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  • Allow users to pull temporary data then delete table data (headers remain)?

    - by JM4
    I don't know the best way to title this question but am trying to accomplish the following goal: When a client logs into their profile, they are presented with a link to download data from an existing database in CSV format. The process works, however, I would like for this data to be 'fresh' each time they click the link so my plan was - once a user has clicked the link and downloaded the CSV file, the database table would 'erase' all of its data and start fresh (be empty) until the next set of data populated it. My EXISTING CSV creation code: <?php $host = 'localhost'; $user = 'username'; $pass = 'password'; $db = 'database'; $table = 'tablename'; $file = 'export'; $link = mysql_connect($host, $user, $pass) or die("Can not connect." . mysql_error()); mysql_select_db($db) or die("Can not connect."); $result = mysql_query("SHOW COLUMNS FROM ".$table.""); $i = 0; if (mysql_num_rows($result) > 0) { while ($row = mysql_fetch_assoc($result)) { $csv_output .= $row['Field'].", "; $i++; } } $csv_output .= "\n"; $values = mysql_query("SELECT * FROM ".$table.""); while ($rowr = mysql_fetch_row($values)) { for ($j=0;$j<$i;$j++) { $csv_output .= '"'.$rowr[$j].'",'; } $csv_output .= "\n"; } $filename = $file."_".date("Y-m-d",time()); header("Content-type: application/vnd.ms-excel"); header("Content-disposition: csv" . date("Y-m-d") . ".csv"); header( "Content-disposition: filename=".$filename.".csv"); print $csv_output; exit; ?> any ideas?

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  • Check mysql_query results if DELETE query worked?

    - by Camran
    I have a DELETE query which deletes a record from a mysql db. is there any way to make sure if the delete was performed or not? I mean, for a query to FIND stuff you do $res=mysql_query($var); $nr=mysql_num_rows($res); and you get nr of rows returned. Is there any similiar method for deletion of records? Thanks

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  • Check value existance while performing a UPDATE query

    - by nimo
    Hi, I need to perform a simple update query where the update should only be done, if there is no value with updating value (item_name). For example, DB table [item_types] item_id(PK) | item_name Assuming there exist item_id with 6, My attempt is UPDATE item_types as k SET k.item_name = 'item_1' WHERE NOT EXISTS (SELECT * FROM item_types as a WHERE a.item_name = 'item_1') AND k.item_id = '6' But this gives me error "You can't specify target table 'k' for update in FROM clause" Could you please explain the error here and how can I achieve this ? Thank you

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  • Find query that caused update

    - by MadMax
    We have been having problems with ghost updates in our DB (SQL Server 2005) fields are changeing and we cannot find the routine that is updating. Is there a way using an update trigger (Or any other way) to tell what caused the update?

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  • Download a file+

    - by Martin
    Hi, First PHP project and I'm stuck! I wish to allow users to click a button or a link and download a file. However, my PHP must first perform some tasks, choose the right file, record the download event in a db etc. This I can do, but how do I then send the file as a response to the user's click? Thanks for any help.

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  • Multiple reference in SQL

    - by AGarofoli
    Hi! I'm working on a db but i'm kinda new to this so i've bumped into a problem today. I've got some tables: OFFICE, ROOM, EMPLOYEE and DOCUMENT. Document must specify the sender, which can be a single employee, an entire room or an entire office so it must have a reference to the primary keys of those tables. Should I do a "parallel" table for handle it (for example i've done one for handle the multiple recipients documents) or there is another way? Thank you

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  • mysql_query() returns returns true, but mysql_num_rows() and mysql_fetch_array() give "not a valid r

    - by zlance4012
    Here is the code in question: -----From index.php----- require_once('includes/DbConnector.php'); // Create an object (instance) of the DbConnector $connector = new DbConnector(); // Execute the query to retrieve articles $query1 = "SELECT id, title FROM articles ORDER BY id DESC LIMIT 0,5"; $result = $connector-query($query1); echo "vardump1:"; var_dump($result); echo "\n"; /(!line 17!)/ echo "Number of rows in the result of the query:".mysql_num_rows($result)."\n"; // Get an array containing the results. // Loop for each item in that array while ($row = $connector-fetchArray($result)){ echo ' '; echo $row['title']; echo ' '; -----end index.php----- -----included DbConnector.php----- $settings = SystemComponent::getSettings(); // Get the main settings from the array we just loaded $host = $settings['dbhost']; $db = $settings['dbname']; $user = $settings['dbusername']; $pass = $settings['dbpassword']; // Connect to the database $this-link = mysql_connect($host, $user, $pass); mysql_select_db($db); register_shutdown_function(array(&$this, 'close')); } //end constructor //* Function: query, Purpose: Execute a database query * function query($query) { echo "Query Statement: ".$query."\n"; $this-theQuery = $query; return mysql_query($query, $this-link) or die(mysql_error()); } //* Function: fetchArray, Purpose: Get array of query results * function fetchArray($result) { echo "<|"; var_dump($result); echo "| \n"; /(!line 50!)/$res= mysql_fetch_array($result) or die(mysql_error()); echo $res['id']."-".$res['title']."-".$res['imagelink']."-".$res['text']; return $res; } -----end DbConnector.php----- -----Output----- Query Statement: SELECT id, title FROM articles ORDER BY id DESC LIMIT 0,5 vardump1:bool(true) PHP Error Message Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resource in /path to/index.php on line 17 Number of rows in the result of the query: <|bool(true) | PHP Error Message Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /path to/DbConnector.php on line 50

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  • Apache-Mina FTPServer Issue — unable to login into apache ftp server while using database user manager

    - by piyush
    I am unable to login into apache ftp server while using database user manager: while entering username and password,I am getting following error in log file: [ INFO] 2013-02-07 20:51:07,779 [] [0:0:0:0:0:0:0:1] RECEIVED: USER piyush [ INFO] 2013-02-07 20:51:07,781 [piyush] [0:0:0:0:0:0:0:1] SENT: 331 User name okay, need password for piyush. [ INFO] 2013-02-07 20:51:07,784 [piyush] [0:0:0:0:0:0:0:1] RECEIVED: PASS ***** [ WARN] 2013-02-07 20:51:07,785 [piyush] [0:0:0:0:0:0:0:1] User failed to log in [ WARN] 2013-02-07 20:51:08,285 [piyush] [0:0:0:0:0:0:0:1] Login failure - piyush [ INFO] 2013-02-07 20:51:08,286 [piyush] [0:0:0:0:0:0:0:1] SENT: 530 Authentication failed. [ INFO] 2013-02-07 20:51:08,286 [piyush] [0:0:0:0:0:0:0:1] RECEIVED: QUIT [ INFO] 2013-02-07 20:51:08,290 [piyush] [0:0:0:0:0:0:0:1] SENT: 221 Goodbye. [ INFO] 2013-02-07 20:51:08,291 [piyush] [0:0:0:0:0:0:0:1] CLOSED here is my xml file ftpd-typical.xml: <?xml version="1.0" encoding="UTF-8"?> <!-- Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. --> <server xmlns="http://mina.apache.org/ftpserver/spring/v1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:beans="http://www.springframework.org/schema/beans" xsi:schemaLocation=" http://mina.apache.org/ftpserver/spring/v1 http://mina.apache.org/ftpserver/ftpserver-1.0.xsd " id="Prometheus"> <listeners> <nio-listener name="default" port="2121" /> </listeners> <db-user-manager encrypt-passwords="salted"> <data-source> <beans:bean class="org.apache.commons.dbcp.BasicDataSource" > <beans:property name="driverClassName" value="com.mysql.jdbc.Driver" /> <beans:property name="url" value="jdbc:mysql://localhost/apache_test" /> <beans:property name="username" value="amy" /> <beans:property name="password" value="piyush" /> </beans:bean> </data-source> <insert-user>INSERT INTO FTP_USER (userid, userpassword, homedirectory, enableflag, writepermission, idletime, uploadrate, downloadrate) VALUES ('{userid}', '{userpassword}', '{homedirectory}', {enableflag}, {writepermission}, {idletime}, {uploadrate}, {downloadrate}) </insert-user> <update-user>UPDATE FTP_USER SET userpassword='{userpassword}',homedirectory='{homedirectory}',enableflag={enableflag},writepermission={writepermission},idletime={idletime},uploadrate={uploadrate},downloadrate={downloadrate} WHERE userid='{userid}' </update-user> <delete-user>DELETE FROM FTP_USER WHERE userid = '{userid}' </delete-user> <select-user>SELECT userid, userpassword, homedirectory, enableflag, writepermission, idletime, uploadrate, downloadrate, maxloginnumber, maxloginperip FROM FTP_USER WHERE userid = '{userid}' </select-user> <select-all-users>SELECT userid FROM FTP_USER ORDER BY userid </select-all-users> <is-admin>SELECT userid FROM FTP_USER WHERE userid='{userid}' AND userid='admin' </is-admin> <authenticate>SELECT userpassword from FTP_USER WHERE userid='{userid}'</authenticate> </db-user-manager> </server>

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  • Broken cups installation on a ubuntu server 64

    - by user67046
    Hi, I am having trouble with an cups installation. It seems to be in a broken state. When i try to reinstall it it stalls, the same if i try to remove it completely. I am running the server version 64 bit of Ubuntu 10.10 with kernel Linux version 2.6.35-22-server. When i try to start the cups daemon with the following command sudo service cups start It just stays there and nothing happens. I have tried to remove it, to be able to reinstall it, with the following command sudo apt-get purge cups It finally stalls with the following message Removing cups ... After that nothing happens. The process tree for the apt-get command looks like this. 1404 1404 1404 ? 00:00:00 sshd 26495 26495 26495 ? 00:00:00 sshd 26581 26495 26495 ? 00:00:00 sshd 26582 26582 26582 pts/4 00:00:00 bash 27158 27158 26582 pts/4 00:00:00 apt-get 27172 27172 27172 pts/2 00:00:00 dpkg 27176 27172 27172 pts/2 00:00:00 cups.prerm 27178 27172 27172 pts/2 00:00:00 stop I have tried to leave the process running for a while to see if i get any error messages but without success. To get out of it I have to kill the processes. sudo dpkg --configure cups dpkg: error processing cups (--configure): package cups is already installed and configured Errors were encountered while processing: cups sudo dpkg --status cups Package: cups Status: purge ok installed Priority: optional Section: net Installed-Size: 8292 Maintainer: Ubuntu Developers <[email protected]> Architecture: amd64 Version: 1.4.4-6ubuntu2.3 Replaces: cupsddk-drivers (<< 1.4.0) Provides: cupsddk-drivers Depends: libavahi-client3 (>= 0.6.16), libavahi-common3 (>= 0.6.16), libc6 (>= 2.7), libcups2 (>= 1.4.4-3~), libcupscgi1 (>= 1.4.2), libcupsdriver1 (>= 1.4.0), libcupsimage2 (>= 1.4.0), libcupsmime1 (>= 1.4.0), libcupsppdc1 (>= 1.4.0), libdbus-1-3 (>= 1.0.2), libgcc1 (>= 1:4.1.1), libgnutls26 (>= 2.7.14-0), libgssapi-krb5-2 (>= 1.8+dfsg), libijs-0.35, libkrb5-3 (>= 1.6.dfsg.2), libldap-2.4-2 (>= 2.4.7), libpam0g (>= 0.99.7.1), libpaper1, libpoppler7, libslp1, libstdc++6 (>= 4.1.1), libusb-0.1-4 (>= 2:0.1.12), zlib1g (>= 1:1.1.4), debconf (>= 1.2.9) | debconf-2.0, upstart-job, poppler-utils (>= 0.12), procps, ghostscript, lsb-base (>= 3), cups-common (>= 1.4.4), cups-client (>= 1.4.4-6ubuntu2.3), ssl-cert (>= 1.0.11), adduser, bc, ttf-freefont, cups-ppdc Recommends: foomatic-filters (>= 4.0), cups-driver-gutenprint, ghostscript-cups Suggests: cups-bsd, foomatic-db-compressed-ppds | foomatic-db, hplip, xpdf-korean | xpdf-japanese | xpdf-chinese-traditional | xpdf-chinese-simplified, cups-pdf, smbclient (>= 3.0.9), udev Breaks: foomatic-filters (<< 4.0) Conflicts: cupsddk-drivers (<< 1.4.0) Conffiles: /etc/fonts/conf.d/99pdftoopvp.conf a5221cfad70a981c80864229ef56586d /etc/logrotate.d/cups 5bb41fa9900f0d1c565954405a2bd7c4 /etc/default/cups 2b436fbb1a32b82b6aba45a76a1d7e40 /etc/pam.d/cups ff2488324854f7b1e892bb0df062d5f0 /etc/init/cups.conf 1a3cd022e8474e3d2b44640f33ce68e3 /etc/ufw/applications.d/cups 29e98a6d850da251e180c3d68dec2bd3 /etc/apparmor.d/usr.sbin.cupsd 60c4b26bfd5c033baa3dd48a3b2e9911 /etc/cups/cupsd.conf e2c7ec15835ea0939e5e86f7c6efcc03 /etc/cups/snmp.conf 2326a8af1e112676d55245bc5eb459ca /etc/cups/cupsd.conf.default a68d54d76021e857dd1d64edf57d36c5 Description: Common UNIX Printing System(tm) - server The Common UNIX Printing System (or CUPS(tm)) is a printing system and general replacement for lpd and the like. It supports the Internet Printing Protocol (IPP), and has its own filtering driver model for handling various document types. . This package provides the CUPS scheduler/daemon and related files. Original-Maintainer: Debian CUPS Maintainers <[email protected]> Would be greatful if someone could provide some help on how to solve this issue.

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  • Can't get network bridging to work

    - by Antonis Christofides
    I'm trying to make network bridging to work on a Debian squeeze (I'm experimenting in order to make a QEMU/KVM virtual machine that will be visible to the outside network as if it were a distinct machine). The problem is that when I type brctl addif br0 eth0 then I lose connectivity to the network until I type brctl delif br0 eth0. More specifically, here's how my machine looks like before I do anything (essentially eth0 is listening on 147.102.160.153): root@laura:/home/anthony# ip addr show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 8c:73:6e:db:1c:1b brd ff:ff:ff:ff:ff:ff inet 147.102.160.153/24 brd 147.102.160.255 scope global eth0 inet6 2001:648:2000:a0:8e73:6eff:fedb:1c1b/64 scope global dynamic valid_lft 2591848sec preferred_lft 604648sec inet6 fe80::8e73:6eff:fedb:1c1b/64 scope link valid_lft forever preferred_lft forever 3: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN qlen 1000 link/ether 4c:ed:de:8e:44:d7 brd ff:ff:ff:ff:ff:ff 4: vboxnet0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000 link/ether 0a:00:27:00:00:00 brd ff:ff:ff:ff:ff:ff 5: pan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether ee:7c:88:59:d0:e8 brd ff:ff:ff:ff:ff:ff Now let me add the bridge: root@laura:/home/anthony# brctl addbr br0 root@laura:/home/anthony# ip tuntap add dev tap0 mode tap root@laura:/home/anthony# ip link set tap0 up root@laura:/home/anthony# brctl addif br0 tap0 Until here everything continues to work normally. Finally, I try to add eth0 to the bridge: root@laura:/home/anthony# brctl addif br0 eth0 At this point, I no longer have a network connection. If I try to ping something, it tells "Destination Host Unreachable". The output of ip addr show seems normal: root@laura:/home/anthony# ip addr show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 8c:73:6e:db:1c:1b brd ff:ff:ff:ff:ff:ff inet 147.102.160.153/24 brd 147.102.160.255 scope global eth0 inet6 2001:648:2000:a0:8e73:6eff:fedb:1c1b/64 scope global dynamic valid_lft 2591908sec preferred_lft 604708sec inet6 fe80::8e73:6eff:fedb:1c1b/64 scope link valid_lft forever preferred_lft forever [snip wlan0, vboxnet0 and pan0, which are down and irrelevant] 8: br0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN link/ether 16:30:f2:67:ab:75 brd ff:ff:ff:ff:ff:ff 9: tap0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 500 link/ether 16:30:f2:67:ab:75 brd ff:ff:ff:ff:ff:ff inet6 fe80::1430:f2ff:fe67:ab75/64 scope link valid_lft forever preferred_lft forever Also: root@laura:/home/anthony# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 147.102.160.0 0.0.0.0 255.255.255.0 U 1 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 1000 0 0 eth0 0.0.0.0 147.102.160.200 0.0.0.0 UG 0 0 0 eth0 I can't understand what I'm doing wrong. I want the machine to continue to listen on 147.102.160.153 on eth0, and in addition to that I want to have a tap0 interface, bridged to eth0, that will be available to the guest machine so that the latter listens on another ip address (say 147.102.160.205). (If there's another way to achieve what I want, I'm also interested.)

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  • Having problems with high CPU usage and apparent memory leak of Exim

    - by Dancrumb
    I'm having problems with my server and am hoping you can help. The culprit appears to be exim. The CPU usage is consistently high and the memory usage trends up and up and up for no apparent reason (this is not a heavily used server). To demonstrate the issue, I ran the following: root@server [/var/log]# service exim restart; for iter in `seq 0 9`; do date; top -n1 | grep exim; sleep 10; done Shutting down exim: [ OK ] Shutting down spamd: [ OK ] Starting exim: [ OK ] Sun Jun 6 18:12:07 CDT 2010 62592 root 25 0 11400 6572 2356 R 51.5 1.3 0:00.92 exim 62587 mailnull 18 0 7548 1212 792 S 0.0 0.2 0:00.00 exim Sun Jun 6 18:12:18 CDT 2010 62592 root 25 0 28768 23m 2356 R 57.4 4.6 0:06.75 exim 62587 mailnull 18 0 7548 1212 792 S 0.0 0.2 0:00.00 exim 62588 root 18 0 7536 2052 1648 S 0.0 0.4 0:00.00 exim Sun Jun 6 18:12:28 CDT 2010 62592 root 25 0 36408 30m 2356 R 55.5 6.0 0:12.59 exim 62587 mailnull 18 0 7548 1212 792 S 0.0 0.2 0:00.00 exim 62588 root 18 0 7536 2052 1648 S 0.0 0.4 0:00.00 exim Sun Jun 6 18:12:39 CDT 2010 62592 root 25 0 41396 35m 2356 R 53.5 7.0 0:18.35 exim 62587 mailnull 18 0 7548 1212 792 S 0.0 0.2 0:00.00 exim 62588 root 18 0 7536 2052 1648 S 0.0 0.4 0:00.00 exim Sun Jun 6 18:12:49 CDT 2010 62592 root 25 0 45868 40m 2356 R 47.5 7.8 0:24.06 exim 62587 mailnull 18 0 7548 1212 792 S 0.0 0.2 0:00.00 exim 62588 root 18 0 7536 2052 1648 S 0.0 0.4 0:00.00 exim Sun Jun 6 18:13:00 CDT 2010 62592 root 25 0 50056 44m 2356 R 55.3 8.6 0:29.84 exim 62587 mailnull 18 0 7548 1212 792 S 0.0 0.2 0:00.00 exim 62588 root 18 0 7536 2052 1648 S 0.0 0.4 0:00.00 exim Sun Jun 6 18:13:10 CDT 2010 62592 root 25 0 53888 47m 2356 R 55.2 9.4 0:35.63 exim 62587 mailnull 18 0 7548 1212 792 S 0.0 0.2 0:00.00 exim 62588 root 18 0 7536 2052 1648 S 0.0 0.4 0:00.00 exim Sun Jun 6 18:13:21 CDT 2010 62592 root 20 0 56920 50m 2356 R 55.3 9.9 0:41.15 exim 62587 mailnull 18 0 7548 1212 792 S 0.0 0.2 0:00.00 exim 62588 root 18 0 7536 2052 1648 S 0.0 0.4 0:00.00 exim Sun Jun 6 18:13:31 CDT 2010 62592 root 25 0 60380 54m 2356 R 53.4 10.6 0:46.98 exim 62587 mailnull 18 0 7548 1212 792 S 0.0 0.2 0:00.00 exim 62588 root 18 0 7536 2052 1648 S 0.0 0.4 0:00.00 exim Sun Jun 6 18:13:42 CDT 2010 62592 root 22 0 63400 57m 2356 R 49.5 11.2 0:52.74 exim 62587 mailnull 18 0 7548 1212 792 S 0.0 0.2 0:00.00 exim 62588 root 18 0 7536 2052 1648 S 0.0 0.4 0:00.00 exim After some time, it gets to a rate of picking up an extra MB every 10s. I've checked the exim logs and there are no messages coming in there. exim -bV shows: Exim version 4.69 #1 built 16-Mar-2009 14:44:43 Copyright (c) University of Cambridge 2006 Berkeley DB: Sleepycat Software: Berkeley DB 4.2.52: (February 22, 2005) Support for: crypteq iconv() IPv6 PAM Perl OpenSSL Content_Scanning Old_Demime Experimental_SPF Experimental_SRS Experimental_DomainKeys Lookups: lsearch wildlsearch nwildlsearch iplsearch dbm dbmnz passwd Authenticators: cram_md5 dovecot plaintext spa Routers: accept dnslookup ipliteral manualroute queryprogram redirect Transports: appendfile/maildir autoreply pipe smtp Size of off_t: 8 Configuration file is /etc/exim.conf I'm at something of a loss as to how to proceed. Any recommendations would be well received!

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  • Is the Cloud ready for an Enterprise Java web application? Seeking a JEE hosting advice.

    - by Jakub Holý
    Greetings to all the smart people around here! I'd like to ask whether it is feasible or a good idea at all to deploy a Java enterprise web application to a Cloud such as Amazon EC2. More exactly, I'm looking for infrastructure options for an application that shall handle few hundred users with long but neither CPU nor memory intensive sessions. I'm considering dedicated servers, virtual private servers (VPSs) and EC2. I've noticed that there is a project called JBoss Cloud so people are working on enabling such a deployment, on the other hand it doesn't seem to be mature yet and I'm not sure that the cloud is ready for this kind of applications, which differs from the typical cloud-based applications like Twitter. Would you recommend to deploy it to the cloud? What are the pros and cons? The application is a Java EE 5 web application whose main function is to enable users to compose their own customized Product by combining the available Parts. It uses stateless and stateful session beans and JPA for persistence of entities to a RDBMS and fetches information about Parts from the company's inventory system via a web service. Aside of external users it's used also by few internal ones, who are authenticated against the company's LDAP. The application should handle around 300-400 concurrent users building their product and should be reasonably scalable and available though these qualities are only of a medium importance at this stage. I've proposed an architecture consisting of a firewall (FW) and load balancer supporting sticky sessions and https (in the Cloud this would be replaced with EC2's Elastic Load Balancing service and FW on the app. servers, in a physical architecture the load-balancer would be a HW), then two physical clustered application servers combined with web servers (so that if one fails, a user doesn't loose his/her long built product) and finally a database server. The DB server would need a slave backup instance that can replace the master instance if it fails. This should provide reasonable availability and fault tolerance and provide good scalability as long as a single RDBMS can keep with the load, which should be OK for quite a while because most of the operations are done in the memory using a stateful bean and only occasionally stored or retrieved from the DB and the amount of data is low too. A problematic part could be the dependency on the remote inventory system webservice but with good caching of its outputs in the application it should be OK too. Unfortunately I've only vague idea of the system resources (memory size, number and speed of CPUs/cores) that such an "average Java EE application" for few hundred users needs. My rough and mostly unfounded estimate based on actual Amazon offerings is that 1.7GB and a single, 2-core "modern CPU" with speed around 2.5GHz (the High-CPU Medium Instance) should be sufficient for any of the two application servers (since we can handle higher load by provisioning more of them). Alternatively I would consider using the Large instance (64b, 7.5GB RAM, 2 cores at 1GHz) So my question is whether such a deployment to the cloud is technically and financially feasible or whether dedicated/VPS servers would be a better option and whether there are some real-world experiences with something similar. Thank you very much! /Jakub Holy PS: I've found the JBoss EAP in a Cloud Case Study that shows that it is possible to deploy a real-world Java EE application to the EC2 cloud but unfortunately there're no details regarding topology, instance types, or anything :-(

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