tag:blogger.com,1999:blog-14455177.post4600514692977870612..comments2024-03-07T18:57:25.977+01:00Comments on Mikael Ronstrom: LOCK_open finally removed as a bottleneck in MySQL 5.6Mikael Ronstromhttp://www.blogger.com/profile/07134215866292829917noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-14455177.post-81572349629418397842012-10-08T10:54:21.719+02:002012-10-08T10:54:21.719+02:00The 70% speedup was a standard Sysbench RO and RW ...The 70% speedup was a standard Sysbench RO and RW benchmark using 2 tables.<br /><br />Given that each query in MySQL 5.5 grabs the LOCK_open once on start of query and once on end of query (actually once per table in the query). The operations that are affected are mainly queries that are short and where the server is hit by very many small queries. When the number of queries goes beyond 100k per second the lock becomes hotter and hotter. In previous generations of MySQL one could also get the problem very easily by setting the table cache to be too small.Mikael Ronstromhttps://www.blogger.com/profile/07134215866292829917noreply@blogger.comtag:blogger.com,1999:blog-14455177.post-8314961738906931862012-09-18T23:26:27.688+02:002012-09-18T23:26:27.688+02:00Anonymous,
This is a great improvement . one of t...Anonymous,<br /><br />This is a great improvement . one of the worst case is dropping a huge partition or a big table on a slow file system. A less seen isl scaleup issue when 100K queries all asking for a file descriptor in the various table caches. <br /><br />Thanks Michael and your team for taking that topic to a source code implementation.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-14455177.post-23651233776507219652012-06-06T09:13:30.859+02:002012-06-06T09:13:30.859+02:00Nice!
Can you detail a bit more
- which operation...Nice!<br /><br />Can you detail a bit more<br />- which operations are typically affected by this lock<br />- which benchmark got a 70% improvement?Anonymousnoreply@blogger.com