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  • Apache with mod_php high memory utilization

    - by Raj
    We have Magento application deployed on Apache with mod_php and mysql. I have observed that sometime apache server starts consuming high memory which causes memory swapping and results in high load on servers. whenever there is high load on apache server, the apache processes which are causing the high load were in sleep mode at mysql end and CLOSE_WAIT state at client side. Any help is appreciated to resolve this issue.

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  • Biztalk - how do I set up MSMQ load balancing and high availability ?

    - by FullOfQuestions
    Hi, From what I understand, in order to achieve MSMQ load-balancing, one must use a technology such as NLB. And in order to achieve MSMQ high-availability, one must cluster the related Biztalk Host (and hence the underlying servers have to be in a cluster themselves). Yet, according to Microsoft Documentation, NLB and FailOver Clustering technologies are not compatible. See this link for reference: http://support.microsoft.com/kb/235305 Can anyone PLEASE explain to me how MSMQ load-balancing and high-availability can be achieved? thank you in advance, M

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  • virtual serial port on Arch linux

    - by Milan
    Hello, I am using Arch linux and I need to create virtual serial port on it. I tried everything but it seems doesnt work. All I want is to connect that virtual port to another virtual port over TCP and after that to use it in my python application to communicate with python application to other side. Is that posible? Please help me. Thanx

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  • Microsoft SQL Server 2008 R2 Administration Cookbook - Book and eBook expected June 2011. Pre-order now!

    - by ssqa.net
    Over 85 practical recipes for administering a high-performance SQL Server 2008 R2 system. Book and eBook expected June 2011 . Pre-order now! Multi-format orders get free access on PacktLib , This practical cookbook will show you the advanced administration techniques for managing and administering a scalable and high-performance SQL Server 2008 R2 system. It contains over 85 practical, task-based, and immediately useable recipes covering a wide range of advanced administration techniques for administering...(read more)

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  • High Load mysql on Debian server stops every day. Why?

    - by Oleg Abrazhaev
    I have Debian server with 32 gb memory. And there is apache2, memcached and nginx on this server. Memory load always on maximum. Only 500m free. Most memory leak do MySql. Apache only 70 clients configured, other services small memory usage. When mysql use all memory it stops. And nothing works, need mysql reboot. Mysql configured use maximum 24 gb memory. I have hight weight InnoDB bases. (400000 rows, 30 gb). And on server multithread daemon, that makes many inserts in this tables, thats why InnoDB. There is my mysql config. [mysqld] # # * Basic Settings # default-time-zone = "+04:00" user = mysql pid-file = /var/run/mysqld/mysqld.pid socket = /var/run/mysqld/mysqld.sock port = 3306 basedir = /usr datadir = /var/lib/mysql tmpdir = /tmp language = /usr/share/mysql/english skip-external-locking default-time-zone='Europe/Moscow' # # Instead of skip-networking the default is now to listen only on # localhost which is more compatible and is not less secure. # # * Fine Tuning # #low_priority_updates = 1 concurrent_insert = ALWAYS wait_timeout = 600 interactive_timeout = 600 #normal key_buffer_size = 2024M #key_buffer_size = 1512M #70% hot cache key_cache_division_limit= 70 #16-32 max_allowed_packet = 32M #1-16M thread_stack = 8M #40-50 thread_cache_size = 50 #orderby groupby sort sort_buffer_size = 64M #same myisam_sort_buffer_size = 400M #temp table creates when group_by tmp_table_size = 3000M #tables in memory max_heap_table_size = 3000M #on disk open_files_limit = 10000 table_cache = 10000 join_buffer_size = 5M # This replaces the startup script and checks MyISAM tables if needed # the first time they are touched myisam-recover = BACKUP #myisam_use_mmap = 1 max_connections = 200 thread_concurrency = 8 # # * Query Cache Configuration # #more ignored query_cache_limit = 50M query_cache_size = 210M #on query cache query_cache_type = 1 # # * Logging and Replication # # Both location gets rotated by the cronjob. # Be aware that this log type is a performance killer. #log = /var/log/mysql/mysql.log # # Error logging goes to syslog. This is a Debian improvement :) # # Here you can see queries with especially long duration log_slow_queries = /var/log/mysql/mysql-slow.log long_query_time = 1 log-queries-not-using-indexes # # The following can be used as easy to replay backup logs or for replication. # note: if you are setting up a replication slave, see README.Debian about # other settings you may need to change. #server-id = 1 #log_bin = /var/log/mysql/mysql-bin.log server-id = 1 log-bin = /var/lib/mysql/mysql-bin #replicate-do-db = gate log-bin-index = /var/lib/mysql/mysql-bin.index log-error = /var/lib/mysql/mysql-bin.err relay-log = /var/lib/mysql/relay-bin relay-log-info-file = /var/lib/mysql/relay-bin.info relay-log-index = /var/lib/mysql/relay-bin.index binlog_do_db = 24avia expire_logs_days = 10 max_binlog_size = 100M read_buffer_size = 4024288 innodb_buffer_pool_size = 5000M innodb_flush_log_at_trx_commit = 2 innodb_thread_concurrency = 8 table_definition_cache = 2000 group_concat_max_len = 16M #binlog_do_db = gate #binlog_ignore_db = include_database_name # # * BerkeleyDB # # Using BerkeleyDB is now discouraged as its support will cease in 5.1.12. #skip-bdb # # * InnoDB # # InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/. # Read the manual for more InnoDB related options. There are many! # You might want to disable InnoDB to shrink the mysqld process by circa 100MB. #skip-innodb # # * Security Features # # Read the manual, too, if you want chroot! # chroot = /var/lib/mysql/ # # For generating SSL certificates I recommend the OpenSSL GUI "tinyca". # # ssl-ca=/etc/mysql/cacert.pem # ssl-cert=/etc/mysql/server-cert.pem # ssl-key=/etc/mysql/server-key.pem [mysqldump] quick quote-names max_allowed_packet = 500M [mysql] #no-auto-rehash # faster start of mysql but no tab completition [isamchk] key_buffer = 32M key_buffer_size = 512M # # * NDB Cluster # # See /usr/share/doc/mysql-server-*/README.Debian for more information. # # The following configuration is read by the NDB Data Nodes (ndbd processes) # not from the NDB Management Nodes (ndb_mgmd processes). # # [MYSQL_CLUSTER] # ndb-connectstring=127.0.0.1 # # * IMPORTANT: Additional settings that can override those from this file! # The files must end with '.cnf', otherwise they'll be ignored. # !includedir /etc/mysql/conf.d/ Please, help me make it stable. Memory used /etc/mysql # free total used free shared buffers cached Mem: 32930800 32766424 164376 0 139208 23829196 -/+ buffers/cache: 8798020 24132780 Swap: 33553328 44660 33508668 Maybe my problem not in memory, but MySQL stops every day. As you can see, cache memory free 24 gb. Thank to Michael Hampton? for correction. Load overage on server 3.5. Maybe hdd or another problem? Maybe my config not optimal for 30gb InnoDB ? I'm already try mysqltuner and tunung-primer.sh , but they marked all green. Mysqltuner output mysqltuner >> MySQLTuner 1.0.1 - Major Hayden <[email protected]> >> Bug reports, feature requests, and downloads at http://mysqltuner.com/ >> Run with '--help' for additional options and output filtering -------- General Statistics -------------------------------------------------- [--] Skipped version check for MySQLTuner script [OK] Currently running supported MySQL version 5.5.24-9-log [OK] Operating on 64-bit architecture -------- Storage Engine Statistics ------------------------------------------- [--] Status: -Archive -BDB -Federated +InnoDB -ISAM -NDBCluster [--] Data in MyISAM tables: 112G (Tables: 1528) [--] Data in InnoDB tables: 39G (Tables: 340) [--] Data in PERFORMANCE_SCHEMA tables: 0B (Tables: 17) [!!] Total fragmented tables: 344 -------- Performance Metrics ------------------------------------------------- [--] Up for: 8h 18m 33s (14M q [478.333 qps], 259K conn, TX: 9B, RX: 5B) [--] Reads / Writes: 84% / 16% [--] Total buffers: 10.5G global + 81.1M per thread (200 max threads) [OK] Maximum possible memory usage: 26.3G (83% of installed RAM) [OK] Slow queries: 1% (259K/14M) [!!] Highest connection usage: 100% (201/200) [OK] Key buffer size / total MyISAM indexes: 1.5G/5.6G [OK] Key buffer hit rate: 100.0% (6B cached / 1M reads) [OK] Query cache efficiency: 74.3% (8M cached / 11M selects) [OK] Query cache prunes per day: 0 [OK] Sorts requiring temporary tables: 0% (0 temp sorts / 247K sorts) [!!] Joins performed without indexes: 106025 [!!] Temporary tables created on disk: 49% (351K on disk / 715K total) [OK] Thread cache hit rate: 99% (249 created / 259K connections) [!!] Table cache hit rate: 15% (2K open / 13K opened) [OK] Open file limit used: 15% (3K/20K) [OK] Table locks acquired immediately: 99% (4M immediate / 4M locks) [!!] InnoDB data size / buffer pool: 39.4G/5.9G -------- Recommendations ----------------------------------------------------- General recommendations: Run OPTIMIZE TABLE to defragment tables for better performance MySQL started within last 24 hours - recommendations may be inaccurate Reduce or eliminate persistent connections to reduce connection usage Adjust your join queries to always utilize indexes Temporary table size is already large - reduce result set size Reduce your SELECT DISTINCT queries without LIMIT clauses Increase table_cache gradually to avoid file descriptor limits Variables to adjust: max_connections (> 200) wait_timeout (< 600) interactive_timeout (< 600) join_buffer_size (> 5.0M, or always use indexes with joins) table_cache (> 10000) innodb_buffer_pool_size (>= 39G) Mysql primer output -- MYSQL PERFORMANCE TUNING PRIMER -- - By: Matthew Montgomery - MySQL Version 5.5.24-9-log x86_64 Uptime = 0 days 8 hrs 20 min 50 sec Avg. qps = 478 Total Questions = 14369568 Threads Connected = 16 Warning: Server has not been running for at least 48hrs. It may not be safe to use these recommendations To find out more information on how each of these runtime variables effects performance visit: http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html Visit http://www.mysql.com/products/enterprise/advisors.html for info about MySQL's Enterprise Monitoring and Advisory Service SLOW QUERIES The slow query log is enabled. Current long_query_time = 1.000000 sec. You have 260626 out of 14369701 that take longer than 1.000000 sec. to complete Your long_query_time seems to be fine BINARY UPDATE LOG The binary update log is enabled Binlog sync is not enabled, you could loose binlog records during a server crash WORKER THREADS Current thread_cache_size = 50 Current threads_cached = 45 Current threads_per_sec = 0 Historic threads_per_sec = 0 Your thread_cache_size is fine MAX CONNECTIONS Current max_connections = 200 Current threads_connected = 11 Historic max_used_connections = 201 The number of used connections is 100% of the configured maximum. You should raise max_connections INNODB STATUS Current InnoDB index space = 214 M Current InnoDB data space = 39.40 G Current InnoDB buffer pool free = 0 % Current innodb_buffer_pool_size = 5.85 G Depending on how much space your innodb indexes take up it may be safe to increase this value to up to 2 / 3 of total system memory MEMORY USAGE Max Memory Ever Allocated : 23.46 G Configured Max Per-thread Buffers : 15.84 G Configured Max Global Buffers : 7.54 G Configured Max Memory Limit : 23.39 G Physical Memory : 31.40 G Max memory limit seem to be within acceptable norms KEY BUFFER Current MyISAM index space = 5.61 G Current key_buffer_size = 1.47 G Key cache miss rate is 1 : 5578 Key buffer free ratio = 77 % Your key_buffer_size seems to be fine QUERY CACHE Query cache is enabled Current query_cache_size = 200 M Current query_cache_used = 101 M Current query_cache_limit = 50 M Current Query cache Memory fill ratio = 50.59 % Current query_cache_min_res_unit = 4 K MySQL won't cache query results that are larger than query_cache_limit in size SORT OPERATIONS Current sort_buffer_size = 64 M Current read_rnd_buffer_size = 256 K Sort buffer seems to be fine JOINS Current join_buffer_size = 5.00 M You have had 106606 queries where a join could not use an index properly You have had 8 joins without keys that check for key usage after each row join_buffer_size >= 4 M This is not advised You should enable "log-queries-not-using-indexes" Then look for non indexed joins in the slow query log. OPEN FILES LIMIT Current open_files_limit = 20210 files The open_files_limit should typically be set to at least 2x-3x that of table_cache if you have heavy MyISAM usage. Your open_files_limit value seems to be fine TABLE CACHE Current table_open_cache = 10000 tables Current table_definition_cache = 2000 tables You have a total of 1910 tables You have 2151 open tables. The table_cache value seems to be fine TEMP TABLES Current max_heap_table_size = 2.92 G Current tmp_table_size = 2.92 G Of 366426 temp tables, 49% were created on disk Perhaps you should increase your tmp_table_size and/or max_heap_table_size to reduce the number of disk-based temporary tables Note! BLOB and TEXT columns are not allow in memory tables. If you are using these columns raising these values might not impact your ratio of on disk temp tables. TABLE SCANS Current read_buffer_size = 3 M Current table scan ratio = 2846 : 1 read_buffer_size seems to be fine TABLE LOCKING Current Lock Wait ratio = 1 : 185 You may benefit from selective use of InnoDB. If you have long running SELECT's against MyISAM tables and perform frequent updates consider setting 'low_priority_updates=1'

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  • Apache: set aside specific number of servers for a single "high priority" script

    - by Disco
    I have a bunch of scripts, but some of them are higher priority than others: /var/www/normal-priority/script1.pl /var/www/normal-priority/script2.pl /var/www/normal-priority/script3.pl and /var/www/high-priority/script1.pl /var/www/high-priority/script2.pl /var/www/high-priority/script3.pl All running under mod-perl. They reside in separate directories. From time to time, the normal-priority scripts get very busy, and the httpd servers "swamp out" the less frequently called high priority ones. Is it possible to set aside n httpd servers so that they only listen for the "high priority" scripts?

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  • How do I optimize a high traffic Wordpress website?

    - by mha
    Hello, I am running a wordpress based site which is now hosted on (mt) under DV-Extreme package 2GB+256MB addon RAM. It a muti author site where people are engaged in writing posts, comments, updating status etc. According to Google Analytics this month traffic Visitor = 45,764 Pageview = 1,051,186 Visit = 141,447 I have cdn my site, compress the css, used w3 Total cache plugin to optimize my site. Since last month I am getting several down notice from Pingdom. Right now I am facing more down alert than before. And have to restart my site several time to up again. Is my hosting resource is not enough? Do I need more resource? or what could be the solution? Helpful suggestion will be appreciated. Thanks.

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  • is it possible to synchronize the states of TCP proxies in real time (for real-high-availability of SLB)?

    - by Song
    Consider that there are two server load balancers working in the tcp proxy mode (e.g., for L7 load balancing). Is it possible to synchronize their states in real time so that they can be a backup for each other? in case that one is down, the other still has all necessary states to uninterruptedly support all existing TCP connections. I understand that this is hard, but I am wondering whether any free/commercial LB already supports this feature. Thank you!

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  • Software for "High-level" source code (C++) Management

    - by Korchkidu
    after a lot of small-medium projects, I have a lot of libraries and test programs here and there. Also, I must admit that some of the "best practices" I learnt are not that "good" IMHO. In particular, documenting your code and making a "high-level" documentation is not useful in practice: High-level documentation are not maintain up to date = I prefer to read the source code directly; Browsing generated developer documentation is a pain (IMHO) = I prefer to read the source code directly. For that reason, I am looking for a tool who could help me organize all my source code directories in a more "readable manner". What I need is a tool which: Maintains an UML diagram from C++ source code. I don't need source code generation from UML; USE CASE: I am in this super-tool, I notice a design issue, I change the source code, when I get back, the UML diagram is updated; Maintains easily browsable call graphs; Lists references to methods, variables, etc. For example, when I want to see where/when a method is called; Helps writing pseudo-code from C++; Embeds a nice C++ source code browser; Is Open Source would be great; Works at least on Win7. The focus of this tool should be to browse source code to understand what's going on. For example, when you have a newcomer and you need him to go through source code. Do you know any great tool? Thanks in advance. PS: please do not answer doxygen (great tool however).

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  • Apache VERY high page load time

    - by Aaron Waller
    My Drupal 6 site has been running smoothly for years but recently has experienced intermittent periods of extreme slowness (10-60 sec page loads). Several hours of slowness followed by hours of normal (4-6 sec) page loads. The page always loads with no error, just sometimes takes forever. My setup: Windows Server 2003 Apache/2.2.15 (Win32) Jrun/4.0 PHP 5 MySql 5.1 Drupal 6 Cold fusion 9 Vmware virtual environment DMZ behind a corporate firewall Traffic: 1-3 hits/sec avg Troubleshooting No applicable errors in apache error log No errors in drupal event log Drupal devel module shows 242 queries in 366.23 milliseconds,page execution time 2069.62 ms. (So it looks like queries and php scripts are not the problem) NO unusually high CPU, memory, or disk IO Cold fusion apps, and other static pages outside of drupal also load slow webpagetest.org test shows very high time-to-first-byte The problem seems to be with Apache responding to requests, but previously I've only seen this behavior under 100% cpu load. Judging solely by resource monitoring, it looks as though very little is going on. Here is the kicker - roughly half of the site's access comes from our LAN, but if I disable the firewall rule and block access from outside of our network, internal (LAN) access (1000+ devices) is speedy. But as soon as outside access is restored the site is crippled. Apache config? Crawlers/bots? Attackers? I'm at the end of my rope, where should I be looking to determine where the problem lies?

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  • SQL – Crossword Puzzle Based on Course Building Successful High Traffic Profitable Blog

    - by Pinal Dave
    Do you like Crossword Puzzles? I personally love it. Everytime I open the newspaper, I try to resolve at least one crossword or sudoku. It is just fun to tease a brain little and stretch its limits. Regular readers of the blogs are aware that I have recently published two courses on how to build successful high traffic profitable blog. Here are the links to watch both the courses: Course 1, Course 2. Do watch them in order as both the courses have unique content, which can help you build a better blog. On my birthday July 30th, there was an interesting blog post posted on Pluralsight blog. It was a crossword build from my two courses. I encourage you try to solve the crossword which I have built. Giveaway: There is a cool gift for the winner – it is melting clock. Do not confuse this as a dummy or not working clock. This looks like melting but it always shows accurate time and it is perfectly balanced to hang off of any flat surface. How to Participate: Well, it is very simple, you just have to complete the crossword and send it to me at pinal at sqlauthority.com with all valid answers. The deadline is that you must send it before Monday August 5, 2013 or before the valid answer keys are posted on Pluralsight blog. Hints: Though the crossword is very easy and intuitive, if you ever get stuck anywhere here are two hints: Hint 1, Hint 2. Login to Pluralsight courses and watch both the courses. Watching the course will not only help you to easily complete crossword but there are hidden gems and secrets to build a high traffic profitable blog. Here is the link to download the crossword: Download Crossword. Alternatively you can download the image displayed below and print it as well.   Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: About Me, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology Tagged: Blogging

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  • Is this high coupling?

    - by Bono
    Question I'm currently working a on an assignment for school. The assignment is to create a puzzle/calculator program in which you learn how to work with different datastructures (such as Stacks). We have generate infix math strings suchs as "1 + 2 * 3 - 4" and then turn them in to postfix math strings such as "1 2 + 3 * 4 -". In my book the author creates a special class for converting the infix notation to postfix. I was planning on using this but whilst I was about to implement it I was wondering if the following is what you would call "high coupling". I have read something about this (nothing that is taught in the book or anything) and was wondering about the aspect (since I still have to grasp it). Problem I have created a PuzzleGenerator class which generates the infix notation of the puzzle (or math string, whatever you want to call it) when it's instantiated. I was going to make a method getAnswer() in which I would instantiate the InToPost class (the class from the book) to convert the infix to postfox notation and then calculate the answer. But whilst doing this I thought: "Is using the InToPost class inside this method a form a high coupling, and would it be better to place this in a different method?" (such as a "convertPostfixToInfix" method, inside the PuzzleGenerator class) Thanks in advance.

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  • Store scores for players and produce a high score list

    - by zrvan
    This question is derived from an interview question that I got for a job I was declined. I have asked for code review for my solution at the dedicated Stack Exchange site. But I hope this question is sufficiently rephrased and asked with a different motivation not to be a duplicate of the other question. Consider the following scenario: You should store player scores in the server back end of a game. The server is written in Java. Every score should be registered, that is, one player may have any number of scores for any number of levels. A high score list should be produced with the fifteen top scores for a given level, but only one score per user (to the effect that even if player X has the two highest scores for level Y, only the first position is counted and player Z has the second place). No information should be persisted and only Java 1.7+ standard libraries should be used. No third party libraries or frameworks are acceptable. With the number of players as the primary factor, what would be the best data structure in terms of scalability and concurrency? How would you access the structure to register a single score given a level and a player id? How would you access the structure to compile the high score list?

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  • Evolution Of High Definition TV Viewing

    - by Gopinath
    The following guest post is written by Rob, who is also blogging on entertainment technology topics on iwantsky.com Gone are the days when you need to squint to be able to see the emotions on the faces of Humphrey Bogart and Ingrid Bergman as the lovers bid each other adieu in the classic film Casablanca. These days, watching an ordinary ant painstakingly carry a leaf in Animal Planet can be an exhilarating experience as you get to see not only the slightest movement but also the demarcation line between the insect’s head, thorax and abdomen. The crystal clear imagery was made possible by the sharp minds and the tinkering hands of the scientists that have designed the modern world’s HDTV. What is HDTV and what makes people so agog to have this new innovation in TV watching? HDTV stands for High Definition TV. Television viewing has indeed made a big leap. From the grainy black and whites, TV viewing had moved to colored TVs, progressed to SD TVs and now to HDTV. HDTV is the emerging trend in TV viewing as it delivers bigger and clearer pictures and better audio. Viewers can have a cinema-like TV viewing experience right in the comforts of their own home. With HDTV the viewer is allowed to have a better viewing range. With Standard (SD) TV, the viewer has to be at a distance that is from 3 to 6 times the size of the screen. HDTV allows the viewer to enjoy sharper and clearer images as it is possible to sit at a distance that is 1.5 or 3 times the size of the screen without noticing any image pixilation. Although HDTV appears to be a fairly new innovation, this system has actually existed in various forms years ago. Development of the HDTV was started in Europe as early as 1940s. However, the NTSC and the PAL/SECAM, the two analog TV standards became dominant and became popular worldwide. The analog TV was replaced by the digital TV platform in the 1990s. Even during the analog era, attempts have been made to develop HDTV. Japan has come out with MUSE system. However, due to channel bandwidth requirement concerns, the program was shelved. The entry of four organizations into the HDTV market spurred the development of a beneficial coalition. The AT&T, ATRC, MIT and Zenith HDTV combined forces. In 1993, a Grand Alliance was formed. This group is composed of researchers and HDTV manufacturers. A common standard for the broadcast system of HDTV was developed. In 1995, the system was tested and found successful. With the higher screen resolution of HDTV, viewing has never been more enjoyable. [Image courtesy: samsung] This article titled,Evolution Of High Definition TV Viewing, was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

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  • Edinburgh this Thurs (25th) - Rob Carrol talks about how to build a high performance, scalable repor

    - by tonyrogerson
    Scottish Area SQL Server User Group Meeting, Edinburgh - Thursday 25th March An evening of SQL Server 2008 Reporting Services Scalability and Performance with Rob Carrol, see how to build a high performance, scalable reporting platform and the tuning techniques required to ensure that report performance remains optimal as your platform grows. Pizza and drinks will be provided! Register at http://www.sqlserverfaq.com/events/221/SQL-Server-2008-Reporting-Services-Scalability-and-Performance.aspx...(read more)

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  • Oracle Coherence 3.5 : Create Internet-scale applications using Oracle's high-performance data grid

    - by frederic.michiara
    Oracle Coherence Coherence provides replicated and distributed (partitioned) data management and caching services on top of a reliable, highly scalable peer-to-peer clustering protocol. Coherence has no single points of failure; it automatically and transparently fails over and redistributes its clustered data management services when a server becomes inoperative or is disconnected from the network. When a new server is added, or when a failed server is restarted, it automatically joins the cluster and Coherence fails back services to it, transparently redistributing the cluster load. Coherence includes network-level fault tolerance features and transparent soft re-start capability to enable servers to self-heal. For the ones looking at an easy reading and first good approach to Oracle Coherence, I would recommend reading the following book : Overview of Oracle Coherence 3.5 Build scalable web sites and Enterprise applications using a market-leading data grid product Design and implement your domain objects to work most effectively with Coherence and apply Domain Driven Designs (DDD) to Coherence applications Leverage Coherence events and continuous queries to provide real-time updates to client applications Successfully integrate various persistence technologies, such as JDBC, Hibernate, or TopLink, with Coherence Filled with numerous examples that provide best practice guidance, and a number of classes you can readily reuse within your own applications This book is targeted to Architects and developers, and as in our team we're more about Solutions Architects than developers I found interest in this book as it help to understand better Oracle Coherence and its value. The only point I may not agree with the authors is that Oracle Coherence is not an alternative to Oracle RAC in providing High Availability, but combining both Oracle RAC and Oracle Coherence will help Architects and Customers to reach higher level of service and high-availability. This book is available on https://www.packtpub.com/oracle-coherence-3-5/book Need to find out about Table of contents : https://www.packtpub.com/toc/oracle-coherence-35-table-contents Discover a sample chapter : https://www.packtpub.com/sites/default/files/6125_Oracle%20Coherence_SampleChapter.pdf Read also articles from the Authors on http://www.packtpub.com/ : Working with Aggregators in Oracle Coherence 3.5 Working with Value Extractors and Simplifying Queries in Oracle Coherence 3.5 Querying the Data Grid in Coherence 3.5: Obtaining Query Results and Using Indexes Installing Coherence 3.5 and Accessing the Data Grid: Part 1 Installing Coherence 3.5 and Accessing the Data Grid: Part 2 For more information on Oracle Coherence : What Oracle Coherence Can Do for You... : http://www.oracle.com/technology/products/coherence/coherencedatagrid/coherence_solutions.html Oracle Coherence on OTN : http://www.oracle.com/technology/products/coherence/index.html Oracle Coherence Knowledge Base : http://coherence.oracle.com/display/COH/Oracle+Coherence+Knowledge+Base+Home

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  • Linux can't find file that exists

    - by Joe
    I'm trying to get Google's Dart language up and running, but it errors when running dart2js. I'm running Arch linux and I installed dart-sdk from AUR. Some relevant terminal output lies below. % dart2js main.dart /usr/local/bin/dart2js: line 7: /usr/local/bin/dart: No such file or directory % cat /usr/local/bin/dart2js #!/bin/sh # Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file # for details. All rights reserved. Use of this source code is governed by a # BSD-style license that can be found in the LICENSE file. BIN_DIR=`dirname $0` exec $BIN_DIR/dart --allow_string_plus=false $BIN_DIR/../lib/dart2js/lib/compiler/implementation/dart2js.dart "$@" % file /usr/local/bin/dart /usr/local/bin/dart: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.15, BuildID[sha1]=0x27fe166ca015c1adfeaf3a6f9c018e7d7af46d9f, stripped % ls -alh /usr/local/bin total 4.9M drwxr-xr-x 2 root root 4.0K Jun 10 22:51 . drwxr-xr-x 12 root root 4.0K Jun 10 22:51 .. -rwxr-xr-x 1 root root 422K May 10 22:41 cargo -rwxr-xr-x 1 root root 2.7M Jun 10 22:50 dart -rwxr-xr-x 1 root root 360 Jun 6 16:20 dart2js -rwxr-xr-x 1 root root 176 Jun 6 16:20 pub -rwxr-xr-x 1 root root 166K May 10 22:41 rustc -rwxr-xr-x 1 root root 1.6M May 10 22:41 rustdoc % uname -rm 3.3.7-1-ARCH x86_64 Could it be because I'm running a 64bit OS and the dart binary is 32bit?

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  • Evolution Of High Definition TV Viewing

    - by Gopinath
    The following guest post is written by Rob, who is also blogging on entertainment technology topics on iwantsky.com Gone are the days when you need to squint to be able to see the emotions on the faces of Humphrey Bogart and Ingrid Bergman as the lovers bid each other adieu in the classic film Casablanca. These days, watching an ordinary ant painstakingly carry a leaf in Animal Planet can be an exhilarating experience as you get to see not only the slightest movement but also the demarcation line between the insect’s head, thorax and abdomen. The crystal clear imagery was made possible by the sharp minds and the tinkering hands of the scientists that have designed the modern world’s HDTV. What is HDTV and what makes people so agog to have this new innovation in TV watching? HDTV stands for High Definition TV. Television viewing has indeed made a big leap. From the grainy black and whites, TV viewing had moved to colored TVs, progressed to SD TVs and now to HDTV. HDTV is the emerging trend in TV viewing as it delivers bigger and clearer pictures and better audio. Viewers can have a cinema-like TV viewing experience right in the comforts of their own home. With HDTV the viewer is allowed to have a better viewing range. With Standard (SD) TV, the viewer has to be at a distance that is from 3 to 6 times the size of the screen. HDTV allows the viewer to enjoy sharper and clearer images as it is possible to sit at a distance that is 1.5 or 3 times the size of the screen without noticing any image pixilation. Although HDTV appears to be a fairly new innovation, this system has actually existed in various forms years ago. Development of the HDTV was started in Europe as early as 1940s. However, the NTSC and the PAL/SECAM, the two analog TV standards became dominant and became popular worldwide. The analog TV was replaced by the digital TV platform in the 1990s. Even during the analog era, attempts have been made to develop HDTV. Japan has come out with MUSE system. However, due to channel bandwidth requirement concerns, the program was shelved. The entry of four organizations into the HDTV market spurred the development of a beneficial coalition. The AT&T, ATRC, MIT and Zenith HDTV combined forces. In 1993, a Grand Alliance was formed. This group is composed of researchers and HDTV manufacturers. A common standard for the broadcast system of HDTV was developed. In 1995, the system was tested and found successful. With the higher screen resolution of HDTV, viewing has never been more enjoyable. [Image courtesy: samsung] This article titled,Evolution Of High Definition TV Viewing, was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

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  • Windows Azure Use Case: High-Performance Computing (HPC)

    - by BuckWoody
    This is one in a series of posts on when and where to use a distributed architecture design in your organization's computing needs. You can find the main post here: http://blogs.msdn.com/b/buckwoody/archive/2011/01/18/windows-azure-and-sql-azure-use-cases.aspx  Description: High-Performance Computing (also called Technical Computing) at its most simplistic is a layout of computer workloads where a “head node” accepts work requests, and parses them out to “worker nodes'”. This is useful in cases such as scientific simulations, drug research, MatLab work and where other large compute loads are required. It’s not the immediate-result type computing many are used to; instead, a “job” or group of work requests is sent to a cluster of computers and the worker nodes work on individual parts of the calculations and return the work to the scheduler or head node for the requestor in a batch-request fashion. This is typical to the way that many mainframe computing use-cases work. You can use commodity-based computers to create an HPC Cluster, such as the Linux application called Beowulf, and Microsoft has a server product for HPC using standard computers, called the Windows Compute Cluster that you can read more about here. The issue with HPC (from any vendor) that some organization have is the amount of compute nodes they need. Having too many results in excess infrastructure, including computers, buildings, storage, heat and so on. Having too few means that the work is slower, and takes longer to return a result to the calling application. Unless there is a consistent level of work requested, predicting the number of nodes is problematic. Implementation: Recently, Microsoft announced an internal partnership between the HPC group (Now called the Technical Computing Group) and Windows Azure. You now have two options for implementing an HPC environment using Windows. You can extend the current infrastructure you have for HPC by adding in Compute Nodes in Windows Azure, using a “Broker Node”.  You can then purchase time for adding machines, and then stop paying for them when the work is completed. This is a common pattern in groups that have a constant need for HPC, but need to “burst” that load count under certain conditions. The second option is to install only a Head Node and a Broker Node onsite, and host all Compute Nodes in Windows Azure. This is often the pattern for organizations that need HPC on a scheduled and periodic basis, such as financial analysis or actuarial table calculations. References: Blog entry on Hybrid HPC with Windows Azure: http://blogs.msdn.com/b/ignitionshowcase/archive/2010/12/13/high-performance-computing-on-premise-and-in-the-windows-azure-cloud.aspx  Links for further research on HPC, includes Windows Azure information: http://blogs.msdn.com/b/ncdevguy/archive/2011/02/16/handy-links-for-hpc-and-azure.aspx 

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  • Google I/O 2011: High-performance GWT: best practices for writing smaller, faster apps

    Google I/O 2011: High-performance GWT: best practices for writing smaller, faster apps David Chandler The GWT compiler isn't just a Java to JavaScript transliterator. In this session, we'll show you compiler optimizations to shrink your app and make it compile and run faster. Learn common performance pitfalls, how to use lightweight cell widgets, how to use code splitting with Activities and Places, and compiler options to reduce your app's size and compile time. From: GoogleDevelopers Views: 4791 21 ratings Time: 01:01:32 More in Science & Technology

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  • Google I/O 2012 - Building High Performance Mobile Web Applications

    Google I/O 2012 - Building High Performance Mobile Web Applications Ryan Fioravanti Learn what it takes to build an HTML5 mobile app that will wow your users. This session will focus on speed, offline support, UI layouts, and the tools necessary to set up a productive development environment. Come to this session if you're looking to make a killer mobile web app that stands out amongst the competition. For all I/O 2012 sessions, go to developers.google.com From: GoogleDevelopers Views: 33 0 ratings Time: 49:43 More in Science & Technology

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  • Windows Azure Recipe: High Performance Computing

    - by Clint Edmonson
    One of the most attractive ways to use a cloud platform is for parallel processing. Commonly known as high-performance computing (HPC), this approach relies on executing code on many machines at the same time. On Windows Azure, this means running many role instances simultaneously, all working in parallel to solve some problem. Doing this requires some way to schedule applications, which means distributing their work across these instances. To allow this, Windows Azure provides the HPC Scheduler. This service can work with HPC applications built to use the industry-standard Message Passing Interface (MPI). Software that does finite element analysis, such as car crash simulations, is one example of this type of application, and there are many others. The HPC Scheduler can also be used with so-called embarrassingly parallel applications, such as Monte Carlo simulations. Whatever problem is addressed, the value this component provides is the same: It handles the complex problem of scheduling parallel computing work across many Windows Azure worker role instances. Drivers Elastic compute and storage resources Cost avoidance Solution Here’s a sketch of a solution using our Windows Azure HPC SDK: Ingredients Web Role – this hosts a HPC scheduler web portal to allow web based job submission and management. It also exposes an HTTP web service API to allow other tools (including Visual Studio) to post jobs as well. Worker Role – typically multiple worker roles are enlisted, including at least one head node that schedules jobs to be run among the remaining compute nodes. Database – stores state information about the job queue and resource configuration for the solution. Blobs, Tables, Queues, Caching (optional) – many parallel algorithms persist intermediate and/or permanent data as a result of their processing. These fast, highly reliable, parallelizable storage options are all available to all the jobs being processed. Training Here is a link to online Windows Azure training labs where you can learn more about the individual ingredients described above. (Note: The entire Windows Azure Training Kit can also be downloaded for offline use.) Windows Azure HPC Scheduler (3 labs)  The Windows Azure HPC Scheduler includes modules and features that enable you to launch and manage high-performance computing (HPC) applications and other parallel workloads within a Windows Azure service. The scheduler supports parallel computational tasks such as parametric sweeps, Message Passing Interface (MPI) processes, and service-oriented architecture (SOA) requests across your computing resources in Windows Azure. With the Windows Azure HPC Scheduler SDK, developers can create Windows Azure deployments that support scalable, compute-intensive, parallel applications. See my Windows Azure Resource Guide for more guidance on how to get started, including links web portals, training kits, samples, and blogs related to Windows Azure.

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