… of buf_get_latched_pages_number being responsible for most CPU usage. It did not look right. The close look revealed this… mutex. Another function which we’ve seen being responsible for high CPU usage is ha_print_info which also may traverse large arrays… for MySQL 5.0 compared to MySQL 4.1 It was something like 2-3 for MySQL 4.1 vs 40-60 for MySQL…
Post: How Innodb Contention may manifest itself
July 28, 2011 By 1 Comment
… happens user CPU will be very high, and the context switches will be somewhere reasonable. In others you would see the CPU usage being low with a lot of CPU being idle, increased compared to normal workload portion of system CPU and high number… time while you’re upgrading to Percona Server or newer MySQL version or doing application/architecture changes. Reducing number of competing…
Post: MySQL caching methods and tips
April 4, 2011 By 5 Comments
…MySQL. Popular cache methods The MySQL query cache When the query cache is enabled, MySQL… On servers with many cores, a high volume of queries can cause extensive…CPU usage. Disk IO is expensive, and even if the disk bottleneck is eliminated, the sorting, aggregation and join operations are still CPU…
Post: Drilling down to the source of the problem
November 8, 2008 By 7 Comments
… at the same time there was no significant iowait, neither high CPU usage. Closer examination showed there were hundreds of queries stuck in… excuse to blame everything on this lock, suggest upgrading to MySQL 5.1 and call it a day. Learning more about… internal contention. In reality though this option best setting is highly application dependent and you should not blindly use somebody elses…
Comment: Bug fix of InnoDB scalability problem
February 12, 2007 By 13 Comments
… high CPU usage… Potential temporary solution in moving to MySQL 5.0.33 which has several performance enhancing benefits for innodb with dual core cpu…
Post: Infinite Replication Loop
October 10, 2011 By 2 Comments
… monitoring your MySQL server with cacti, you will immediately notice the problem. Look at those graphs: You can see the CPU usage and… passive to disable any automatic failover during the process because high availability tools like mmm can cause failover if you stop… wrong server-id are performed on the two slaves (mysql 3 and mysql 4) and the new events (with server-id 1…
Post: Predicting Performance improvements from memory increase
August 7, 2008 By 6 Comments
… way too much IO bound anyway. Interesting enough because of MySQL scaling issues it is also possible to see performance to… IO bound (high IO system utilization, low CPU usage) one should think about how much CPU capacity is available. If your CPU is 25% busy…% IO subsystem utilization on 5% of CPU usage ? This is the true challenge becomes because MySQL has no tools to analyze working set…
Post: MySQL extensions for hosting
April 24, 2008 By 11 Comments
… to a dedicated server because their usage is very high temporarily block users having huge spike in MySQL usage Personally I would see a few more things implemented. A few examples to mention: per-user CPU time usage, some queries may be CPU bound rather than reading lots of rows support…
Post: Impact of memory allocators on MySQL performance
July 5, 2012 By 11 Comments
… for the proper utilization of CPU/RAM resources. Efficient memory allocator …allocators on the performance/scalability of MySQL server in the read-only workloads… drops – almost two times at high threads. In the same time …server – more than on 5G. Memory usage for others allocators looks more or…
Comment: MySQL random freezes could be the query cache
March 29, 2009 By 23 Comments
… with MySQL 5.1.32. Its a pretty high traffic site, but I’ve never seen the DB server go above 20% CPU usage… it freezes up it’s top state shows “ucond” and cpu usage is 0% or very low so somehow its still doing…-resolve max_connections = 2000 skip-innodb log-bin = /usr/mysql/logs/mysql-bin.log binlog-do-db=tp server-id=1 wait…
