…: ## InnoDB options innodb_buffer_pool_size = 55G innodb_log_file_size = 1G innodb_log_files_in_group = 4 innodb_buffer_pool_instances = 4 innodb_… having multiple buffer pool instances to reduce contention problems caused by buffer pool mutexes, using “estimate” checkpoint method to reduce chances …
Post: kernel_mutex problem. Or double throughput with single variable
December 2, 2011 By 17 Comments
…_mutex (and all InnoDB mutexes) has complex handling with spin loops, and there are two variables that affects mutex loops: innodb_sync_spin_loops and innodb… ways to deal with problem when you hit by kernel_mutex problem. Further direction I want to try to limit innodb_thread_concurrency and…
Post: kernel_mutex problem cont. Or triple your throughput
December 2, 2011 By 10 Comments
… post with kernel_mutex problem. First, I may have an explanation why the performance degrades to significantly and why innodb_sync_spin_loops… some benchmarks with innodb_thread_concurrency. My explanation on the performance degradation is following: InnoDB still uses some strange mutex implementation, based on… is possible only because InnoDB is still Open Source and we all can check source code. If the problem were in the…
Post: Internals of InnoDB mutexes
September 7, 2006 By 4 Comments
…, but InnoDB‘s implementation isn’t ideal and on modern SMP boxes can cause serious performance problems. Let’s look on InnoDB mutex (schematic for simplification): spin_loop: for (i=0; i< innodb_spin_locks;i++) if (mutex_try…
Post: MyISAM Scalability and Innodb, Falcon Benchmarks
October 12, 2007 By 10 Comments
We many times wrote about InnoDB scalability problems, this time We are faced with one for MyISAM tables. … 40% of effective CPU time is spent in pthread_mutex_lock / pthread_mutex_unlock. We could not get oprofile call tree to… only guess where these mutex lock requests come from. A second confirmation that key_cache is a problem is benchmark run with…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
… of little known aspects of Innodb operations while I see it causing problems every so often. Q16: How Innodb decided how many pages… often solves your thrashing problem. PZ: Values 1,2 may solve your thrashing problem but also will limit innodb to be able to… Golubchik serialized the MySQL binlog write and the InnoDB log flush with a mutex in 5.1, to implement XA, and switching…
Post: InnoDB benchmarks
January 3, 2007 By 15 Comments
…. Problems in InnoDB that were fixed: Thread trashing issues with count of theads 100+. In this case performance of InnoDB degraded dramatically. The problem was in the mutex impelementation and was fixed in 5.1.12 (more info about InnoDB mutexes) Scalabilty…
Post: InnoDB, InnoDB-plugin vs XtraDB on fast storage
January 13, 2010 By 12 Comments
… for InnoDB-plugin. Here we observe innodb_adaptive_flushing in action (which is ON by default), and I think innodb_adaptive_flushing in InnoDB… later), I guess InnoDB-plugin spends most time in buffer_pool mutex, contention here is not fully resolved yet in InnoDB-plugin. Now… InnoDB-plugin, I’d wish InnoDB team makes some actions on buffer_pool mutex problem. Finally I wanted to check what if we put innodb…
Post: My Innodb Feature wishes
May 4, 2006 By 30 Comments
… times space compression. Insert buffer for delete. For Insert operation Innodb uses nice tecnique called Insert Buffer which speeds up inserts… it is so bad I will list it. Basically Innodb has problems scaling both with large number of active threads and with… with 4 concurrent queries). The problem seems to be at least partially due to global mutexes in many places so it is…
Post: InnoDB vs MyISAM vs Falcon benchmarks - part 1
January 8, 2007 By 117 Comments
… MyISAM / InnoDB: libexec/mysqld –no-defaults –user=root –key-buffer-size=1500M –innodb-buffer-pool-size=1500M –innodb-log-file-size=100M –innodb-thread… does not scale good enough. Perhaps there is still a problem with InnoDB mutexes. READ_KEY_POINT_NO_DATA Query: SELECT state_id…
