… what’s seriously limiting MySQL in certain circumstances (links: part 1). In the first part, I wrote about single-threaded replication. Upstream from… data in the server. The binary log is a real limitation in MySQL. The binary log is necessary not only for replication… transaction logs, so there’s even precedent for this among MySQL storage engines. And there is Galera’s multi-master synchronization…
Post: MySQL on Amazon RDS part 1: insert performance
March 15, 2011 By 37 Comments
… Service (RDS) is a cloud-hosted MySQL solution. I’ve had some clients hitting performance limitations on standard EC2 servers with EBS…, I thought it would be interesting to measure the single-threaded insert throughput as sysbench ran the “prepare” phase and filled… see that it would really benefit them. Finally, a single-threaded insert workload is not very revealing. To understand the sustained…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 141 Comments
… over 300.000 of random lookups per second from single thread depending on system and table structure. Now if you data… more MySQL limitation which requires you to be extra careful working with large data sets. In MySQL single query runs as single thread (with exeption of MySQL Cluster) and MySQL issues IO requests one by…
Post: Profiling MySQL Memory Usage With Valgrind Massif
January 9, 2013 By 3 Comments
… complaining quickly. If you self compile, and those Valgrind-internal limits are still too small, you can easily change them before… (in /usr/local/percona/mysql-5.5.28/usr/sbin/mysqld) | | | ->10.10% (7,135,744B) 0x3ECF60677B: start_thread (in /lib64/libpthread… (in /usr/local/percona/mysql-5.5.28/usr/sbin/mysqld) | | | ->27.73% (114,084,096B) 0x3ECF60677B: start_thread (in /lib64/libpthread…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
…variable which allows you to limit size of MEMORY tables (the limit applies both to … (318747272 + 128560) Recovery system 0 (0 + 0) Threads 425080 (406936 + 18144) Dictionary memory allocated … is where your MySQL Support contract can be handy. Conclusion Understanding where MySQL can allocate …
Post: Is your MySQL Application having Busy IO by Oracle Measures ?
January 8, 2012 By 1 Comment
… external storage. 500MB/sec would be exceptional for traditional MySQL as MySQL optimizer with its nested loops joins does not favor sequential… I believe is ability of MySQL to use powerful system (including powerful storage) – Is quite limited with single thread replication as well as…
Post: Product to try: MySQL/MariaDB-Galera 0.8
June 13, 2011 By 34 Comments
…not agree with that ) with some serious limitations (like using mysqldump for node propagation). …the XtraDB storage engine. Support for multi-threaded slaves. Using custom scripts for node propagation….is much more complex than an average MySQL master-slave setup. Potential performance penalty: …
Post: How to debug long-running transactions in MySQL
March 8, 2011 By 6 Comments
… query the tables, and if something is blocked, find its thread ID. Match this up with the ID in SHOW PROCESSLIST… INNER JOIN information_schema.processlist p on b.trx_mysql_thread_id = p.ID LIMIT 1′) if [ "${host}" ]; then echo “Host ${host} is… port 3306 and port ${port} > /root/tcpdumps/`date +%s`-tcpdump & mysql -e ‘show innodb status\Gshow full processlist’ > /root/tcpdumps/`date +%s…
Post: Is there room for more MySQL IO Optimization?
January 3, 2013 By 11 Comments
… double buffering and I can save the limited amount of file system cache I would …, binary log, FRM files, MySQL MyISAM system tables etc. Starting MySQL 5.5 MySQL uses asynchronous IO which … Architecture | CPU = 64-bit, OS = 64-bit Threading | NPTL 2.15 SELinux | No SELinux detected Virtualized …
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…, process no 3396, OS thread id 1148250464, thread declared inside InnoDB 442 mysql tables in use 1, locked 0 MySQL thread id 8079, query id… tries to limit thread concurrency allowing only innodb_thread_concurrency threads to run inside Innodb kernel at the same time. If thread is not runniing…
