj-changes ! route outside 0.0.0.0 0.0.0.0 93.97.168.1 1 timeout xlate 3:00:00 timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02 timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00 timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00 timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute timeout tcp-proxy-reassembly 0:01:00 dynamic-access-policy-record DfltAccessPolicy http server enable http 192.168.1.0 255.255.255.0 inside no snmp-server location no snmp-server contact snmp-server enable traps snmp authentication linkup linkdown coldstart crypto ipsec ikev2 ipsec-proposal DES protocol esp encryption des protocol esp integrity sha-1 md5 crypto ipsec ikev2 ipsec-proposal 3DES protocol esp encryption 3des protocol esp integrity sha-1 md5 crypto ipsec ikev2 ipsec-proposal AES protocol esp encryption aes protocol esp integrity sha-1 md5 crypto ipsec ikev2 ipsec-proposal AES192 protocol esp encryption aes-192 protocol esp integrity sha-1 md5 crypto ipsec ikev2 ipsec-proposal AES256 protocol esp encryption aes-256 protocol esp integrity sha-1 md5 crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set ikev2 ipsec-proposal AES256 AES192 AES 3DES DES crypto map outside_map 65535 ipsec-isakmp dynamic SYSTEM_DEFAULT_CRYPTO_MAP crypto map outside_map interface outside crypto ca trustpoint ASDM_TrustPoint0 enrollment self subject-name CN=ciscoasa proxy-ldc-issuer crl configure crypto ca certificate chain ASDM_TrustPoint0 certificate 8877d64d 30820248 308201b1 a0030201 02020488 77d64d30 0d06092a 864886f7 0d010105 05003036 3111300f 06035504 03130863 6973636f 61736131 21301f06 092a8648 86f70d01 09021612 63697363 6f617361 2e6e6a64 2e6c6f63 616c301e 170d3131 30353231 30383533 34325a17 0d323130 35313830 38353334 325a3036 3111300f 06035504 03130863 6973636f 61736131 21301f06 092a8648 86f70d01 09021612 63697363 6f617361 2e6e6a64 2e6c6f63 616c3081 9f300d06 092a8648 86f70d01 01010500 03818d00 30818902 818100ea 1aa95141 480e616c efee6816 a96d6511 313b6776 cd3dd57b cd84b4d2 5e108aee 7c980086 4d92e2eb b6c7bf66 4585af0a ccbf153a db9270be c6f5c67b db9dd8d1 2f78d033 3348b056 df4be0da 70e08953 53adf294 9db6c020 597d250f bf448b43 b90179c8 ff0b15d8 744632d9 31c1945f 0b11e258 b4c1d224 692efff4 7b2f5102 03010001 a3633061 300f0603 551d1301 01ff0405 30030101 ff300e06 03551d0f 0101ff04 04030201 86301f06 03551d23 04183016 8014493c 19db183a ab1af9e9 b1e44ad4 2a408b3c 89d1301d 0603551d 0e041604 14493c19 db183aab 1af9e9b1 e44ad42a 408b3c89 d1300d06 092a8648 86f70d01 01050500 03818100 1dd1760a fdd15941 4803fb9a cd6f44a7 2e275854 a1c0fbe1 d19f2cc9 182d43ef a547f854 8df96d15 3ea79c62 cf3fcb1c 5820360b c607dbfc 4de8bb16 19f727e9 b928a085 665816d8 138e4a35 ed610950 7910dd4a 0b1a9dd9 0e26f1c8 b78bc0cc cbf19eb2 4c4c3931 45199ea5 249e3266 661e44fd 7a00d376 dcfc6e4e d43f10b8 quit crypto isakmp nat-traversal 30 crypto ikev2 policy 1 encryption aes-256 integrity sha group 5 prf sha lifetime seconds 86400 crypto ikev2 policy 10 encryption aes-192 integrity sha group 5 prf sha lifetime seconds 86400 crypto ikev2 policy 20 encryption aes integrity sha group 5 prf sha lifetime seconds 86400 crypto ikev2 policy 30 encryption 3des integrity sha group 5 prf sha lifetime seconds 86400 crypto ikev2 policy 40 encryption des integrity sha group 5 prf sha lifetime seconds 86400 crypto ikev2 enable outside client-services port 443 crypto ikev2 remote-access trustpoint ASDM_TrustPoint0 telnet timeout 5 ssh 192.168.1.0 255.255.255.0 inside ssh timeout 5 console timeout 0 dhcpd auto_config outside ! dhcpd address 192.168.1.5-192.168.1.36 inside dhcpd dns 4.2.2.2 interface inside dhcpd enable inside ! threat-detection basic-threat threat-detection statistics host number-of-rate 3 threat-detection statistics port threat-detection statistics protocol threat-detection statistics access-list threat-detection statistics tcp-intercept rate-interval 30 burst-rate 400 average-rate 200 ntp server 82.219.4.31 source outside prefer ssl trust-point ASDM_TrustPoint0 outside webvpn enable outside anyconnect image disk0:/anyconnect-win-2.4.1012-k9.pkg 1 anyconnect profiles AnyConnectVPN_client_profile disk0:/AnyConnectVPN_client_profile.xml anyconnect profiles SSLAnyConnectVPN_client_profile disk0:/SSLAnyConnectVPN_client_profile.xml anyconnect enable tunnel-group-list enable group-policy GroupPolicy_AnyConnectVPN internal group-policy GroupPolicy_AnyConnectVPN attributes wins-server none dns-server value 4.2.2.2 vpn-tunnel-protocol ikev2 ssl-client ssl-clientless default-domain value aaa.local webvpn url-list none anyconnect profiles value AnyConnectVPN_client_profile type user group-policy GroupPolicy_SSLAnyConnectVPN internal group-policy GroupPolicy_SSLAnyConnectVPN attributes wins-server none dns-server value 4.2.2.2 vpn-tunnel-protocol ikev2 ssl-client default-domain value aaa.local webvpn anyconnect profiles value SSLAnyConnectVPN_client_profile type user username testuser password xxxxxxxxxxxxxxxxx encrypted privilege 0 username testuser attributes vpn-group-policy GroupPolicy_AnyConnectVPN tunnel-group SSLPOL type remote-access tunnel-group SSLPOL general-attributes default-group-policy GroupPolicy_AnyConnectVPN tunnel-group SSLAnyConnectVPN type remote-access tunnel-group SSLAnyConnectVPN general-attributes address-pool VPNPool default-group-policy GroupPolicy_SSLAnyConnectVPN tunnel-group SSLAnyConnectVPN webvpn-attributes group-alias SSLAnyConnectVPN enable ! class-map inspection_default match default-inspection-traffic ! ! policy-map type inspect dns preset_dns_map parameters message-length maximum 512 policy-map global_policy class inspection_default inspect dns preset_dns_map inspect esmtp inspect ftp inspect h323 h225 inspect h323 ras inspect ip-options inspect netbios inspect rsh inspect rtsp inspect sip inspect skinny inspect sqlnet inspect sunrpc inspect tftp inspect xdmcp ! service-policy global_policy global prompt hostname context call-home profile CiscoTAC-1 no active destination address http https://tools.cisco.com/its/service/oddce/services/DDCEService destination address email [email protected] destination transport-method http subscribe-to-alert-group diagnostic subscribe-to-alert-group environment subscribe-to-alert-group inventory periodic monthly subscribe-to-alert-group configuration periodic monthly subscribe-to-alert-group telemetry periodic daily Cryptochecksum:94a65341aa27d3929d5e92a32ba22120 : end

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• Permissions denied on apache rewrite module virtual host configuration

  - by sina

  All of a sudden I keep getting "Permissions denied" on apache 2 virtualhost once we moved it to its own conf file. I have tried all the suggestions I have found here but none work. Please can someone tell me what I am doing wrong? Thanks! <VirtualHost *:80> DocumentRoot "/var/www/mm" <Directory "/var/www/mm"> Options +Indexes +MultiViews +FollowSymLinks AllowOverride all Order deny,allow Allow from all AddType text/vnd.sun.j2me.app-descriptor .jad AddType application/vnd.rim.cod .cod </Directory> Alias /holdspace "/var/www/mm/holdspace" RewriteLogLevel 9 RewriteLog "/var/log/httpd/rewrite.log" RewriteEngine on # 91xx RewriteCond %{HTTP_USER_AGENT} BlackBerry.9105 RewriteRule ^/download/(.*) /holdspace/bb6-360x480/$1 [L] # 92xx RewriteCond %{HTTP_USER_AGENT} BlackBerry.9220 RewriteRule ^/download/(.*) /holdspace/bb5-320x240/$1 [L] Errors in error.log: [Wed May 28 12:44:58 2014] [error] [client 197.255.173.95] (13)Permission denied: access to /download/eazymoney.jad denied [Wed May 28 12:44:58 2014] [error] [client 197.255.173.95] (13)Permission denied: access to /error/HTTP_FORBIDDEN.html.var denied [Wed May 28 12:44:59 2014] [error] [client 197.255.173.95] (13)Permission denied: access to /favicon.ico denied [Wed May 28 12:44:59 2014] [error] [client 197.255.173.95] (13)Permission denied: access to /error/HTTP_FORBIDDEN.html.var denied [Wed May 28 12:44:59 2014] [error] [client 197.255.173.95] (13)Permission denied: access to /favicon.ico denied [Wed May 28 12:44:59 2014] [error] [client 197.255.173.95] (13)Permission denied: access to /error/HTTP_FORBIDDEN.html.var denied Errors in rewrite.log: 197.255.173.95 - - [28/May/2014:12:46:01 +0100] [41.203.113.103/sid#7fe41704ca28][rid#7fe417123378/initial/redir#1] (3) applying pattern '^/download/(.*)' to uri '/error/HTTP_FORBIDDEN.html.var' 197.255.173.95 - - [28/May/2014:12:46:01 +0100] [41.203.113.103/sid#7fe41704ca28][rid#7fe417123378/initial/redir#1] (3) applying pattern '^/download/(.*)' to uri '/error/HTTP_FORBIDDEN.html.var' Apache Configuration file: ServerTokens Prod ServerRoot "/etc/httpd" PidFile run/httpd.pid Timeout 60 KeepAlive Off MaxKeepAliveRequests 100 KeepAliveTimeout 15 <IfModule prefork.c> StartServers 8 MinSpareServers 5 MaxSpareServers 20 ServerLimit 256 MaxClients 256 MaxRequestsPerChild 4000 </IfModule> <IfModule worker.c> StartServers 4 MaxClients 300 MinSpareThreads 25 MaxSpareThreads 75 ThreadsPerChild 25 MaxRequestsPerChild 0 </IfModule> Listen 80 LoadModule auth_basic_module modules/mod_auth_basic.so LoadModule auth_digest_module modules/mod_auth_digest.so LoadModule authn_file_module modules/mod_authn_file.so LoadModule authn_alias_module modules/mod_authn_alias.so LoadModule authn_anon_module modules/mod_authn_anon.so LoadModule authn_dbm_module modules/mod_authn_dbm.so LoadModule authn_default_module modules/mod_authn_default.so LoadModule authz_host_module modules/mod_authz_host.so LoadModule authz_user_module modules/mod_authz_user.so LoadModule authz_owner_module modules/mod_authz_owner.so LoadModule authz_groupfile_module modules/mod_authz_groupfile.so LoadModule authz_dbm_module modules/mod_authz_dbm.so LoadModule authz_default_module modules/mod_authz_default.so LoadModule ldap_module modules/mod_ldap.so LoadModule authnz_ldap_module modules/mod_authnz_ldap.so LoadModule include_module modules/mod_include.so LoadModule log_config_module modules/mod_log_config.so LoadModule logio_module modules/mod_logio.so LoadModule env_module modules/mod_env.so LoadModule ext_filter_module modules/mod_ext_filter.so LoadModule mime_magic_module modules/mod_mime_magic.so LoadModule expires_module modules/mod_expires.so LoadModule deflate_module modules/mod_deflate.so LoadModule headers_module modules/mod_headers.so LoadModule usertrack_module modules/mod_usertrack.so LoadModule setenvif_module modules/mod_setenvif.so LoadModule mime_module modules/mod_mime.so LoadModule dav_module modules/mod_dav.so LoadModule status_module modules/mod_status.so LoadModule autoindex_module modules/mod_autoindex.so LoadModule info_module modules/mod_info.so LoadModule dav_fs_module modules/mod_dav_fs.so LoadModule vhost_alias_module modules/mod_vhost_alias.so LoadModule negotiation_module modules/mod_negotiation.so LoadModule dir_module modules/mod_dir.so LoadModule actions_module modules/mod_actions.so LoadModule speling_module modules/mod_speling.so LoadModule userdir_module modules/mod_userdir.so LoadModule alias_module modules/mod_alias.so LoadModule substitute_module modules/mod_substitute.so LoadModule rewrite_module modules/mod_rewrite.so LoadModule proxy_module modules/mod_proxy.so LoadModule proxy_ftp_module modules/mod_proxy_ftp.so LoadModule proxy_http_module modules/mod_proxy_http.so LoadModule proxy_ajp_module modules/mod_proxy_ajp.so LoadModule proxy_connect_module modules/mod_proxy_connect.so LoadModule cache_module modules/mod_cache.so LoadModule suexec_module modules/mod_suexec.so LoadModule disk_cache_module modules/mod_disk_cache.so LoadModule cgi_module modules/mod_cgi.so LoadModule version_module modules/mod_version.so Include conf.d/*.conf User apache Group apache ServerAdmin root@localhost ServerName sv001zma002.africa.int.myorg.com UseCanonicalName Off DocumentRoot "/var/www/html" <Directory /> Options FollowSymLinks AllowOverride None </Directory> <Directory "/var/www/html"> Options FollowSymLinks AllowOverride None Order allow,deny Allow from all </Directory> <IfModule mod_userdir.c> UserDir disabled </IfModule> DirectoryIndex index.html index.html.var AccessFileName .htaccess <Files ~ "^\.ht"> Order allow,deny Deny from all Satisfy All </Files> TypesConfig /etc/mime.types DefaultType text/plain <IfModule mod_mime_magic.c> MIMEMagicFile conf/magic </IfModule> HostnameLookups Off ErrorLog logs/error_log LogLevel warn LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"" combined LogFormat "%h %l %u %t \"%r\" %>s %b" common LogFormat "%{Referer}i -> %U" referer LogFormat "%{User-agent}i" agent CustomLog logs/access_log combined ServerSignature Off TraceEnable Off Alias /icons/ "/var/www/icons/" <Directory "/var/www/icons"> Options MultiViews FollowSymLinks AllowOverride None Order allow,deny Allow from all </Directory> <IfModule mod_dav_fs.c> DAVLockDB /var/lib/dav/lockdb </IfModule> ScriptAlias /cgi-bin/ "/var/www/cgi-bin/" <Directory "/var/www/cgi-bin"> AllowOverride None Options None Order allow,deny Allow from all </Directory> IndexOptions FancyIndexing VersionSort NameWidth=* HTMLTable Charset=UTF-8 AddIconByEncoding (CMP,/icons/compressed.gif) x-compress x-gzip AddIconByType (TXT,/icons/text.gif) text/* AddIconByType (IMG,/icons/image2.gif) image/* AddIconByType (SND,/icons/sound2.gif) audio/* AddIconByType (VID,/icons/movie.gif) video/* AddIcon /icons/binary.gif .bin .exe AddIcon /icons/binhex.gif .hqx AddIcon /icons/tar.gif .tar AddIcon /icons/world2.gif .wrl .wrl.gz .vrml .vrm .iv AddIcon /icons/compressed.gif .Z .z .tgz .gz .zip AddIcon /icons/a.gif .ps .ai .eps AddIcon /icons/layout.gif .html .shtml .htm .pdf AddIcon /icons/text.gif .txt AddIcon /icons/c.gif .c AddIcon /icons/p.gif .pl .py AddIcon /icons/f.gif .for AddIcon /icons/dvi.gif .dvi AddIcon /icons/uuencoded.gif .uu AddIcon /icons/script.gif .conf .sh .shar .csh .ksh .tcl AddIcon /icons/tex.gif .tex AddIcon /icons/bomb.gif core AddIcon /icons/back.gif .. AddIcon /icons/hand.right.gif README AddIcon /icons/folder.gif ^^DIRECTORY^^ AddIcon /icons/blank.gif ^^BLANKICON^^ DefaultIcon /icons/unknown.gif ReadmeName README.html HeaderName HEADER.html IndexIgnore .??* *~ *# HEADER* README* RCS CVS *,v *,t AddLanguage ca .ca AddLanguage cs .cz .cs AddLanguage da .dk AddLanguage de .de AddLanguage el .el AddLanguage en .en AddLanguage eo .eo AddLanguage es .es AddLanguage et .et AddLanguage fr .fr AddLanguage he .he AddLanguage hr .hr AddLanguage it .it AddLanguage ja .ja AddLanguage ko .ko AddLanguage ltz .ltz AddLanguage nl .nl AddLanguage nn .nn AddLanguage no .no AddLanguage pl .po AddLanguage pt .pt AddLanguage pt-BR .pt-br AddLanguage ru .ru AddLanguage sv .sv AddLanguage zh-CN .zh-cn AddLanguage zh-TW .zh-tw LanguagePriority en ca cs da de el eo es et fr he hr it ja ko ltz nl nn no pl pt pt-BR ru sv zh-CN zh-TW ForceLanguagePriority Prefer Fallback AddDefaultCharset UTF-8 AddType application/x-compress .Z AddType application/x-gzip .gz .tgz AddType application/x-x509-ca-cert .crt AddType application/x-pkcs7-crl .crl AddHandler type-map var AddType text/html .shtml AddOutputFilter INCLUDES .shtml ProxyErrorOverride On Alias /error/ "/var/www/error/" <IfModule mod_negotiation.c> <IfModule mod_include.c> <Directory "/var/www/error"> AllowOverride None Options IncludesNoExec AddOutputFilter Includes html AddHandler type-map var Order allow,deny Allow from all LanguagePriority en es de fr ForceLanguagePriority Prefer Fallback </Directory> ErrorDocument 400 /error/HTTP_BAD_REQUEST.html.var ErrorDocument 401 /error/HTTP_UNAUTHORIZED.html.var ErrorDocument 403 /error/HTTP_FORBIDDEN.html.var ErrorDocument 404 /error/HTTP_NOT_FOUND.html.var </IfModule> </IfModule> BrowserMatch "Mozilla/2" nokeepalive BrowserMatch "MSIE 4\.0b2;" nokeepalive downgrade-1.0 force-response-1.0 BrowserMatch "RealPlayer 4\.0" force-response-1.0 BrowserMatch "Java/1\.0" force-response-1.0 BrowserMatch "JDK/1\.0" force-response-1.0 BrowserMatch "Microsoft Data Access Internet Publishing Provider" redirect-carefully BrowserMatch "MS FrontPage" redirect-carefully BrowserMatch "^WebDrive" redirect-carefully BrowserMatch "^WebDAVFS/1.[0123]" redirect-carefully BrowserMatch "^gnome-vfs/1.0" redirect-carefully BrowserMatch "^XML Spy" redirect-carefully BrowserMatch "^Dreamweaver-WebDAV-SCM1" redirect-carefully ErrorDocument 400 "Bad Request"

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• Rails 2 and Ngnix: https pages can't load css or js (but will load graphics)

  - by Max Williams

  ADMISSION: i've posted this same question on stackoverflow, before realising it's probabaly better suited to superuser, but it kind of depends on the answer: If it turns out to be a problem in my nginx config, it's definitely superuser. If it turns out to be a problem in my Rails config (or code) then it's arguably stackoverflow. I'm adding some https pages to my rails site. In order to test it locally, i'm running my site under one mongrel_rails instance (on 3000) and nginx. I've managed to get my nginx config to the point where i can actually go to the https pages, and they load. Except, the javascript and css files all fail to load: looking in the Network tab in chrome web tools, i can see that it is trying to load them via an https url. Eg, one of the non-working file urls is https://cmw-local.co.uk/stylesheets/cmw-logged-out.css?1383759216 I have these set up (or at least think i do) in my nginx config to redirect to the http versions of the static files. This seems to be working for graphics, but not for css and js files. If i click on this in the Network tab, it takes me to the above url, which redirects to the http version. So, the redirect seems to be working in some sense, but not when they're loaded by an https page. Like i say, i thought i had this covered in the second try_files directive in my config below, but maybe not. Can anyone see what i'm doing wrong? thanks, Max Here's my nginx config - sorry it's a bit lengthy! I think the error is likely to be in the first (ssl) server block: server { listen 443 ssl; keepalive_timeout 70; ssl_certificate /home/max/work/charanga/elearn_container/elearn/config/nginx/certs/max-local-server.crt; ssl_certificate_key /home/max/work/charanga/elearn_container/elearn/config/nginx/certs/max-local-server.key; ssl_session_cache shared:SSL:10m; ssl_session_timeout 10m; ssl_protocols SSLv3 TLSv1; ssl_ciphers RC4:HIGH:!aNULL:!MD5; ssl_prefer_server_ciphers on; server_name elearning.dev cmw-dev.co.uk cmw-dev.com cmw-nginx.co.uk cmw-local.co.uk; root /home/max/work/charanga/elearn_container/elearn; # ensure that we serve css, js, other statics when requested # as SSL, but if the files don't exist (i.e. any non /basket controller) # then redirect to the non-https version location / { try_files $uri @non-ssl-redirect; } # securely serve everything under /basket (/basket/checkout etc) # we need general too, because of the email/username checking location ~ ^/(basket|general|cmw/account/check_username_availability) { # make sure cached copies are revalidated once they're stale add_header Cache-Control "public, must-revalidate, proxy-revalidate"; # this serves Rails static files that exist without running # other rewrite tests try_files $uri @rails-ssl; expires 1h; } location @non-ssl-redirect { return 301 http://$host$request_uri; } location @rails-ssl { proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header Host $http_host; proxy_redirect off; proxy_read_timeout 180; proxy_next_upstream off; proxy_pass http://127.0.0.1:3000; expires 0d; } } #upstream elrs { # server 127.0.0.1:3000; #} server { listen 80; server_name elearning.dev cmw-dev.co.uk cmw-dev.com cmw-nginx.co.uk cmw-local.co.uk; root /home/max/work/charanga/elearn_container/elearn; access_log /home/max/work/charanga/elearn_container/elearn/log/access.log; error_log /home/max/work/charanga/elearn_container/elearn/log/error.log debug; client_max_body_size 50M; index index.html index.htm; # gzip html, css & javascript, but don't gzip javascript for pre-SP2 MSIE6 (i.e. those *without* SV1 in their user-agent string) gzip on; gzip_http_version 1.1; gzip_vary on; gzip_comp_level 6; gzip_proxied any; gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript; #text/html # make sure gzip does not lose large gzipped js or css files # see http://blog.leetsoft.com/2007/7/25/nginx-gzip-ssl gzip_buffers 16 8k; # Disable gzip for certain browsers. #gzip_disable "MSIE [1-6].(?!.*SV1)"; gzip_disable "MSIE [1-6]"; # blank gif like it's 1995 location = /images/blank.gif { empty_gif; } # don't serve files beginning with dots location ~ /\. { access_log off; log_not_found off; deny all; } # we don't care if these are missing location = /robots.txt { log_not_found off; } location = /favicon.ico { log_not_found off; } location ~ affiliate.xml { log_not_found off; } location ~ copyright.xml { log_not_found off; } # convert urls with multiple slashes to a single / if ($request ~ /+ ) { rewrite ^(/)+(.*) /$2 break; } # X-Accel-Redirect # Don't tie up mongrels with serving the lesson zips or exes, let Nginx do it instead location /zips { internal; root /var/www/apps/e_learning_resource/shared/assets; } location /tmp { internal; root /; } location /mnt{ root /; } # resource library thumbnails should be served as usual location ~ ^/resource_library/.*/*thumbnail.jpg$ { if (!-f $request_filename) { rewrite ^(.*)$ /images/no-thumb.png break; } expires 1m; } # don't make Rails generate the dynamic routes to the dcr and swf, we'll do it here location ~ "lesson viewer.dcr" { rewrite ^(.*)$ "/assets/players/lesson viewer.dcr" break; } # we need this rule so we don't serve the older lessonviewer when the rule below is matched location = /assets/players/virgin_lesson_viewer/_cha5513/lessonViewer.swf { rewrite ^(.*)$ /assets/players/virgin_lesson_viewer/_cha5513/lessonViewer.swf break; } location ~ v6lessonViewer.swf { rewrite ^(.*)$ /assets/players/v6lessonViewer.swf break; } location ~ lessonViewer.swf { rewrite ^(.*)$ /assets/players/lessonViewer.swf break; } location ~ lgn111.dat { empty_gif; } # try to get autocomplete school names from memcache first, then # fallback to rails when we can't location /schools/autocomplete { set $memcached_key $uri?q=$arg_q; memcached_pass 127.0.0.1:11211; default_type text/html; error_page 404 =200 @rails; # 404 not really! Hand off to rails } location / { # make sure cached copies are revalidated once they're stale add_header Cache-Control "public, must-revalidate, proxy-revalidate"; # this serves Rails static files that exist without running other rewrite tests try_files $uri @rails; expires 1h; } location @rails { proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header Host $http_host; proxy_redirect off; proxy_read_timeout 180; proxy_next_upstream off; proxy_pass http://127.0.0.1:3000; expires 0d; } }

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• Unity3D draw call optimization : static batching VS manually draw mesh with MaterialPropertyBlock

  - by Heisenbug

  I've read Unity3D draw call batching documentation. I understood it, and I want to use it (or something similar) in order to optimize my application. My situation is the following: I'm drawing hundreds of 3d buildings. Each building can be represented using a Mesh (or a SubMesh for each building, but I don't thing this will affect performances) Each building can be textured with several combinations of texture patterns(walls, windows,..). Textures are stored into an Atlas for optimizaztion (see Texture2d.PackTextures) Texture mapping and facade pattern generation is done in fragment shader. The shader can be the same (except for few values) for all buildings, so I'd like to use a sharedMaterial in order to optimize parameters passed to the GPU. The main problem is that, even if I use an Atlas, share the material, and declare the objects as static to use static batching, there are few parameters(very fews, it could be just even a float I guess) that should be different for every draw call. I don't know exactly how to manage this situation using Unity3D. I'm trying 2 different solutions, none of them completely implemented. Solution 1 Build a GameObject for each building building (I don't like very much the overhead of a GameObject, anyway..) Prepare each GameObject to be static batched with StaticBatchingUtility.Combine. Pack all texture into an atlas Assign the parent game object of combined batched objects the Material (basically the shader and the atlas) Change some properties in the material before drawing an Object The problem is the point 5. Let's say I have to assign a different id to an object before drawing it, how can I do this? If I use a different material for each object I can't benefit of static batching. If I use a sharedMaterial and I modify a material property, all GameObjects will reference the same modified variable Solution 2 Build a Mesh for every building (sounds better, no GameObject overhead) Pack all textures into an Atlas Draw each mesh manually using Graphics.DrawMesh Customize each DrawMesh call using a MaterialPropertyBlock This would solve the issue related to slightly modify material properties for each draw call, but the documentation isn't clear on the following point: Does several consecutive calls to Graphic.DrawMesh with a different MaterialPropertyBlock would cause a new material to be instanced? Or Unity can understand that I'm modifying just few parameters while using the same material and is able to optimize that (in such a way that the big atlas is passed just once to the GPU)?

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• Content Management for WebCenter Installation Guide

  - by Gary Niu

  Overvew As we known, there are two way to install Content Management for WebCenter. One way is install it by WebCenter installer wizard, another way is to install it use their own installer. This guide is for the later one. For SSO purpose, I also mentioned how to config OID identity store for Content Management for WebCenter. Content Management for WebCenter( 10.1.3.5.1) Oracle Enterprise Linux R5U4 Basic Installation -bash-3.2$ ./setup.sh Please select your locale from the list.           1. Chinese-Simplified           2. Chinese-Traditional           3. Deutsch          *4. English-US           5. English-UK           6. Español           7. Français           8. Italiano           9. Japanese          10. Korean          11. Nederlands          12. Português-Brazil Choice? Throughout the install, when entering a text value, you can press Enter to accept the default that appears between square brackets ([]). When selecting from a list, you can select the choice followed by an asterisk by pressing Enter. Select installation type from the list.         *1. Install new server          2. Update a server Choice? Content Server Installation Directory Please enter the full pathname to the installation directory. Content Server Core Folder [/oracle/ucm/server]:/opt/oracle/ucm/server Create Directory         *1. yes          2. no Choice? Java virtual machine         *1. Sun Java 1.5.0_11 JDK          2. Specify a custom Java virtual machine Choice? Installing with Java version 1.5.0_11. Enter the location of the native file repository. This directory contains the native files checked in by contributors. Content Server Native Vault Folder [/opt/oracle/ucm/server/vault/]: Create Directory         *1. yes          2. no Choice? Enter the location of the web-viewable file repository. This directory contains files that can be accessed through the web server. Content Server Weblayout Folder [/opt/oracle/ucm/server/weblayout/]: Create Directory         *1. yes          2. no Choice? This server can be configured to manage its own authentication or to allow another master to act as an authentication proxy. Configure this server as a master or proxied server.         *1. Configure as a master server.          2. Configure as server proxied by a local master server. Choice? During installation, an admin server can be installed and configured to manage this server. If there is already an admin server on this system, you can have the installer configure it to administrate this server instead. Select admin server configuration.         *1. Install an admin server to manage this server.          2. Configure an existing admin server to manage this server.          3. Don't configure an admin server. Choice? Enter the location of an executable to start your web browser. This browser will be used to display the online help. Web Browser Path [/usr/bin/firefox]: Content Server System locale           1. Chinese-Simplified           2. Chinese-Traditional           3. Deutsch          *4. English-US           5. English-UK           6. Español           7. Français           8. Italiano           9. Japanese          10. Korean          11. Nederlands          12. Português-Brazil Choice? Please select the region for your timezone from the list.         *1. Use the timezone setting for your operating system          2. Pacific          3. America          4. Atlantic          5. Europe          6. Africa          7. Asia          8. Indian          9. Australia Choice? Please enter the port number that will be used to connect to the Content Server. This port must be otherwise unused. Content Server Port [4444]: Please enter the port number that will be used to connect to the Admin Server. This port must be otherwise unused. Admin Server Port [4440]: Enter a security filter for the server port. Hosts which are allowed to communicate directly with the server port may access any resources managed by the server. Insure that hosts which need access are included in the filter. See the installation guide for more details. Incoming connection address filter [127.0.0.1]:*.*.*.* *** Content Server URL Prefix The URL prefix specified here is used when generating HTML pages that refer to the contents of the weblayout directory within the installation. This prefix must be mapped in the web server Additional Document Directories section of the Content Management administration menu to the physical location of the weblayout directory. For example, "/idc/" would be used in your installation to refer to the URL http://ucm.company.com/idc which would be mapped in the web server to the physical location /oracle/ucm/server/weblayout. Web Server Relative Root [/idc/]: Enter the name of the local mail server. The server will contact this system to deliver email. Company Mail Server [mail]: Enter the e-mail address for the system administrator. Administrator E-Mail Address [sysadmin@mail]: *** Web Server Address Many generated HTML pages refer to the web server you are using. The address specified here will be used when generating those pages. The address should include the host and domain name in most cases. If your webserver is running on a port other than 80, append a colon and the port number. Examples: www.company.com, ucm.company.com:90 Web Server HTTP Address [yekki]:yekki.cn.oracle.com:7777 Enter the name for this instance. This name should be unique across your entire enterprise. It may not contain characters other than letters, numbers, and underscores. Server Instance Name [idc]: Enter a short label for this instance. This label is used on web pages to identify this instance. It should be less than 12 characters long. Server Instance Label [idc]: Enter a long description for this instance. Server Description [Content Server idc]: Web Server         *1. Apache          2. Sun ONE          3. Configure manually Choice? Please select a database from the list below to use with the Content Server. Content Server Database         *1. Oracle          2. Microsoft SQL Server 2005          3. Microsoft SQL Server 2000          4. Sybase          5. DB2          6. Custom JDBC settings          7. Skip database configuration Choice? Manually configure JDBC settings for this database          1. yes         *2. no Choice? Oracle Server Hostname [localhost]: Oracle Listener Port Number [1521]: *** Database User ID The user name is used to log into the database used by the content server. Oracle User [user]:YEKKI_OCSERVER *** Database Password The password is used to log into the database used by the content server. Oracle Password []:oracle Oracle Instance Name [ORACLE]:orcl Configure the JVM to find the JDBC driver in a specific jar file          1. yes         *2. no Choice? The installer can attempt to create the database tables or you can manually create them. If you choose to manually create the tables, you should create them now. Attempt to create database tables          1. yes         *2. no Choice? Select components to install.          1. ContentFolios: Collect related items in folios          2. Folders_g: Organize content into hierarchical folders          3. LinkManager8: Hypertext link management support          4. OracleTextSearch: External Oracle 11g database as search indexer support          5. ThreadedDiscussions: Threaded discussion management Enter numbers separated by commas to toggle, 0 to unselect all, F to finish: 1,2,3,4,5         *1. ContentFolios: Collect related items in folios         *2. Folders_g: Organize content into hierarchical folders         *3. LinkManager8: Hypertext link management support         *4. OracleTextSearch: External Oracle 11g database as search indexer support         *5. ThreadedDiscussions: Threaded discussion management Enter numbers separated by commas to toggle, 0 to unselect all, F to finish: F Checking configuration. . . Configuration OK. Review install settings. . . Content Server Core Folder: /opt/oracle/ucm/server Java virtual machine: Sun Java 1.5.0_11 JDK Content Server Native Vault Folder: /opt/oracle/ucm/server/vault/ Content Server Weblayout Folder: /opt/oracle/ucm/server/weblayout/ Proxy authentication through another server: no Install admin server: yes Web Browser Path: /usr/bin/firefox Content Server System locale: English-US Content Server Port: 4444 Admin Server Port: 4440 Incoming connection address filter: *.*.*.* Web Server Relative Root: /idc/ Company Mail Server: mail Administrator E-Mail Address: sysadmin@mail Web Server HTTP Address: yekki.cn.oracle.com:7777 Server Instance Name: idc Server Instance Label: idc Server Description: Content Server idc Web Server: Apache Content Server Database: Oracle Manually configure JDBC settings for this database: false Oracle Server Hostname: localhost Oracle Listener Port Number: 1521 Oracle User: YEKKI_OCSERVER Oracle Password: 6GP1gBgzSyKa4JW10U8UqqPznr/lzkNn/Ojf6M8GJ8I= Oracle Instance Name: orcl Configure the JVM to find the JDBC driver in a specific jar file: false Attempt to create database tables: no Components: ContentFolios,Folders_g,LinkManager8,OracleTextSearch,ThreadedDiscussions Proceed with install         *1. Proceed          2. Change configuration          3. Recheck the configuration          4. Abort installation Choice? Finished install type Install with warnings at 4/2/10 12:32 AM. Run Scripts -bash-3.2$ ./wc_contentserverconfig.sh /opt/oracle/ucm/server /mnt/hgfs/SOFTWARE/ofm_ucm_generic_10.1.3.5.1_disk1_1of1/ContentServer/webcenter-conf Installing '/mnt/hgfs/SOFTWARE/ofm_ucm_generic_10.1.3.5.1_disk1_1of1/ContentServer/webcenter-conf/CS10gR35UpdateBundle.zip' Service 'DELETE_DOC' Extended Service 'DELETE_BYREV_REVISION' Extended Installing '/mnt/hgfs/SOFTWARE/ofm_ucm_generic_10.1.3.5.1_disk1_1of1/ContentServer/webcenter-conf/ContentAccess/ContentAccess-linux.zip' (internal)      04.02 00:40:38.019      main    updateDocMetaDefinitionV11: adding decimal column Installing '/opt/oracle/ucm/server/custom/CS10gR35UpdateBundle/extras/Folders_g.zip' Installing '/opt/oracle/ucm/server/custom/CS10gR35UpdateBundle/extras/FusionLibraries.zip' Installing '/opt/oracle/ucm/server/custom/CS10gR35UpdateBundle/extras/JpsUserProvider.zip' Installing '/mnt/hgfs/SOFTWARE/ofm_ucm_generic_10.1.3.5.1_disk1_1of1/ContentServer/webcenter-conf/WcConfigure.zip' Apr 2, 2010 12:41:24 AM oracle.security.jps.internal.core.util.JpsConfigUtil getPasswordCredential WARNING: A password credential is expected; instead found . Apr 2, 2010 12:41:24 AM oracle.security.jps.internal.idstore.util.IdentityStoreUtil getUnamePwdFromCredStore WARNING: The credential with map JPS and key ldap.credential does not exist. Apr 2, 2010 12:41:27 AM oracle.security.jps.internal.core.util.JpsConfigUtil getPasswordCredential WARNING: A password credential is expected; instead found . Apr 2, 2010 12:41:27 AM oracle.security.jps.internal.idstore.util.IdentityStoreUtil getUnamePwdFromCredStore WARNING: The credential with map JPS and key ldap.credential does not exist. Apr 2, 2010 12:41:28 AM oracle.security.jps.internal.core.util.JpsConfigUtil getPasswordCredential WARNING: A password credential is expected; instead found . Apr 2, 2010 12:41:28 AM oracle.security.jps.internal.idstore.util.IdentityStoreUtil getUnamePwdFromCredStore WARNING: The credential with map JPS and key ldap.credential does not exist. Restart Content Server to apply updates. Configuring Apache Web Server append the following lines at httpd.conf: include "/opt/oracle/ucm/server/data/users/apache22/apache.conf" Configuring the Identity Store( Optional ) 1.  Stop Oracle Content Server and the Admin Server 2.  Update the Oracle Content Server's JPS configuration file, jps-config.xml: a. add a service instance <serviceInstance provider="idstore.ldap.provider" name="idstore.oid"> <property name="subscriber.name" value="dc=cn,dc=oracle,dc=com"></property> <property name="idstore.type" value="OID"></property> <property name="security.principal.key" value="ldap.credential"></property> <property name="security.principal.alias" value="JPS"></property> <property name="ldap.url" value="ldap://yekki.cn.oracle.com:3060"></property> <extendedProperty> <name>user.search.bases</name> <values> <value>cn=users,dc=cn,dc=oracle,dc=com</value> </values> </extendedProperty> <extendedProperty> <name>group.search.bases</name> <values> <value>cn=groups,dc=cn,dc=oracle,dc=com</value> </values> </extendedProperty> <property name="username.attr" value="uid"></property> <property name="user.login.attr" value="uid"></property> <property name="groupname.attr" value="cn"></property> </serviceInstance> b. Ensure that the <jpsContext> entry in the jps-config.xml file refers to the new serviceInstance, that is, idstore.oid and not idstore.ldap: <jpsContext name="default"> <serviceInstanceRef ref="idstore.oid"/> 3. Run the new script to setup the credentials for idstore.oid in the credential store: cd CONTENT_SERVER_HOME/custom/FusionLibraries/tools -bash-3.2$ ./run_credtool.sh Buildfile: ./../tools/credtool.xml     [input] skipping input as property action has already been set.     [input] Alias: [JPS]     [input] Key: [ldap.credential]     [input] User Name: cn=orcladmin     [input] Password: welcome1     [input] JPS Config: [/opt/oracle/ucm/server/custom/FusionLibraries/tools/../../../config/jps-config.xml] manage-creds:      [echo] @@@ Help: run 'ant manage-creds' command to see the detailed usage      [java] Using default context in /opt/oracle/ucm/server/custom/FusionLibraries/tools/../../../config/jps-config.xml file for credential store.      [java] Credential store location : /opt/oracle/ucm/server/config      [java] Credential with map JPS key ldap.credential stored successfully!      [java]      [java]      [java]     Credential for map JPS and key ldap.credential is:      [java]             PasswordCredential name : cn=orcladmin      [java]             PasswordCredential password : welcome1 BUILD SUCCESSFUL Total time: 1 minute 27 seconds Testing 1. acces http://yekki.cn.oracle.com:7777/idc 2. login in with OID user, for example: orcladmin/welcome1 3. make sure your JpsUserProvider status is "good"

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• Do not use “using” in WCF Client

  - by oazabir

  You know that any IDisposable object must be disposed using using. So, you have been using using to wrap WCF service’s ChannelFactory and Clients like this: using(var client = new SomeClient()) {. ..} Or, if you are doing it the hard and slow way (without really knowing why), then: using(var factory = new ChannelFactory<ISomeService>()) {var channel= factory.CreateChannel();...} That’s what we have all learnt in school right? We have learnt it wrong! When there’s a network related error or the connection is broken, or the call is timed out before Dispose is called by the using keyword, then it results in the following exception when the using keyword tries to dispose the channel: failed: System.ServiceModel.CommunicationObjectFaultedException : The communication object, System.ServiceModel.Channels.ServiceChannel, cannot be used for communication because it is in the Faulted state. Server stack trace: at System.ServiceModel.Channels.CommunicationObject.Close(TimeSpan timeout) Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type) at System.ServiceModel.ICommunicationObject.Close(TimeSpan timeout) at System.ServiceModel.ClientBase`1.System.ServiceModel.ICommunicationObject.Close(TimeSpan timeout) at System.ServiceModel.ClientBase`1.Close() at System.ServiceModel.ClientBase`1.System.IDisposable.Dispose() There are various reasons for which the underlying connection can be at broken state before the using block is completed and the .Dispose() is called. Common problems like network connection dropping, IIS doing an app pool recycle at that moment, some proxy sitting between you and the service dropping the connection for various reasons and so on. The point is, it might seem like a corner case, but it’s a likely corner case. If you are building a highly available client, you need to treat this properly before you go-live. So, do NOT use using on WCF Channel/Client/ChannelFactory. Instead you need to use an alternative. Here’s what you can do: First create an extension method. public static class WcfExtensions{ public static void Using<T>(this T client, Action<T> work) where T : ICommunicationObject { try { work(client); client.Close(); } catch (CommunicationException e) { client.Abort(); } catch (TimeoutException e) { client.Abort(); } catch (Exception e) { client.Abort(); throw; } }} Then use this instead of the using keyword: new SomeClient().Using(channel => { channel.Login(username, password);}); Or if you are using ChannelFactory then: new ChannelFactory<ISomeService>().Using(channel => { channel.Login(username, password);}); Enjoy!

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• C#/.NET Little Wonders: The Concurrent Collections (1 of 3)

  - by James Michael Hare

  Once again we consider some of the lesser known classes and keywords of C#.  In the next few weeks, we will discuss the concurrent collections and how they have changed the face of concurrent programming. This week’s post will begin with a general introduction and discuss the ConcurrentStack<T> and ConcurrentQueue<T>.  Then in the following post we’ll discuss the ConcurrentDictionary<T> and ConcurrentBag<T>.  Finally, we shall close on the third post with a discussion of the BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. A brief history of collections In the beginning was the .NET 1.0 Framework.  And out of this framework emerged the System.Collections namespace, and it was good.  It contained all the basic things a growing programming language needs like the ArrayList and Hashtable collections.  The main problem, of course, with these original collections is that they held items of type object which means you had to be disciplined enough to use them correctly or you could end up with runtime errors if you got an object of a type you weren't expecting. Then came .NET 2.0 and generics and our world changed forever!  With generics the C# language finally got an equivalent of the very powerful C++ templates.  As such, the System.Collections.Generic was born and we got type-safe versions of all are favorite collections.  The List<T> succeeded the ArrayList and the Dictionary<TKey,TValue> succeeded the Hashtable and so on.  The new versions of the library were not only safer because they checked types at compile-time, in many cases they were more performant as well.  So much so that it's Microsoft's recommendation that the System.Collections original collections only be used for backwards compatibility. So we as developers came to know and love the generic collections and took them into our hearts and embraced them.  The problem is, thread safety in both the original collections and the generic collections can be problematic, for very different reasons. Now, if you are only doing single-threaded development you may not care – after all, no locking is required.  Even if you do have multiple threads, if a collection is “load-once, read-many” you don’t need to do anything to protect that container from multi-threaded access, as illustrated below: 1: public static class OrderTypeTranslator 2: { 3: // because this dictionary is loaded once before it is ever accessed, we don't need to synchronize 4: // multi-threaded read access 5: private static readonly Dictionary<string, char> _translator = new Dictionary<string, char> 6: { 7: {"New", 'N'}, 8: {"Update", 'U'}, 9: {"Cancel", 'X'} 10: }; 11:  12: // the only public interface into the dictionary is for reading, so inherently thread-safe 13: public static char? Translate(string orderType) 14: { 15: char charValue; 16: if (_translator.TryGetValue(orderType, out charValue)) 17: { 18: return charValue; 19: } 20:  21: return null; 22: } 23: } Unfortunately, most of our computer science problems cannot get by with just single-threaded applications or with multi-threading in a load-once manner.  Looking at  today's trends, it's clear to see that computers are not so much getting faster because of faster processor speeds -- we've nearly reached the limits we can push through with today's technologies -- but more because we're adding more cores to the boxes.  With this new hardware paradigm, it is even more important to use multi-threaded applications to take full advantage of parallel processing to achieve higher application speeds. So let's look at how to use collections in a thread-safe manner. Using historical collections in a concurrent fashion The early .NET collections (System.Collections) had a Synchronized() static method that could be used to wrap the early collections to make them completely thread-safe.  This paradigm was dropped in the generic collections (System.Collections.Generic) because having a synchronized wrapper resulted in atomic locks for all operations, which could prove overkill in many multithreading situations.  Thus the paradigm shifted to having the user of the collection specify their own locking, usually with an external object: 1: public class OrderAggregator 2: { 3: private static readonly Dictionary<string, List<Order>> _orders = new Dictionary<string, List<Order>>(); 4: private static readonly _orderLock = new object(); 5:  6: public void Add(string accountNumber, Order newOrder) 7: { 8: List<Order> ordersForAccount; 9:  10: // a complex operation like this should all be protected 11: lock (_orderLock) 12: { 13: if (!_orders.TryGetValue(accountNumber, out ordersForAccount)) 14: { 15: _orders.Add(accountNumber, ordersForAccount = new List<Order>()); 16: } 17:  18: ordersForAccount.Add(newOrder); 19: } 20: } 21: } Notice how we’re performing several operations on the dictionary under one lock.  With the Synchronized() static methods of the early collections, you wouldn’t be able to specify this level of locking (a more macro-level).  So in the generic collections, it was decided that if a user needed synchronization, they could implement their own locking scheme instead so that they could provide synchronization as needed. The need for better concurrent access to collections Here’s the problem: it’s relatively easy to write a collection that locks itself down completely for access, but anything more complex than that can be difficult and error-prone to write, and much less to make it perform efficiently!  For example, what if you have a Dictionary that has frequent reads but in-frequent updates?  Do you want to lock down the entire Dictionary for every access?  This would be overkill and would prevent concurrent reads.  In such cases you could use something like a ReaderWriterLockSlim which allows for multiple readers in a lock, and then once a writer grabs the lock it blocks all further readers until the writer is done (in a nutshell).  This is all very complex stuff to consider. Fortunately, this is where the Concurrent Collections come in.  The Parallel Computing Platform team at Microsoft went through great pains to determine how to make a set of concurrent collections that would have the best performance characteristics for general case multi-threaded use. Now, as in all things involving threading, you should always make sure you evaluate all your container options based on the particular usage scenario and the degree of parallelism you wish to acheive. This article should not be taken to understand that these collections are always supperior to the generic collections. Each fills a particular need for a particular situation. Understanding what each container is optimized for is key to the success of your application whether it be single-threaded or multi-threaded. General points to consider with the concurrent collections The MSDN points out that the concurrent collections all support the ICollection interface. However, since the collections are already synchronized, the IsSynchronized property always returns false, and SyncRoot always returns null.  Thus you should not attempt to use these properties for synchronization purposes. Note that since the concurrent collections also may have different operations than the traditional data structures you may be used to.  Now you may ask why they did this, but it was done out of necessity to keep operations safe and atomic.  For example, in order to do a Pop() on a stack you have to know the stack is non-empty, but between the time you check the stack’s IsEmpty property and then do the Pop() another thread may have come in and made the stack empty!  This is why some of the traditional operations have been changed to make them safe for concurrent use. In addition, some properties and methods in the concurrent collections achieve concurrency by creating a snapshot of the collection, which means that some operations that were traditionally O(1) may now be O(n) in the concurrent models.  I’ll try to point these out as we talk about each collection so you can be aware of any potential performance impacts.  Finally, all the concurrent containers are safe for enumeration even while being modified, but some of the containers support this in different ways (snapshot vs. dirty iteration).  Once again I’ll highlight how thread-safe enumeration works for each collection. ConcurrentStack<T>: The thread-safe LIFO container The ConcurrentStack<T> is the thread-safe counterpart to the System.Collections.Generic.Stack<T>, which as you may remember is your standard last-in-first-out container.  If you think of algorithms that favor stack usage (for example, depth-first searches of graphs and trees) then you can see how using a thread-safe stack would be of benefit. The ConcurrentStack<T> achieves thread-safe access by using System.Threading.Interlocked operations.  This means that the multi-threaded access to the stack requires no traditional locking and is very, very fast! For the most part, the ConcurrentStack<T> behaves like it’s Stack<T> counterpart with a few differences: Pop() was removed in favor of TryPop() Returns true if an item existed and was popped and false if empty. PushRange() and TryPopRange() were added Allows you to push multiple items and pop multiple items atomically. Count takes a snapshot of the stack and then counts the items. This means it is a O(n) operation, if you just want to check for an empty stack, call IsEmpty instead which is O(1). ToArray() and GetEnumerator() both also take snapshots. This means that iteration over a stack will give you a static view at the time of the call and will not reflect updates. Pushing on a ConcurrentStack<T> works just like you’d expect except for the aforementioned PushRange() method that was added to allow you to push a range of items concurrently. 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: // but you can also push multiple items in one atomic operation (no interleaves) 7: stack.PushRange(new [] { "Second", "Third", "Fourth" }); For looking at the top item of the stack (without removing it) the Peek() method has been removed in favor of a TryPeek().  This is because in order to do a peek the stack must be non-empty, but between the time you check for empty and the time you execute the peek the stack contents may have changed.  Thus the TryPeek() was created to be an atomic check for empty, and then peek if not empty: 1: // to look at top item of stack without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (stack.TryPeek(out item)) 5: { 6: Console.WriteLine("Top item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Stack was empty."); 11: } Finally, to remove items from the stack, we have the TryPop() for single, and TryPopRange() for multiple items.  Just like the TryPeek(), these operations replace Pop() since we need to ensure atomically that the stack is non-empty before we pop from it: 1: // to remove items, use TryPop or TryPopRange to get multiple items atomically (no interleaves) 2: if (stack.TryPop(out item)) 3: { 4: Console.WriteLine("Popped " + item); 5: } 6:  7: // TryPopRange will only pop up to the number of spaces in the array, the actual number popped is returned. 8: var poppedItems = new string[2]; 9: int numPopped = stack.TryPopRange(poppedItems); 10:  11: foreach (var theItem in poppedItems.Take(numPopped)) 12: { 13: Console.WriteLine("Popped " + theItem); 14: } Finally, note that as stated before, GetEnumerator() and ToArray() gets a snapshot of the data at the time of the call.  That means if you are enumerating the stack you will get a snapshot of the stack at the time of the call.  This is illustrated below: 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: var results = stack.GetEnumerator(); 7:  8: // but you can also push multiple items in one atomic operation (no interleaves) 9: stack.PushRange(new [] { "Second", "Third", "Fourth" }); 10:  11: while(results.MoveNext()) 12: { 13: Console.WriteLine("Stack only has: " + results.Current); 14: } The only item that will be printed out in the above code is "First" because the snapshot was taken before the other items were added. This may sound like an issue, but it’s really for safety and is more correct.  You don’t want to enumerate a stack and have half a view of the stack before an update and half a view of the stack after an update, after all.  In addition, note that this is still thread-safe, whereas iterating through a non-concurrent collection while updating it in the old collections would cause an exception. ConcurrentQueue<T>: The thread-safe FIFO container The ConcurrentQueue<T> is the thread-safe counterpart of the System.Collections.Generic.Queue<T> class.  The concurrent queue uses an underlying list of small arrays and lock-free System.Threading.Interlocked operations on the head and tail arrays.  Once again, this allows us to do thread-safe operations without the need for heavy locks! The ConcurrentQueue<T> (like the ConcurrentStack<T>) has some departures from the non-concurrent counterpart.  Most notably: Dequeue() was removed in favor of TryDequeue(). Returns true if an item existed and was dequeued and false if empty. Count does not take a snapshot It subtracts the head and tail index to get the count.  This results overall in a O(1) complexity which is quite good.  It’s still recommended, however, that for empty checks you call IsEmpty instead of comparing Count to zero. ToArray() and GetEnumerator() both take snapshots. This means that iteration over a queue will give you a static view at the time of the call and will not reflect updates. The Enqueue() method on the ConcurrentQueue<T> works much the same as the generic Queue<T>: 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5: queue.Enqueue("Second"); 6: queue.Enqueue("Third"); For front item access, the TryPeek() method must be used to attempt to see the first item if the queue.  There is no Peek() method since, as you’ll remember, we can only peek on a non-empty queue, so we must have an atomic TryPeek() that checks for empty and then returns the first item if the queue is non-empty. 1: // to look at first item in queue without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (queue.TryPeek(out item)) 5: { 6: Console.WriteLine("First item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Queue was empty."); 11: } Then, to remove items you use TryDequeue().  Once again this is for the same reason we have TryPeek() and not Peek(): 1: // to remove items, use TryDequeue. If queue is empty returns false. 2: if (queue.TryDequeue(out item)) 3: { 4: Console.WriteLine("Dequeued first item " + item); 5: } Just like the concurrent stack, the ConcurrentQueue<T> takes a snapshot when you call ToArray() or GetEnumerator() which means that subsequent updates to the queue will not be seen when you iterate over the results.  Thus once again the code below will only show the first item, since the other items were added after the snapshot. 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5:  6: var iterator = queue.GetEnumerator(); 7:  8: queue.Enqueue("Second"); 9: queue.Enqueue("Third"); 10:  11: // only shows First 12: while (iterator.MoveNext()) 13: { 14: Console.WriteLine("Dequeued item " + iterator.Current); 15: } Using collections concurrently You’ll notice in the examples above I stuck to using single-threaded examples so as to make them deterministic and the results obvious.  Of course, if we used these collections in a truly multi-threaded way the results would be less deterministic, but would still be thread-safe and with no locking on your part required! For example, say you have an order processor that takes an IEnumerable<Order> and handles each other in a multi-threaded fashion, then groups the responses together in a concurrent collection for aggregation.  This can be done easily with the TPL’s Parallel.ForEach(): 1: public static IEnumerable<OrderResult> ProcessOrders(IEnumerable<Order> orderList) 2: { 3: var proxy = new OrderProxy(); 4: var results = new ConcurrentQueue<OrderResult>(); 5:  6: // notice that we can process all these in parallel and put the results 7: // into our concurrent collection without needing any external locking! 8: Parallel.ForEach(orderList, 9: order => 10: { 11: var result = proxy.PlaceOrder(order); 12:  13: results.Enqueue(result); 14: }); 15:  16: return results; 17: } Summary Obviously, if you do not need multi-threaded safety, you don’t need to use these collections, but when you do need multi-threaded collections these are just the ticket! The plethora of features (I always think of the movie The Three Amigos when I say plethora) built into these containers and the amazing way they acheive thread-safe access in an efficient manner is wonderful to behold. Stay tuned next week where we’ll continue our discussion with the ConcurrentBag<T> and the ConcurrentDictionary<TKey,TValue>. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here.   Tweet Technorati Tags: C#,.NET,Concurrent Collections,Collections,Multi-Threading,Little Wonders,BlackRabbitCoder,James Michael Hare

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• Replacing “if”s with your own number system

  - by Michael Williamson

  During our second code retreat at Red Gate, the restriction for one of the sessions was disallowing the use of if statements. That includes other constructs that have the same effect, such as switch statements or loops that will only be executed zero or one times. The idea is to encourage use of polymorphism instead, and see just how far it can be used to get rid of “if”s. The main place where people struggled to get rid of numbers from their implementation of Conway’s Game of Life was the piece of code that decides whether a cell is live or dead in the next generation. For instance, for a cell that’s currently live, the code might look something like this: if (numberOfNeighbours == 2 || numberOfNeighbours == 3) { return CellState.LIVE; } else { return CellState.DEAD; } The problem is that we need to change behaviour depending on the number of neighbours each cell has, but polymorphism only allows us to switch behaviour based on the type of a value. It follows that the solution is to make different numbers have different types: public interface IConwayNumber { IConwayNumber Increment(); CellState LiveCellNextGeneration(); } public class Zero : IConwayNumber { public IConwayNumber Increment() { return new One(); } public CellState LiveCellNextGeneration() { return CellState.DEAD; } } public class One : IConwayNumber { public IConwayNumber Increment() { return new Two(); } public CellState LiveCellNextGeneration() { return CellState.LIVE; } } public class Two : IConwayNumber { public IConwayNumber Increment() { return new ThreeOrMore(); } public CellState LiveCellNextGeneration() { return CellState.LIVE; } } public class ThreeOrMore : IConwayNumber { public IConwayNumber Increment() { return this; } public CellState LiveCellNextGeneration() { return CellState.DEAD; } } In the code that counts the number of neighbours, we use our new number system by starting with Zero and incrementing when we find a neighbour. To choose the next state of the cell, rather than inspecting the number of neighbours, we ask the number of neighbours for the next state directly: return numberOfNeighbours.LiveCellNextGeneration(); And now we have no “if”s! If C# had double-dispatch, or if we used the visitor pattern, we could move the logic for choosing the next cell out of the number classes, which might feel a bit more natural. I suspect that reimplementing the natural numbers is still going to feel about the same amount of crazy though.

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• NHibernate 2 Beginner's Guide Review

  - by Ricardo Peres

  OK, here's the review I promised a while ago. This is a beginner's introduction to NHibernate, so if you have already some experience with NHibernate, you will notice it lacks a lot of concepts and information. It starts with a good description of NHibernate and why would we use it. It goes on describing basic mapping scenarios having primary keys generated with the HiLo or Identity algorithms, without actually explaining why would we choose one over the other. As for mapping, the book talks about XML mappings and provides a simple example of Fluent NHibernate, comparing it to its XML counterpart. When it comes to relations, it covers one-to-many/many-to-one and many-to-many, not one-to-one relations, but only talks briefly about lazy loading, which is, IMO, an important concept. Only Bags are described, not any of the other collection types. The log4net configuration description gets it's own chapter, which I find excessive. The chapter on configuration merely lists the most common properties for configuring NHibernate, both in XML and in code. Querying only talks about loading by ID (using Get, not Load) and using Criteria API, on which a paging example is presented as well as some common filtering options (property equals/like/between to, no examples on conjunction/disjunction, however). There's a chapter fully dedicated to ASP.NET, which explains how we can use NHibernate in web applications. It basically talks about ASP.NET concepts, though. Following it, another chapter explains how we can build our own ASP.NET providers using NHibernate (Membership, Role). The available entity generators for NHibernate are referred and evaluated on a chapter of their own, the list is fine (CodeSmith, nhib-gen, AjGenesis, Visual NHibernate, MyGeneration, NGen, NHModeler, Microsoft T4 (?) and hbm2net), examples are provided whenever possible, however, I have some problems with some of the evaluations: for example, Visual NHibernate scores 5 out of 5 on Visual Studio integration, which simply does not exist! I suspect the author means to say that it can be launched from inside Visual Studio, but then, what can't? Finally, there's a chapter I really don't understand. It seems like a bag where a lot of things are thrown in, like NHibernate Burrow (which actually isn't explained at all), Blog.Net components, CSS template conversion and web.config settings related to the maximum request length for file uploads and ending with XML configuration, with the help of GhostDoc. Like I said, the book is only good for absolute beginners, it does a fair job in explaining the very basics, but lack a lot of not-so-basic concepts. Among other things, it lacks: Inheritance mapping strategies (table per class hierarchy, table per class, table per concrete class) Load versus Get usage Other usefull ISession methods First level cache (Identity Map pattern) Other collection types other that Bag (Set, List, Map, IdBag, etc Fetch options User Types Filters Named queries LINQ examples HQL examples And that's it! I hope you find this review useful. The link to the book site is https://www.packtpub.com/nhibernate-2-x-beginners-guide/book

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• Ubuntu Software Center starts, then crashes before fully loaded [closed]

  - by Nathan Weisser

  Possible Duplicate: Software center not opening I am brand new to Linux and Ubuntu, and I couldn't install GIMP without the software center. I looked up earlier how to fix it, and it said to fix my sources list, and I did, but now i get a new error in the terminal. 2012-08-14 15:29:08,941 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None' 2012-08-14 15:29:08,954 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True 2012-08-14 15:29:09,407 - softwarecenter.ui.gtk3.app - INFO - building local database 2012-08-14 15:29:09,408 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open() 2012-08-14 15:29:17,308 - softwarecenter.db.update - WARNING - Problem creating rebuild path '/var/cache/software-center/xapian_rb'. 2012-08-14 15:29:17,309 - softwarecenter.db.update - WARNING - Please check you have the relevant permissions. 2012-08-14 15:29:17,309 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True 2012-08-14 15:29:18,039 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file 2012-08-14 15:29:18,431 - softwarecenter.ui.gtk3.app - INFO - show_available_packages: search_text is '', app is None. 2012-08-14 15:29:19,153 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open() Traceback (most recent call last): File "/usr/bin/software-center", line 176, in <module> app.run(args) File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1422, in run self.show_available_packages(args) File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1352, in show_available_packages self.view_manager.set_active_view(ViewPages.AVAILABLE) File "/usr/share/software-center/softwarecenter/ui/gtk3/session/viewmanager.py", line 154, in set_active_view view_widget.init_view() File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/availablepane.py", line 136, in init_view SoftwarePane.init_view(self) File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/softwarepane.py", line 215, in init_view self.icons, self.show_ratings) File "/usr/share/software-center/softwarecenter/ui/gtk3/views/appview.py", line 69, in __init__ self.helper = AppPropertiesHelper(db, cache, icons) File "/usr/share/software-center/softwarecenter/ui/gtk3/models/appstore2.py", line 109, in __init__ softwarecenter.paths.APP_INSTALL_PATH) File "/usr/share/software-center/softwarecenter/db/categories.py", line 255, in parse_applications_menu category = self._parse_menu_tag(child) File "/usr/share/software-center/softwarecenter/db/categories.py", line 444, in _parse_menu_tag query = self._parse_include_tag(element) File "/usr/share/software-center/softwarecenter/db/categories.py", line 402, in _parse_include_tag xapian.Query.OP_AND) File "/usr/share/software-center/softwarecenter/db/categories.py", line 341, in _parse_and_or_not_tag operator_elem, xapian.Query(), xapian.Query.OP_OR) File "/usr/share/software-center/softwarecenter/db/categories.py", line 385, in _parse_and_or_not_tag q = self.db.xapian_parser.parse_query(s, File "/usr/share/software-center/softwarecenter/db/database.py", line 174, in xapian_parser xapian_parser = self._get_new_xapian_parser() File "/usr/share/software-center/softwarecenter/db/database.py", line 200, in _get_new_xapian_parser xapian_parser.set_database(self.xapiandb) File "/usr/share/software-center/softwarecenter/db/database.py", line 166, in xapiandb self._db_per_thread[thread_name] = self._get_new_xapiandb() File "/usr/share/software-center/softwarecenter/db/database.py", line 179, in _get_new_xapiandb xapiandb = xapian.Database(self._db_pathname) File "/usr/lib/python2.7/dist-packages/xapian/__init__.py", line 3666, in __init__ _xapian.Database_swiginit(self,_xapian.new_Database(*args)) xapian.DatabaseOpeningError: Couldn't detect type of database I'm not sure how to fix the errors, and I couldn't find a topic on them anywhere. Be nice, because I am a two-day old Linux user :/ Tell me if you need my Sources list

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• Unable to run Ubuntu Software center in 12.04

  - by Noye

  I think I've tried everything found. It is on just for a second. I can't even send an error report. What should I do? thanks in advance. so this is what I get after typing software-center in terminal (sorry, not as a code): 2012-06-16 22:54:17,610 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None' 2012-06-16 22:54:17,617 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True 2012-06-16 22:54:18,142 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file 2012-06-16 22:54:18,697 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open() Traceback (most recent call last): File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 243, in open self._cache = apt.Cache(GtkMainIterationProgress()) File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 102, in __init__ self.open(progress) File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 149, in open self._list.read_main_list() SystemError: E:Typ „ain“ je neznámy na riadku 2 v zozname zdrojov /etc/apt/sources.list.d/yannubuntu-boot-repair-precise.list 2012-06-16 22:54:21,916 - softwarecenter.db.enquire - ERROR - _get_estimate_nr_apps_and_nr_pkgs failed Traceback (most recent call last): File "/usr/share/software-center/softwarecenter/db/enquire.py", line 115, in _get_estimate_nr_apps_and_nr_pkgs tmp_matches = enquire.get_mset(0, len(self.db), None, xfilter) File "/usr/share/software-center/softwarecenter/db/appfilter.py", line 89, in __call__ if (not pkgname in self.cache and File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 263, in __contains__ return self._cache.__contains__(k) AttributeError: 'NoneType' object has no attribute '__contains__' Traceback (most recent call last): File "/usr/bin/software-center", line 176, in app.run(args) File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1358, in run self.show_available_packages(args) File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1288, in show_available_packages self.view_manager.set_active_view(ViewPages.AVAILABLE) File "/usr/share/software-center/softwarecenter/ui/gtk3/session/viewmanager.py", line 149, in set_active_view view_widget.init_view() File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/availablepane.py", line 168, in init_view self.apps_filter) File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 240, in __init__ self.build(desktopdir) File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 491, in build self._build_homepage_view() File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 266, in _build_homepage_view self._append_whats_new() File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 430, in _append_whats_new whats_new_cat = self._update_whats_new_content() File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 419, in _update_whats_new_content docs = whats_new_cat.get_documents(self.db) File "/usr/share/software-center/softwarecenter/db/categories.py", line 124, in get_documents nonblocking_load=False) File "/usr/share/software-center/softwarecenter/db/enquire.py", line 317, in set_query self._blocking_perform_search() File "/usr/share/software-center/softwarecenter/db/enquire.py", line 212, in _blocking_perform_search matches = enquire.get_mset(0, self.limit, None, xfilter) File "/usr/share/software-center/softwarecenter/db/appfilter.py", line 89, in __call__ if (not pkgname in self.cache and File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 263, in __contains__ return self._cache.__contains__(k) AttributeError: 'NoneType' object has no attribute '__contains__'

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• What is Inversion of control and why we need it?

  - by Jalpesh P. Vadgama

  Most of programmer need inversion of control pattern in today’s complex real time application world. So I have decided to write a blog post about it. This blog post will explain what is Inversion of control and why we need it. We are going to take a real world example so it would be better to understand. The problem- Why we need inversion of control? Before giving definition of Inversion of control let’s take a simple real word example to see why we need inversion of control. Please have look on the following code. public class class1 { private class2 _class2; public class1() { _class2=new class2(); } } public class class2 { //Some implementation of class2 } I have two classes “Class1” and “Class2”.  If you see the code in that I have created a instance of class2 class in the class1 class constructor. So the “class1” class is dependent on “class2”. I think that is the biggest issue in real world scenario as if we change the “class2” class then we might need to change the “class1” class also. Here there is one type of dependency between this two classes that is called Tight Coupling. Tight coupling will have lots of problem in real world applications as things are tends to be change in future so we have to change all the tight couple classes that are dependent of each other. To avoid this kind of issue we need Inversion of control. What is Inversion of Control? According to the wikipedia following is a definition of Inversion of control. “In software engineering, Inversion of Control (IoC) is an object-oriented programming practice where the object coupling is bound at run time by an assembler object and is typically not known at compile time using static analysis.” So if you read the it carefully it says that we should have object coupling at run time not compile time where it know what object it will create, what method it will call or what feature it will going to use for that. We need to use same classes in such way so that it will not tight couple with each other. There are multiple way to implement Inversion of control. You can refer wikipedia link for knowing multiple ways of implementing Inversion of control. In future posts we are going to see all the different way of implementing Inversion of control.

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• Resources such as libraries, engines and frameworks to make Javacript-based MMORTS? [closed]

  - by hhh

  I am looking for resources outlined to make a MMORTS with Javascript as the client-side, probably just a simple canvas for the frontend. The guy in the video here mentions that JavaScript is one of the most misunderstood language -- and I do believe that. I think one can make quite cool games with it in the future. So I am now proactively looking for resources and perhaps some ideas. My first idea contained Node.js, C and NetBSD/bozohttpd (or the-4-7-chars' *ix-thing with green-logo -thing, move the q here) but I acknowledge my beginner -style approach -- this issue is broad and not only for one person to make it all-the-time-improved project! So I think perfect for community to tinker. Some games and examples possibly easy to make into MMORTS BrowserQuest here under MPL 2.0 and its content licensed under CC-BY-SA 3.0 (source here) [proprietary] LoU here and built with JS/Qooxdoo/c#/Windows-Server/ISS/etc, source. MY ANSWER BEGINS HERE TO BE MOVED BELOW, REQUIRING RE-OPENING. PLEASE, VOTE TO OPEN IT -- HELP US TO TINKER! My answer Generic Is there an MMO-related research body? Although about Android, certain things also appropriate with JS -game: Are there any 2D gaming libraries/frameworks/engines for Android? Why is it so hard to develop a MMO? Browser based MMO Architecture MMO architecture - Highly Scalable with Reporting capabilities What are the Elements of an MMO Game? Is this the right architecture for our MMORPG mobile game? Looking for architectures to develop massive multiplayer game server Information on seamless MMO server architecture Game-mechanics (search) Question sounding like about LoU: What are the different ways to balance an online multiplayer game where user spend different amounts of time online? Building an instance system What are the different ways to balance an online multiplayer game where user spend different amounts of time online? Hosting is it possible to make a MMO starting with scalable hosting? Should I keep login server apart from game server? MMO techniques, algorithms and resources for keeping bandwidth low? MMO Proxy Server Javascript and Client-based things What do I need to do a MMORTS in JavaScript with small amount of Developers? How to update the monsters in my MMO server using Node.js and Socket.IO Are there any good html 5 mmo design tutorials? Networking Loadbalancing Questions Something about TCP, routers, NAT, etc: How do I start writing an MMO game server? Who does the AI calculations in an MMO? They need someone more knowledgable to work with, a lot of cases where the same words mean different things. Data Structures What data structure should I use for a Diablo/WoW-style talent tree? Game Engine Need an engine for MMO mockup Helper sites http://www.gamedev.net/page/index.html

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• What’s new in Silverlight 4 RC?

  - by pluginbaby

  I am here in Las Vegas for MIX10 where Scott Guthrie announced today the release of Silverlight 4 RC and the Visual Studio 2010 tools. You can now install VS2010 RC!!! As always, downloads links are here: www.silverlight.net He also said that the final version of Silverlight 4 will come next month (so april)! 4 months ago, I wrote a blog post on the new features of Silverlight 4 beta, so… what’s new in the RC ?   Rich Text · RichTextArea renamed to RichTextBox · Text position and selection APIs · “Xaml” property for serializing text content · XAML clipboard format · FlowDirection support on Runs tag · “Format then type” support when dragging controls to the designer · Thai/Vietnamese/Indic support · UI Automation Text pattern   Networking · UploadProgress support (Client stack) · Caching support (Client stack) · Sockets security restrictions removal (Elevated Trust) · Sockets policy file retrieval via HTTP · Accept-Language header   Out of Browser (Elevated Trust) · XAP signing · Silent install and emulation mode · Custom window chrome · Better support for COM Automation · Cancellable shutdown event · Updated security dialogs   Media · Pinned full-screen mode on secondary display · Webcam/Mic configuration preview · More descriptive MediaSourceStream errors · Content & Output protection updates · Updates to H.264 content protection (ClearNAL) · Digital Constraint Token · CGMS-A · Multicast · Graphics card driver validation & revocation   Graphics and Printing · HW accelerated Perspective Transforms · Ability to query page size and printable area · Memory usage and perf improvements   Data · Entity-level validation support of INotifyDataErrorInfo for DataGrid · XPath support for XML   Parser · New architecture enables future innovation · Performance and stability improvements · XmlnsPrefix & XmlnsDefinition attributes · Support setting order-dependent properties   Globalization & Localization · Support for 31 new languages · Arabic, Hebrew and Thai input on Mac · Indic support   More … · Update to DeepZoom code base with HW acceleration · Support for Private mode browsing · Google Chrome support (Windows) · FrameworkElement.Unloaded event · HTML Hosting accessibility · IsoStore perf improvements · Native hosting perf improvements (e.g., Bing Toolbar) · Consistency with Silverlight for Mobile APIs and Tooling · SDK   - System.Numerics.dll   - Dynamic XAP support (MEF)   - Frame/Navigation refresh support   That’s a lot!   You will find more details on the following links: http://timheuer.com/blog/archive/2010/03/15/whats-new-in-silverlight-4-rc-mix10.aspx http://www.davidpoll.com/2010/03/15/new-in-the-silverlight-4-rc-xaml-features/   Technorati Tags: Silverlight

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• Passthrough Objects – Duck Typing++

  - by EltonStoneman

  [Source: http://geekswithblogs.net/EltonStoneman] Can't see a genuine use for this, but I got the idea in my head and wanted to work it through. It's an extension to the idea of duck typing, for scenarios where types have similar behaviour, but implemented in differently-named members. So you may have a set of objects you want to treat as an interface, which don't implement the interface explicitly, and don't have the same member names so they can't be duck-typed into implicitly implementing the interface. In a fictitious example, I want to call Get on whichever ICache implementation is current, and have the call passed through to the relevant method – whether it's called Read, Retrieve or whatever: A sample implementation is up on github here: PassthroughSample. This uses Castle's DynamicProxy behind the scenes in the same way as my duck typing sample, but allows you to configure the passthrough to specify how the inner (implementation) and outer (interface) members are mapped:       var setup = new Passthrough();     var cache = setup.Create("PassthroughSample.Tests.Stubs.AspNetCache, PassthroughSample.Tests")                             .WithPassthrough("Name", "CacheName")                             .WithPassthrough("Get", "Retrieve")                             .WithPassthrough("Set", "Insert")                             .As<ICache>(); - or using some ugly Lambdas to avoid the strings :     Expression<Func<ICache, string, object>> get = (o, s) => o.Get(s);     Expression<Func<Memcached, string, object>> read = (i, s) => i.Read(s);     Expression<Action<ICache, string, object>> set = (o, s, obj) => o.Set(s, obj);     Expression<Action<Memcached, string, object>> insert = (i, s, obj) => i.Put(s, obj);       ICache cache = new Passthrough<ICache, Memcached>()                     .Create()                     .WithPassthrough(o => o.Name, i => i.InstanceName)                     .WithPassthrough(get, read)                     .WithPassthrough(set, insert)                     .As();   - or even in config:   ICache cache = Passthrough.GetConfigured<ICache>(); ...  <passthrough>     <types>       <typename="PassthroughSample.Tests.Stubs.ICache, PassthroughSample.Tests"             passesThroughTo="PassthroughSample.Tests.Stubs.AppFabricCache, PassthroughSample.Tests">         <members>           <membername="Name"passesThroughTo="RegionName"/>           <membername="Get"passesThroughTo="Out"/>           <membername="Set"passesThroughTo="In"/>         </members>       </type>   Possibly useful for injecting stubs for dependencies in tests, when your application code isn't using an IoC container. Possibly it also has an alternative implementation using .NET 4.0 dynamic objects, rather than the dynamic proxy.

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• Developing Spring Portlet for use inside Weblogic Portal / Webcenter Portal

  - by Murali Veligeti

  We need to understand the main difference between portlet workflow and servlet workflow.The main difference between portlet workflow and servlet workflow is that, the request to the portlet can have two distinct phases: 1) Action phase 2) Render phase. The Action phase is executed only once and is where any 'backend' changes or actions occur, such as making changes in a database. The Render phase then produces what is displayed to the user each time the display is refreshed. The critical point here is that for a single overall request, the action phase is executed only once, but the render phase may be executed multiple times. This provides a clean separation between the activities that modify the persistent state of your system and the activities that generate what is displayed to the user.The dual phases of portlet requests are one of the real strengths of the JSR-168 specification. For example, dynamic search results can be updated routinely on the display without the user explicitly re-running the search. Most other portlet MVC frameworks attempt to completely hide the two phases from the developer and make it look as much like traditional servlet development as possible - we think this approach removes one of the main benefits of using portlets. So, the separation of the two phases is preserved throughout the Spring Portlet MVC framework. The primary manifestation of this approach is that where the servlet version of the MVC classes will have one method that deals with the request, the portlet version of the MVC classes will have two methods that deal with the request: one for the action phase and one for the render phase. For example, where the servlet version of AbstractController has the handleRequestInternal(..) method, the portlet version of AbstractController has handleActionRequestInternal(..) and handleRenderRequestInternal(..) methods.The Spring Portlet Framework is designed around a DispatcherPortlet that dispatches requests to handlers, with configurable handler mappings and view resolution, just as the DispatcherServlet in the Spring Web Framework does.  Developing portlet.xml Let's start the sample development by creating the portlet.xml file in the /WebContent/WEB-INF/ folder as shown below: <?xml version="1.0" encoding="UTF-8"?> <portlet-app version="2.0" xmlns="http://java.sun.com/xml/ns/portlet/portlet-app_2_0.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <portlet> <portlet-name>SpringPortletName</portlet-name> <portlet-class>org.springframework.web.portlet.DispatcherPortlet</portlet-class> <supports> <mime-type>text/html</mime-type> <portlet-mode>view</portlet-mode> </supports> <portlet-info> <title>SpringPortlet</title> </portlet-info> </portlet> </portlet-app> DispatcherPortlet is responsible for handling every client request. When it receives a request, it finds out which Controller class should be used for handling this request, and then it calls its handleActionRequest() or handleRenderRequest() method based on the request processing phase. The Controller class executes business logic and returns a View name that should be used for rendering markup to the user. The DispatcherPortlet then forwards control to that View for actual markup generation. As you can see, DispatcherPortlet is the central dispatcher for use within Spring Portlet MVC Framework. Note that your portlet application can define more than one DispatcherPortlet. If it does so, then each of these portlets operates its own namespace, loading its application context and handler mapping. The DispatcherPortlet is also responsible for loading application context (Spring configuration file) for this portlet. First, it tries to check the value of the configLocation portlet initialization parameter. If that parameter is not specified, it takes the portlet name (that is, the value of the <portlet-name> element), appends "-portlet.xml" to it, and tries to load that file from the /WEB-INF folder. In the portlet.xml file, we did not specify the configLocation initialization parameter, so let's create SpringPortletName-portlet.xml file in the next section. Developing SpringPortletName-portlet.xml Create the SpringPortletName-portlet.xml file in the /WebContent/WEB-INF folder of your application as shown below: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd"> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/> <property name="prefix" value="/jsp/"/> <property name="suffix" value=".jsp"/> </bean> <bean id="pointManager" class="com.wlp.spring.bo.internal.PointManagerImpl"> <property name="users"> <list> <ref bean="point1"/> <ref bean="point2"/> <ref bean="point3"/> <ref bean="point4"/> </list> </property> </bean> <bean id="point1" class="com.wlp.spring.bean.User"> <property name="name" value="Murali"/> <property name="points" value="6"/> </bean> <bean id="point2" class="com.wlp.spring.bean.User"> <property name="name" value="Sai"/> <property name="points" value="13"/> </bean> <bean id="point3" class="com.wlp.spring.bean.User"> <property name="name" value="Rama"/> <property name="points" value="43"/> </bean> <bean id="point4" class="com.wlp.spring.bean.User"> <property name="name" value="Krishna"/> <property name="points" value="23"/> </bean> <bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource"> <property name="basename" value="messages"/> </bean> <bean name="/users.htm" id="userController" class="com.wlp.spring.controller.UserController"> <property name="pointManager" ref="pointManager"/> </bean> <bean name="/pointincrease.htm" id="pointIncreaseController" class="com.wlp.spring.controller.IncreasePointsFormController"> <property name="sessionForm" value="true"/> <property name="pointManager" ref="pointManager"/> <property name="commandName" value="pointIncrease"/> <property name="commandClass" value="com.wlp.spring.bean.PointIncrease"/> <property name="formView" value="pointincrease"/> <property name="successView" value="users"/> </bean> <bean id="parameterMappingInterceptor" class="org.springframework.web.portlet.handler.ParameterMappingInterceptor" /> <bean id="portletModeParameterHandlerMapping" class="org.springframework.web.portlet.handler.PortletModeParameterHandlerMapping"> <property name="order" value="1" /> <property name="interceptors"> <list> <ref bean="parameterMappingInterceptor" /> </list> </property> <property name="portletModeParameterMap"> <map> <entry key="view"> <map> <entry key="pointincrease"> <ref bean="pointIncreaseController" /> </entry> <entry key="users"> <ref bean="userController" /> </entry> </map> </entry> </map> </property> </bean> <bean id="portletModeHandlerMapping" class="org.springframework.web.portlet.handler.PortletModeHandlerMapping"> <property name="order" value="2" /> <property name="portletModeMap"> <map> <entry key="view"> <ref bean="userController" /> </entry> </map> </property> </bean> </beans> The SpringPortletName-portlet.xml file is an application context file for your MVC portlet. It has a couple of bean definitions: viewController. At this point, remember that the viewController bean definition points to the com.ibm.developerworks.springmvc.ViewController.java class. portletModeHandlerMapping. As we discussed in the last section, whenever DispatcherPortlet gets a client request, it tries to find a suitable Controller class for handling that request. That is where PortletModeHandlerMapping comes into the picture. The PortletModeHandlerMapping class is a simple implementation of the HandlerMapping interface and is used by DispatcherPortlet to find a suitable Controller for every request. The PortletModeHandlerMapping class uses Portlet mode for the current request to find a suitable Controller class to use for handling the request. The portletModeMap property of portletModeHandlerMapping bean is the place where we map the Portlet mode name against the Controller class. In the sample code, we show that viewController is responsible for handling View mode requests. Developing UserController.java In the preceding section, you learned that the viewController bean is responsible for handling all the View mode requests. Your next step is to create the UserController.java class as shown below: public class UserController extends AbstractController { private PointManager pointManager; public void handleActionRequest(ActionRequest request, ActionResponse response) throws Exception { } public ModelAndView handleRenderRequest(RenderRequest request, RenderResponse response) throws ServletException, IOException { String now = (new java.util.Date()).toString(); Map<String, Object> myModel = new HashMap<String, Object>(); myModel.put("now", now); myModel.put("users", this.pointManager.getUsers()); return new ModelAndView("users", "model", myModel); } public void setPointManager(PointManager pointManager) { this.pointManager = pointManager; } } Every controller class in Spring Portlet MVC Framework must implement the org.springframework.web. portlet.mvc.Controller interface directly or indirectly. To make things easier, Spring Framework provides AbstractController class, which is the default implementation of the Controller interface. As a developer, you should always extend your controller from either AbstractController or one of its more specific subclasses. Any implementation of the Controller class should be reusable, thread-safe, and capable of handling multiple requests throughout the lifecycle of the portlet. In the sample code, we create the ViewController class by extending it from AbstractController. Because we don't want to do any action processing in the HelloSpringPortletMVC portlet, we override only the handleRenderRequest() method of AbstractController. Now, the only thing that HelloWorldPortletMVC should do is render the markup of View.jsp to the user when it receives a user request to do so. To do that, return the object of ModelAndView with a value of view equal to View. Developing web.xml According to Portlet Specification 1.0, every portlet application is also a Servlet Specification 2.3-compliant Web application, and it needs a Web application deployment descriptor (that is, web.xml). Let’s create the web.xml file in the /WEB-INF/ folder as shown in listing 4. Follow these steps: Open the existing web.xml file located at /WebContent/WEB-INF/web.xml. Replace the contents of this file with the code as shown below: <servlet> <servlet-name>ViewRendererServlet</servlet-name> <servlet-class>org.springframework.web.servlet.ViewRendererServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>ViewRendererServlet</servlet-name> <url-pattern>/WEB-INF/servlet/view</url-pattern> </servlet-mapping> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/applicationContext.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> The web.xml file for the sample portlet declares two things: ViewRendererServlet. The ViewRendererServlet is the bridge servlet for portlet support. During the render phase, DispatcherPortlet wraps PortletRequest into ServletRequest and forwards control to ViewRendererServlet for actual rendering. This process allows Spring Portlet MVC Framework to use the same View infrastructure as that of its servlet version, that is, Spring Web MVC Framework. ContextLoaderListener. The ContextLoaderListener class takes care of loading Web application context at the time of the Web application startup. The Web application context is shared by all the portlets in the portlet application. In case of duplicate bean definition, the bean definition in the portlet application context takes precedence over the Web application context. The ContextLoader class tries to read the value of the contextConfigLocation Web context parameter to find out the location of the context file. If the contextConfigLocation parameter is not set, then it uses the default value, which is /WEB-INF/applicationContext.xml, to load the context file. The Portlet Controller interface requires two methods that handle the two phases of a portlet request: the action request and the render request. The action phase should be capable of handling an action request and the render phase should be capable of handling a render request and returning an appropriate model and view. While the Controller interface is quite abstract, Spring Portlet MVC offers a lot of controllers that already contain a lot of the functionality you might need – most of these are very similar to controllers from Spring Web MVC. The Controller interface just defines the most common functionality required of every controller - handling an action request, handling a render request, and returning a model and a view. How rendering works As you know, when the user tries to access a page with PointSystemPortletMVC portlet on it or when the user performs some action on any other portlet on that page or tries to refresh that page, a render request is sent to the PointSystemPortletMVC portlet. In the sample code, because DispatcherPortlet is the main portlet class, Weblogic Portal / Webcenter Portal calls its render() method and then the following sequence of events occurs: The render() method of DispatcherPortlet calls the doDispatch() method, which in turn calls the doRender() method. After the doRenderService() method gets control, first it tries to find out the locale of the request by calling the PortletRequest.getLocale() method. This locale is used while making all the locale-related decisions for choices such as which resource bundle should be loaded or which JSP should be displayed to the user based on the locale. After that, the doRenderService() method starts iterating through all the HandlerMapping classes configured for this portlet, calling their getHandler() method to identify the appropriate Controller for handling this request. In the sample code, we have configured only PortletModeHandlerMapping as a HandlerMapping class. The PortletModeHandlerMapping class reads the value of the current portlet mode, and based on that, it finds out, the Controller class that should be used to handle this request. In the sample code, ViewController is configured to handle the View mode request so that the PortletModeHandlerMapping class returns the object of ViewController. After the object of ViewController is returned, the doRenderService() method calls its handleRenderRequestInternal() method. Implementation of the handleRenderRequestInternal() method in ViewController.java is very simple. It logs a message saying that it got control, and then it creates an instance of ModelAndView with a value equal to View and returns it to DispatcherPortlet. After control returns to doRenderService(), the next task is to figure out how to render View. For that, DispatcherPortlet starts iterating through all the ViewResolvers configured in your portlet application, calling their resolveViewName() method. In the sample code we have configured only one ViewResolver, InternalResourceViewResolver. When its resolveViewName() method is called with viewName, it tries to add /WEB-INF/jsp as a prefix to the view name and to add JSP as a suffix. And it checks if /WEB-INF/jsp/View.jsp exists. If it does exist, it returns the object of JstlView wrapping View.jsp. After control is returned to the doRenderService() method, it creates the object PortletRequestDispatcher, which points to /WEB-INF/servlet/view – that is, ViewRendererServlet. Then it sets the object of JstlView in the request and dispatches the request to ViewRendererServlet. After ViewRendererServlet gets control, it reads the JstlView object from the request attribute and creates another RequestDispatcher pointing to the /WEB-INF/jsp/View.jsp URL and passes control to it for actual markup generation. The markup generated by View.jsp is returned to user. At this point, you may question the need for ViewRendererServlet. Why can't DispatcherPortlet directly forward control to View.jsp? Adding ViewRendererServlet in between allows Spring Portlet MVC Framework to reuse the existing View infrastructure. You may appreciate this more when we discuss how easy it is to integrate Apache Tiles Framework with your Spring Portlet MVC Framework. The attached project SpringPortlet.zip should be used to import the project in to your OEPE Workspace. SpringPortlet_Jars.zip contains jar files required for the application. Project is written on Spring 2.5.  The same JSR 168 portlet should work on Webcenter Portal as well.  Downloads: Download WeblogicPotal Project which consists of Spring Portlet. Download Spring Jars In-addition to above you need to download Spring.jar (Spring2.5)

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• Friday Fun: Factory Balls – Christmas Edition

  - by Asian Angel

  Your weekend is almost here, but until the work day is over we have another fun holiday game for you. This week your job is to correctly decorate/paint the ornaments that go on the Christmas tree. Simple you say? Maybe, but maybe not! Factory Balls – Christmas Edition The object of the game is to correctly decorate/paint each Christmas ornament exactly as shown in the “sample image” provided for each level. What starts off as simple will quickly have you working to figure out the correct combination or sequence to complete each ornament. Are you ready? The first level serves as a tutorial to help you become comfortable with how to decorate/paint the ornaments. To move an ornament to a paint bucket or cover part of it with one of the helper items simply drag the ornament towards that area. The ornament will automatically move back to its’ starting position when the action is complete. First, a nice coat of red paint followed by covering the middle area with a horizontal belt. Once the belt is on move the ornament to the bucket of yellow paint. Next, you will need to remove the belt, so move the ornament back to the belt’s original position. One ornament finished! As soon as you complete decorating/painting an ornament, you move on to the next level and will be shown the next “sample Image” in the upper right corner. Starting with a coat of orange paint sounds good… Pop the little serrated edge cap on top… Add some blue paint… Almost have it… Place the large serrated edge cap on top… Another dip in the orange paint… And the second ornament is finished. Level three looks a little bit tougher…just work out your pattern of helper items & colors and you will definitely get it! Have fun decorating/painting those ornaments! Note: Starting with level four you will need to start using a combination of two helper items combined at times to properly complete the ornaments. Play Factory Balls – Christmas Edition Latest Features How-To Geek ETC The Complete List of iPad Tips, Tricks, and Tutorials The 50 Best Registry Hacks that Make Windows Better The How-To Geek Holiday Gift Guide (Geeky Stuff We Like) LCD? LED? Plasma? The How-To Geek Guide to HDTV Technology The How-To Geek Guide to Learning Photoshop, Part 8: Filters Improve Digital Photography by Calibrating Your Monitor Exploring the Jungle Ruins Wallpaper Protect Your Privacy When Browsing with Chrome and Iron Browser Free Shipping Day is Friday, December 17, 2010 – National Free Shipping Day Find an Applicable Quote for Any Programming Situation Winter Theme for Windows 7 from Microsoft Score Free In-Flight Wi-Fi Courtesy of Google Chrome

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• Dependency injection with n-tier Entity Framework solution

  - by Matthew

  I am currently designing an n-tier solution which is using Entity Framework 5 (.net 4) as its data access strategy, but am concerned about how to incorporate dependency injection to make it testable / flexible. My current solution layout is as follows (my solution is called Alcatraz): Alcatraz.WebUI: An asp.net webform project, the front end user interface, references projects Alcatraz.Business and Alcatraz.Data.Models. Alcatraz.Business: A class library project, contains the business logic, references projects Alcatraz.Data.Access, Alcatraz.Data.Models Alcatraz.Data.Access: A class library project, houses AlcatrazModel.edmx and AlcatrazEntities DbContext, references projects Alcatraz.Data.Models. Alcatraz.Data.Models: A class library project, contains POCOs for the Alcatraz model, no references. My vision for how this solution would work is the web-ui would instantiate a repository within the business library, this repository would have a dependency (through the constructor) of a connection string (not an AlcatrazEntities instance). The web-ui would know the database connection strings, but not that it was an entity framework connection string. In the Business project: public class InmateRepository : IInmateRepository { private string _connectionString; public InmateRepository(string connectionString) { if (connectionString == null) { throw new ArgumentNullException("connectionString"); } EntityConnectionStringBuilder connectionBuilder = new EntityConnectionStringBuilder(); connectionBuilder.Metadata = "res://*/AlcatrazModel.csdl|res://*/AlcatrazModel.ssdl|res://*/AlcatrazModel.msl"; connectionBuilder.Provider = "System.Data.SqlClient"; connectionBuilder.ProviderConnectionString = connectionString; _connectionString = connectionBuilder.ToString(); } public IQueryable<Inmate> GetAllInmates() { AlcatrazEntities ents = new AlcatrazEntities(_connectionString); return ents.Inmates; } } In the Web UI: IInmateRepository inmateRepo = new InmateRepository(@"data source=MATTHEW-PC\SQLEXPRESS;initial catalog=Alcatraz;integrated security=True;"); List<Inmate> deathRowInmates = inmateRepo.GetAllInmates().Where(i => i.OnDeathRow).ToList(); I have a few related questions about this design. 1) Does this design even make sense in terms of Entity Frameworks capabilities? I heard that Entity framework uses the Unit-of-work pattern already, am I just adding another layer of abstract unnecessarily? 2) I don't want my web-ui to directly communicate with Entity Framework (or even reference it for that matter), I want all database access to go through the business layer as in the future I will have multiple projects using the same business layer (web service, windows application, etc.) and I want to have it easy to maintain / update by having the business logic in one central area. Is this an appropriate way to achieve this? 3) Should the Business layer even contain repositories, or should that be contained within the Access layer? If where they are is alright, is passing a connection string a good dependency to assume? Thanks for taking the time to read!

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• Up in the Air: Team Oracle Play-by-Play

  - by Aaron Lazenby

  Yesterday, I had the amazing opportunity to fly along with Sean D. Tucker and Team Oracle. Leaving from the San Carols airport, we did a 30 minute flight over the Pacific just south of the coastal town of Half Moon Bay. In that half hour, I rode through a massive 4G loop, survived a crushing hammerhead, and took control of the plane to perform a basic wing over (you can learn what the heck I'm talking about by visiting this website). I have lots of great video, but it's going to take me some time to make sense of it. For now, here's my Twitter-based play-by-play of yesterday's events. Many thanks to Sean D. Tucker and the whole crew (Ben and Ian, especially) for this great opportunity to fly with Team Oracle.Live tweets from @OracleProfitI will be spending the afternoon in a stunt plane, upside down above the San Francisco bay. http://bit.ly/cwkrkIAt the San Carlos airport. More than slightly freaked out. Shaking hands diminish texting ability. Slightly reassuring. http://yfrog.com/1qt61nj There go the doors to the photo plane... #teamoracle http://yfrog.com/58ywljSean D Tucker assures me: "The sky is a great place to be." Helpful, but I'm still nervous. #teamoracle"You get a parachute. He gets a harness." How was this decision made? #teamoracleThe plane with @radu43 has returned. I'm up next...Couldn't help myself...drank a soda before flying. Mistake? We'll see... #teamoracleAdvice of the day "If you pull with two hands, you improve the chances of the chute deploying on the first try." Lovely. #teamoracleI feel so strange. But I flew a high performance airplane. And did an aerobatics move. Wild. #teamoracle"Flying ten feet off he ground, upside-down at 250 miles per hour isn't exciting to me." Sean D. Tucker #teamoracle"What is exciting to me is flying that perfect pattern, just like I imagined it in my head." Sean D. Tucker #teamoracle"You're going to sleep well tonight. You just carried four times your body weight." #teamoracle #gforce Just watched the #teamoracle plane take off for its flight home. I'm waiting for Caltrain. #undignifiedanticlimaxEnough with the #teamoracle. Check http://blogs.oracle.com/profit for the video. Coming soon! 

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• E 2.0 Value Metaphors

  - by Tom Tonkin

  I guess I have been doing this too long. I can easily see the value of Enterprise 2.0 technology for an organization, but find it a challenge at times to convey that same value to others. I also know that I'm not the only one that has that issue. Others, that have that same passion, also suffer from being, perhaps, too close to the market. I was having this same discussion with a few colleagues when one of them suggested that metaphors might be a good vehicle to communicate the value to those that are not as familiar.  One such metaphor was discussed.Apparently,back in the early 50's, there was a great Air Force aviator and military strategist by the name of John Boyd.  Without going into a ton of detail (you can search him on the internet), what made Colonel Boyd great was that he never lost a dog fight.  As a matter of fact, they called him 'Forty-Second Boyd' since he claimed to be able to beat anyone in any type of aircraft in less than forty seconds, even if his aircraft was inferior to his opponents.His approach as was unique.  He observed over time that there was a pattern on how aviators  engaged in a dogfight.  He called this method OODA.   It describes how a person or, in our case, an organization, would react to an event.  OODA is an acrostic for Observation, Orientation, Decision and Action.  Again, there is a lot more on the internet about this.A pilot would go through this loop several times during a dogfight and Boyd would try to predict this loop and interrupt it by changing the landscape of the actual dogfight.  This would give Boyd an advantage and be able to predict what his opponent would do and then counterattack.Boyd went on to say that many companies have a similar reaction loop and that by understanding that loop, organizations would be able to adjust better to market conditions, predict what the competition is doing and reposition themselves to gain competitive advantages. So, our metaphor would be that Enterprise 2.0 provides companies greater visibility of their business by connecting to employees, customers and partners in a collaborative fashion.  This, in turn, helps them navigate through the tough times and provide lines of sight to more innovative ideas.  Innovation is that last tool for companies to achieve competitive advantage (maybe a discusion for another post).Perhaps this is more wordy than some other metaphor, but it does allow for an interesting  dialogue to start and maybe even a framwork to fullfill the promise of E 2.0. So, I'm sure there are many more metaphors for the value that E 2.0 brings to organzaitons. Do you have one to share? Please comment below and thanks for stopping by.

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• Silverlight Cream for March 11, 2010 -- #812

  - by Dave Campbell

  In this Issue: Walter Ferrari, Viktor Larsson, Bill Reiss(-2-, -3-, -4-), Jonathan van de Veen, Walt Ritscher, Jobi Joy, Pete Brown, Mike Taulty, and Mark Miller. Shoutouts: Going to MIX10? John Papa announced Got Questions? Ask the Experts at MIX10 Pete Brown listed The Essential WPF/Silverlight/XNA Developer and Designer Toolbox From SilverlightCream.com: How to extend Bing Maps Silverlight with an elevation profile graph - Part 2 In this second and final tutorial, Walter Ferrari adds elevation to his previous BingMaps post. I'm glad someone else worked this out for me :) Navigating AWAY from your Silverlight page Viktor Larsson has a post up on how to navigate to something other than your Silverlight page like maybe a mailto ... SilverSprite: Not just for XNA games any more Bill Reiss has a new version of SilverSprite up on CodePlex and if you're planning on doing any game development, you should check this out for sure Space Rocks game step 1: The game loop Bill Reiss has a tutorial series on Game development that he's beginning ... looks like a good thing to jump in on and play along. This first one is all about the game loop. Space Rocks game step 2: Sprites (part 1) In Part 2, Bill Reiss begins a series on Sprites in game development and positioning it. Space Rocks game step 3: Sprites (part 2) Bill Reiss's Part 3 is a follow-on tutorial on Sprites and moving according to velocity... fun stuff :) Adventures while building a Silverlight Enterprise application part No. 32 Jonathan van de Veen is discussing debugging and the evil you can get yourself wrapped up in... his scenario is definitely one to remember. Streaming Silverlight media from a Dropbox.com account Read the comments and the agreements, but I think Walt Ritscher's idea of using DropBox to serve up Streaming media is pretty cool! UniformGrid for Silverlight Jobi Joy wanted a UniformGrid like he's familiar with in WPF. Not finding one in the SDK or Toolkit, he converted the WPF one to Silverlight .. all good for you and me :) How to Get Started in WPF or Silverlight: A Learning Path for New Developers Pete Brown has a nice post up describing resources, tutorials, blogs, and books for devs just getting into Silveright or WPF, and thanks for the shoutout, Pete! Silverlight 4, MEF and the DeploymentCatalog ( again :-) ) Mike Taulty is revisiting the DeploymentCatalog to wrap it up in a class like he did the PackageCatalog previously MVVM with Prism 101 – Part 6b: Wrapping IClientChannel Mark Miller is back with a Part 6b on MVVM with Prism, and is answering some questions from the previous post and states his case against the client service proxy. Stay in the 'Light! Twitter SilverlightNews | Twitter WynApse | WynApse.com | Tagged Posts | SilverlightCream Join me @ SilverlightCream | Phoenix Silverlight User Group Technorati Tags: Silverlight    Silverlight 3    Silverlight 4    MIX10

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• Scaling-out Your Services by Message Bus based WCF Transport Extension &ndash; Part 1 &ndash; Background

  - by Shaun

  Cloud computing gives us more flexibility on the computing resource, we can provision and deploy an application or service with multiple instances over multiple machines. With the increment of the service instances, how to balance the incoming message and workload would become a new challenge. Currently there are two approaches we can use to pass the incoming messages to the service instances, I would like call them dispatcher mode and pulling mode.   Dispatcher Mode The dispatcher mode introduces a role which takes the responsible to find the best service instance to process the request. The image below describes the sharp of this mode. There are four clients communicate with the service through the underlying transportation. For example, if we are using HTTP the clients might be connecting to the same service URL. On the server side there’s a dispatcher listening on this URL and try to retrieve all messages. When a message came in, the dispatcher will find a proper service instance to process it. There are three mechanism to find the instance: Round-robin: Dispatcher will always send the message to the next instance. For example, if the dispatcher sent the message to instance 2, then the next message will be sent to instance 3, regardless if instance 3 is busy or not at that moment. Random: Dispatcher will find a service instance randomly, and same as the round-robin mode it regardless if the instance is busy or not. Sticky: Dispatcher will send all related messages to the same service instance. This approach always being used if the service methods are state-ful or session-ful. But as you can see, all of these approaches are not really load balanced. The clients will send messages at any time, and each message might take different process duration on the server side. This means in some cases, some of the service instances are very busy while others are almost idle. For example, if we were using round-robin mode, it could be happened that most of the simple task messages were passed to instance 1 while the complex ones were sent to instance 3, even though instance 1 should be idle. This brings some problem in our architecture. The first one is that, the response to the clients might be longer than it should be. As it’s shown in the figure above, message 6 and 9 can be processed by instance 1 or instance 2, but in reality they were dispatched to the busy instance 3 since the dispatcher and round-robin mode. Secondly, if there are many requests came from the clients in a very short period, service instances might be filled by tons of pending tasks and some instances might be crashed. Third, if we are using some cloud platform to host our service instances, for example the Windows Azure, the computing resource is billed by service deployment period instead of the actual CPU usage. This means if any service instance is idle it is wasting our money! Last one, the dispatcher would be the bottleneck of our system since all incoming messages must be routed by the dispatcher. If we are using HTTP or TCP as the transport, the dispatcher would be a network load balance. If we wants more capacity, we have to scale-up, or buy a hardware load balance which is very expensive, as well as scaling-out the service instances. Pulling Mode Pulling mode doesn’t need a dispatcher to route the messages. All service instances are listening to the same transport and try to retrieve the next proper message to process if they are idle. Since there is no dispatcher in pulling mode, it requires some features on the transportation. The transportation must support multiple client connection and server listening. HTTP and TCP doesn’t allow multiple clients are listening on the same address and port, so it cannot be used in pulling mode directly. All messages in the transportation must be FIFO, which means the old message must be received before the new one. Message selection would be a plus on the transportation. This means both service and client can specify some selection criteria and just receive some specified kinds of messages. This feature is not mandatory but would be very useful when implementing the request reply and duplex WCF channel modes. Otherwise we must have a memory dictionary to store the reply messages. I will explain more about this in the following articles. Message bus, or the message queue would be best candidate as the transportation when using the pulling mode. First, it allows multiple application to listen on the same queue, and it’s FIFO. Some of the message bus also support the message selection, such as TIBCO EMS, RabbitMQ. Some others provide in memory dictionary which can store the reply messages, for example the Redis. The principle of pulling mode is to let the service instances self-managed. This means each instance will try to retrieve the next pending incoming message if they finished the current task. This gives us more benefit and can solve the problems we met with in the dispatcher mode. The incoming message will be received to the best instance to process, which means this will be very balanced. And it will not happen that some instances are busy while other are idle, since the idle one will retrieve more tasks to make them busy. Since all instances are try their best to be busy we can use less instances than dispatcher mode, which more cost effective. Since there’s no dispatcher in the system, there is no bottleneck. When we introduced more service instances, in dispatcher mode we have to change something to let the dispatcher know the new instances. But in pulling mode since all service instance are self-managed, there no extra change at all. If there are many incoming messages, since the message bus can queue them in the transportation, service instances would not be crashed. All above are the benefits using the pulling mode, but it will introduce some problem as well. The process tracking and debugging become more difficult. Since the service instances are self-managed, we cannot know which instance will process the message. So we need more information to support debug and track. Real-time response may not be supported. All service instances will process the next message after the current one has done, if we have some real-time request this may not be a good solution. Compare with the Pros and Cons above, the pulling mode would a better solution for the distributed system architecture. Because what we need more is the scalability, cost-effect and the self-management.   WCF and WCF Transport Extensibility Windows Communication Foundation (WCF) is a framework for building service-oriented applications. In the .NET world WCF is the best way to implement the service. In this series I’m going to demonstrate how to implement the pulling mode on top of a message bus by extending the WCF. I don’t want to deep into every related field in WCF but will highlight its transport extensibility. When we implemented an RPC foundation there are many aspects we need to deal with, for example the message encoding, encryption, authentication and message sending and receiving. In WCF, each aspect is represented by a channel. A message will be passed through all necessary channels and finally send to the underlying transportation. And on the other side the message will be received from the transport and though the same channels until the business logic. This mode is called “Channel Stack” in WCF, and the last channel in the channel stack must always be a transport channel, which takes the responsible for sending and receiving the messages. As we are going to implement the WCF over message bus and implement the pulling mode scaling-out solution, we need to create our own transport channel so that the client and service can exchange messages over our bus. Before we deep into the transport channel, let’s have a look on the message exchange patterns that WCF defines. Message exchange pattern (MEP) defines how client and service exchange the messages over the transportation. WCF defines 3 basic MEPs which are datagram, Request-Reply and Duplex. Datagram: Also known as one-way, or fire-forgot mode. The message sent from the client to the service, and no need any reply from the service. The client doesn’t care about the message result at all. Request-Reply: Very common used pattern. The client send the request message to the service and wait until the reply message comes from the service. Duplex: The client sent message to the service, when the service processing the message it can callback to the client. When callback the service would be like a client while the client would be like a service. In WCF, each MEP represent some channels associated. MEP Channels Datagram IInputChannel, IOutputChannel Request-Reply IRequestChannel, IReplyChannel Duplex IDuplexChannel And the channels are created by ChannelListener on the server side, and ChannelFactory on the client side. The ChannelListener and ChannelFactory are created by the TransportBindingElement. The TransportBindingElement is created by the Binding, which can be defined as a new binding or from a custom binding. For more information about the transport channel mode, please refer to the MSDN document. The figure below shows the transport channel objects when using the request-reply MEP. And this is the datagram MEP. And this is the duplex MEP. After investigated the WCF transport architecture, channel mode and MEP, we finally identified what we should do to extend our message bus based transport layer. They are: Binding: (Optional) Defines the channel elements in the channel stack and added our transport binding element at the bottom of the stack. But we can use the build-in CustomBinding as well. TransportBindingElement: Defines which MEP is supported in our transport and create the related ChannelListener and ChannelFactory. This also defines the scheme of the endpoint if using this transport. ChannelListener: Create the server side channel based on the MEP it’s. We can have one ChannelListener to create channels for all supported MEPs, or we can have ChannelListener for each MEP. In this series I will use the second approach. ChannelFactory: Create the client side channel based on the MEP it’s. We can have one ChannelFactory to create channels for all supported MEPs, or we can have ChannelFactory for each MEP. In this series I will use the second approach. Channels: Based on the MEPs we want to support, we need to implement the channels accordingly. For example, if we want our transport support Request-Reply mode we should implement IRequestChannel and IReplyChannel. In this series I will implement all 3 MEPs listed above one by one. Scaffold: In order to make our transport extension works we also need to implement some scaffold stuff. For example we need some classes to send and receive message though out message bus. We also need some codes to read and write the WCF message, etc.. These are not necessary but would be very useful in our example.   Message Bus There is only one thing remained before we can begin to implement our scaling-out support WCF transport, which is the message bus. As I mentioned above, the message bus must have some features to fulfill all the WCF MEPs. In my company we will be using TIBCO EMS, which is an enterprise message bus product. And I have said before we can use any message bus production if it’s satisfied with our requests. Here I would like to introduce an interface to separate the message bus from the WCF. This allows us to implement the bus operations by any kinds bus we are going to use. The interface would be like this. 1: public interface IBus : IDisposable 2: { 3: string SendRequest(string message, bool fromClient, string from, string to = null); 4:  5: void SendReply(string message, bool fromClient, string replyTo); 6:  7: BusMessage Receive(bool fromClient, string replyTo); 8: } There are only three methods for the bus interface. Let me explain one by one. The SendRequest method takes the responsible for sending the request message into the bus. The parameters description are: message: The WCF message content. fromClient: Indicates if this message was came from the client. from: The channel ID that this message was sent from. The channel ID will be generated when any kinds of channel was created, which will be explained in the following articles. to: The channel ID that this message should be received. In Request-Reply and Duplex MEP this is necessary since the reply message must be received by the channel which sent the related request message. The SendReply method takes the responsible for sending the reply message. It’s very similar as the previous one but no “from” parameter. This is because it’s no need to reply a reply message again in any MEPs. The Receive method takes the responsible for waiting for a incoming message, includes the request message and specified reply message. It returned a BusMessage object, which contains some information about the channel information. The code of the BusMessage class is 1: public class BusMessage 2: { 3: public string MessageID { get; private set; } 4: public string From { get; private set; } 5: public string ReplyTo { get; private set; } 6: public string Content { get; private set; } 7:  8: public BusMessage(string messageId, string fromChannelId, string replyToChannelId, string content) 9: { 10: MessageID = messageId; 11: From = fromChannelId; 12: ReplyTo = replyToChannelId; 13: Content = content; 14: } 15: } Now let’s implement a message bus based on the IBus interface. Since I don’t want you to buy and install the TIBCO EMS or any other message bus products, I will implement an in process memory bus. This bus is only for test and sample purpose. It can only be used if the service and client are in the same process. Very straightforward. 1: public class InProcMessageBus : IBus 2: { 3: private readonly ConcurrentDictionary<Guid, InProcMessageEntity> _queue; 4: private readonly object _lock; 5:  6: public InProcMessageBus() 7: { 8: _queue = new ConcurrentDictionary<Guid, InProcMessageEntity>(); 9: _lock = new object(); 10: } 11:  12: public string SendRequest(string message, bool fromClient, string from, string to = null) 13: { 14: var entity = new InProcMessageEntity(message, fromClient, from, to); 15: _queue.TryAdd(entity.ID, entity); 16: return entity.ID.ToString(); 17: } 18:  19: public void SendReply(string message, bool fromClient, string replyTo) 20: { 21: var entity = new InProcMessageEntity(message, fromClient, null, replyTo); 22: _queue.TryAdd(entity.ID, entity); 23: } 24:  25: public BusMessage Receive(bool fromClient, string replyTo) 26: { 27: InProcMessageEntity e = null; 28: while (true) 29: { 30: lock (_lock) 31: { 32: var entity = _queue 33: .Where(kvp => kvp.Value.FromClient == fromClient && (kvp.Value.To == replyTo || string.IsNullOrWhiteSpace(kvp.Value.To))) 34: .FirstOrDefault(); 35: if (entity.Key != Guid.Empty && entity.Value != null) 36: { 37: _queue.TryRemove(entity.Key, out e); 38: } 39: } 40: if (e == null) 41: { 42: Thread.Sleep(100); 43: } 44: else 45: { 46: return new BusMessage(e.ID.ToString(), e.From, e.To, e.Content); 47: } 48: } 49: } 50:  51: public void Dispose() 52: { 53: } 54: } The InProcMessageBus stores the messages in the objects of InProcMessageEntity, which can take some extra information beside the WCF message itself. 1: public class InProcMessageEntity 2: { 3: public Guid ID { get; set; } 4: public string Content { get; set; } 5: public bool FromClient { get; set; } 6: public string From { get; set; } 7: public string To { get; set; } 8:  9: public InProcMessageEntity() 10: : this(string.Empty, false, string.Empty, string.Empty) 11: { 12: } 13:  14: public InProcMessageEntity(string content, bool fromClient, string from, string to) 15: { 16: ID = Guid.NewGuid(); 17: Content = content; 18: FromClient = fromClient; 19: From = from; 20: To = to; 21: } 22: }   Summary OK, now I have all necessary stuff ready. The next step would be implementing our WCF message bus transport extension. In this post I described two scaling-out approaches on the service side especially if we are using the cloud platform: dispatcher mode and pulling mode. And I compared the Pros and Cons of them. Then I introduced the WCF channel stack, channel mode and the transport extension part, and identified what we should do to create our own WCF transport extension, to let our WCF services using pulling mode based on a message bus. And finally I provided some classes that need to be used in the future posts that working against an in process memory message bus, for the demonstration purpose only. In the next post I will begin to implement the transport extension step by step.   Hope this helps, Shaun All documents and related graphics, codes are provided "AS IS" without warranty of any kind. Copyright © Shaun Ziyan Xu. This work is licensed under the Creative Commons License.

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• Web application / Domain model integration using JSON capable DTOs [on hold]

  - by g-makulik

  I'm a bit confused about architectural choices for the web-applications/java/python world. For c/c++ world the available (open source) choices to implement web applications is pretty limited to zero, involving java or python the choices explode to a,- hard to sort out -, mess of available 'frameworks' and application approaches. I want to sort out a clean MVC model, where the M stands for a fully blown (POCO, POJO driven) domain model (according M.Fowler's EAA pattern) using a mature OO language (Java,C++) for implementation. The background is: I have a system with certain hardware components (that introduce system immanent active behavior) and a configuration database for system meta and HW-components configuration data (these are even usually self contained, since the HW-components are capable to persist their configuration data anyway). For realization of the configuration/status data exchange protocol with the HW-components we have chosen the Google Protobuf format, which works well for the directly wired communication with these components. This protocol is already used successfully with a Java based GUI application via TCP/IP connection to the main system controlling HW-component. This application has some drawbacks and design flaws for historical reasons. Now we want to develop an abstract model (domain model) for configuration and monitoring those HW-components, that represents a more use case oriented view to the overall system behavior. I have the feeling that a plain Java class model would fit best for this (c++ implementation seems to have too much implementation/integration overhead with viable language-bridge interfaces). Google Protobuf message definitions could still serve well to describe DTO objects used to interact with a domain model API. But integrating Google Protobuf messages client side for e.g. data binding in the current view doesn't seem to be a good choice. I'm thinking about some extra serialization features, e.g. for JSON based data exchange with the views/controllers. Most lightweight solutions seem to involve a python based presentation layer using JSON based data transfer (I'm at least not sure to be fully informed about this). Is there some lightweight (applicable for a limited ARM Linux platform) framework available, supporting such architecture to realize a web-application? UPDATE: According to my recent research and comments of colleagues I've noticed that using Java (and some JVM) might not be the preferable choice for integration with python on a limited linux system as we have (running on ARM9 with hard to discuss memory and MCU costs), but C/C++ modules would do well for this (since this forms the native interface to python extensions, doesn't it?). I can imagine to provide a domain model from an appropriate C/C++ API (though I still think it's more efforts and higher skill requirements for the involved developers to do with these languages). Still I'm searching for a good approach that supports such architecture. I'll appreciate any pointers!

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• Ubuntu software center not opening [closed]

  - by I'll sudeepdino008

  Ubuntu software center is not opening, when I type: software-center in the command line, the following errors are generated: (software-center:8570): Gtk-WARNING **: Theme parsing error: gtk.css:227:31: Failed to import: Error opening file: No such file or directory 2012-09-30 17:00:58,068 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'http://10.3.100.212:8080/' 2012-09-30 17:00:58,071 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True 2012-09-30 17:00:58,327 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file 2012-09-30 17:00:58,428 - softwarecenter.ui.gtk3.app - INFO - show_available_packages: search_text is '', app is None. 2012-09-30 17:00:58,433 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open() Traceback (most recent call last): File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 243, in open self._cache = apt.Cache(GtkMainIterationProgress()) File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 102, in __init__ self.open(progress) File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 145, in open self._cache = apt_pkg.Cache(progress) SystemError: E:Encountered a section with no Package: header, E:Problem with MergeList /var/lib/apt/lists/ppa.launchpad.net_webupd8team_themes_ubuntu_dists_precise_main_binary-i386_Packages, E:The package lists or status file could not be parsed or opened. 2012-09-30 17:01:00,130 - softwarecenter.db.enquire - ERROR - _get_estimate_nr_apps_and_nr_pkgs failed Traceback (most recent call last): File "/usr/share/software-center/softwarecenter/db/enquire.py", line 115, in _get_estimate_nr_apps_and_nr_pkgs tmp_matches = enquire.get_mset(0, len(self.db), None, xfilter) File "/usr/share/software-center/softwarecenter/db/appfilter.py", line 89, in __call__ if (not pkgname in self.cache and File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 263, in __contains__ return self._cache.__contains__(k) AttributeError: 'NoneType' object has no attribute '__contains__' Traceback (most recent call last): File "/usr/bin/software-center", line 176, in <module> app.run(args) File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1422, in run self.show_available_packages(args) File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1352, in show_available_packages self.view_manager.set_active_view(ViewPages.AVAILABLE) File "/usr/share/software-center/softwarecenter/ui/gtk3/session/viewmanager.py", line 154, in set_active_view view_widget.init_view() File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/availablepane.py", line 171, in init_view self.apps_filter) File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 238, in __init__ self.build(desktopdir) File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 511, in build self._build_homepage_view() File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 271, in _build_homepage_view self._append_whats_new() File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 450, in _append_whats_new whats_new_cat = self._update_whats_new_content() File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 439, in _update_whats_new_content docs = whats_new_cat.get_documents(self.db) File "/usr/share/software-center/softwarecenter/db/categories.py", line 124, in get_documents nonblocking_load=False) File "/usr/share/software-center/softwarecenter/db/enquire.py", line 317, in set_query self._blocking_perform_search() File "/usr/share/software-center/softwarecenter/db/enquire.py", line 212, in _blocking_perform_search matches = enquire.get_mset(0, self.limit, None, xfilter) File "/usr/share/software-center/softwarecenter/db/appfilter.py", line 89, in __call__ if (not pkgname in self.cache and File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 263, in __contains__ return self._cache.__contains__(k) AttributeError: 'NoneType' object has no attribute '__contains__'

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• I changed the repository and now my ubuntu software center crashes

  - by Paul Menz

  paul@ubuntu:~$ software-center 2012-10-24 18:11:04,665 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None' 2012-10-24 18:11:04,671 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True 2012-10-24 18:11:05,191 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file 2012-10-24 18:11:05,403 - softwarecenter.ui.gtk3.app - INFO - show_available_packages: search_text is '', app is None. 2012-10-24 18:11:05,920 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open() Traceback (most recent call last): File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 243, in open self._cache = apt.Cache(GtkMainIterationProgress()) File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 102, in __init__ self.open(progress) File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 149, in open self._list.read_main_list() SystemError: E:Malformed line 63 in source list /etc/apt/sources.list (dist parse) 2012-10-24 18:11:07,255 - softwarecenter.db.enquire - ERROR - _get_estimate_nr_apps_and_nr_pkgs failed Traceback (most recent call last): File "/usr/share/software-center/softwarecenter/db/enquire.py", line 115, in _get_estimate_nr_apps_and_nr_pkgs tmp_matches = enquire.get_mset(0, len(self.db), None, xfilter) File "/usr/share/software-center/softwarecenter/db/appfilter.py", line 89, in __call__ if (not pkgname in self.cache and File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 263, in __contains__ return self._cache.__contains__(k) AttributeError: 'NoneType' object has no attribute '__contains__' Traceback (most recent call last): File "/usr/bin/software-center", line 176, in <module> app.run(args) File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1422, in run self.show_available_packages(args) File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1352, in show_available_packages self.view_manager.set_active_view(ViewPages.AVAILABLE) File "/usr/share/software-center/softwarecenter/ui/gtk3/session/viewmanager.py", line 154, in set_active_view view_widget.init_view() File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/availablepane.py", line 171, in init_view self.apps_filter) File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 238, in __init__ self.build(desktopdir) File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 511, in build self._build_homepage_view() File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 271, in _build_homepage_view self._append_whats_new() File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 450, in _append_whats_new whats_new_cat = self._update_whats_new_content() File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 439, in _update_whats_new_content docs = whats_new_cat.get_documents(self.db) File "/usr/share/software-center/softwarecenter/db/categories.py", line 124, in get_documents nonblocking_load=False) File "/usr/share/software-center/softwarecenter/db/enquire.py", line 317, in set_query self._blocking_perform_search() File "/usr/share/software-center/softwarecenter/db/enquire.py", line 212, in _blocking_perform_search matches = enquire.get_mset(0, self.limit, None, xfilter) File "/usr/share/software-center/softwarecenter/db/appfilter.py", line 89, in __call__ if (not pkgname in self.cache and File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 263, in __contains__ return self._cache.__contains__(k) AttributeError: 'NoneType' object has no attribute '__contains__'

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