… over multiple ports, and with a two-NIC bonded pair you’ll get roughly 1.67x the throughput of a single port…’s worse than a single NIC.] The other two NIC ports should be bonded with active-backup or LACP (depending on your… of long-running queries in the output of SHOW PROCESSLIST that might be a sign that trouble is brewing. Or if you…
Post: Why MySQL Performance at Low Concurrency is Important
March 27, 2013 By 8 Comments
…response times (MySQL server does not use multiple threads to execute query in parallel at this point). …many batch jobs are written to be single-threaded. MySQL replication is single-thread too, and MySQL 5….wild have Threads_running on average of 5 or less, at least the system is performing well…
Post: How multiple disks can benefit for single client workload ?
April 26, 2008 By 4 Comments
… original article I mentioned having multiple hard drives does not help if you have single query (or stream of queries) which you need to deal… first look how single query is executed for Innodb storage engine to be more specific. Lets look at update queries (from replication thread…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 23 Comments
… helps improve the performance of queries against a MySQL database by distributing the work over multiple machines and/or multiple cores. This is similar… will be described in another post. Complex queries Shard-Query was tested with the simple single table version of this data set in…
Post: Making MySQL Replication Parallel
January 30, 2007 By 1 Comment
… deadlocks between queries if they are complex transactions. It should be however not as bad if we only look at single queries or transactions which do not have any overlap in terms of tables. For some users commit order for independent queries may…, such as reading or writing to the same tables. There is other possible solution it is to allow multiple threads inside the…
Post: Using flow control functions for performance monitoring queries
May 24, 2008 By 12 Comments
… IF statement very useful is computing multiple aggregates over different set of rows in the single query sweep. Here is how I like… request time as well as classifies requests to multiple classes. From the same query we can see portion of requests which were… set performance goals for high percentage portion such as – 95% or 99% and see what fraction of requests matches this goal…
Comment: The #1 mistake hosting providers make for MySQL servers
August 1, 2008 By 30 Comments
… using MySQL! Joking aside: MySQL doesn’t parallelize a single query across multiple cores. If you want help getting better performance out of… to help: submit the contact form on www.percona.com. Or you can just buy our book. There’s a link…
Post: Using Multiple Key Caches for MyISAM Scalability
November 26, 2008 By 8 Comments
… also use multiple Key Caches to reduce or virtually eliminate key cache contention. Too bad you can only map single table to single key cache – it would be so much more helpful if you could use multiple key caches… min 23.67 sec) A bit more query hacking and we get a query which will return statements to initialize key buffers…
Post: Fighting MySQL Replication Lag
September 22, 2008 By 7 Comments
… remember is MySQL Replication is single threaded, which means if you have any long running write query it clogs replication stream and… long running updates. Queries or transactions containing multiple update queries which add up to long time. I would keep the maximum query length at about…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 141 Comments
…multiple drives do not really help a lot as we’re speaking about single thread/query… normalized to several tables or perform complex queries finding relationships between objects. …single query runs as single thread (with exeption of MySQL Cluster) and MySQL issues IO requests one by one for query…
