… completed? HT: A query thread normally posts about 64 page read requests per a readahead. The InnoDB buffer is 256 page read requests for the aio read thread. Thus, about 4 readaheads can… different applications work best on different database brands. Oracle’s main database has a very competent team working on it. Q29…
Post: The relationship between Innodb Log checkpointing and dirty Buffer pool pages
February 17, 2012 By 10 Comments
… log if you set this too high. innodb_write_io_threads: Controls how many threads will have writes in progress to the disk… one thread (particularly if you have relatively few tables and/or use the global tablespaces) *cough ext3 cough*. innodb_adaptive_flushing: An Innodb… just a hair under the Max Checkpoint age). The two main methods here would be ‘estimate’ (good default) and ‘keep_average…
Post: Introducing percona-patches for 5.1
February 9, 2010 By 21 Comments
… what Flickr had to say on their blog. The main improvements come in both performance gains and improvements to diagnostics… on product for some customer’s policies. Important fixes are: – InnoDB IO threads – Adaptive checkpointing – Buffer pool mutex split – Reimplemented read-write…
Post: Recovery deleted ibdata1
August 10, 2012 By 9 Comments
… when a customer deleted the InnoDB main table space – ibdata1 – and redo logs – ib_logfile*. MySQL keeps InnoDB files open all the time… ensure InnoDB isn’t doing any writes: FILE I/O ——– I/O thread 0 state: waiting for i/o request (insert buffer thread… thread) I/O thread 2 state: waiting for i/o request (read thread) I/O thread 3 state: waiting for i/o request (write thread…
Post: MyISAM Scalability and Innodb, Falcon Benchmarks
October 12, 2007 By 10 Comments
… second than identical box, but with 4 CPU Cores. The main query which showed this problem was similar to this: SELECT… table t1 into InnoDB, and results: Threads Queries/sec 1 296 2 341 4 544 8 493 16 498 InnoDB both performs much… MyISAM and 1/6th of Innodb. On other hand it scales quite nicely as number of threads increase. The interesting thing is…
Post: XtraDB/InnoDB CPU bound benchmarks on 24cores server
December 29, 2008 By 6 Comments
… doing internal QA for, but it will be ready soon. Main difference XtraDB-rel2 it contains additional scalability fixes for buffer…_group=2 innodb_log_file_size=512M innodb_status_file=0 innodb_thread_concurrency=0 innodb_io_capacity=1000 innodb_write_io_threads = 16 innodb_read_io_threads = 16…
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…-innodb and next startup options were used: libexec/mysqld –no-defaults –user=root –innodb-buffer-pool-size=1500M –innodb-log-file-size=100M –innodb-thread… show the scalability problem, but the main goal was the comparison of overall performance of InnoDB before fix (in 5.0.27…
Post: Improved InnoDB rw_lock patch
October 20, 2008 By 3 Comments
… for 4+ threads we have worse results than for 2 threads. That is was main reason why we did not include InnoDB smp fixes… results comparable with Google’s smpfix, so we will include innodb_rw_lock into our next -percona-highperf release
Post: Internals of InnoDB mutexes
September 7, 2006 By 4 Comments
… instead of POSIX-mutexes pthread_mutex*, the main reason for that is performance, but InnoDB‘s implementation isn’t ideal and on… variable innodb_sync_spin_loops (default value is 20) There we have: 1. Spin-loop – InnoDB uses spin-loop in hopes thread locked mutex is very fast and will release mutex while current thread runs in…
Post: InnoDB compression woes
May 20, 2011 By 14 Comments
…_prepare.lua –oltp-tables-count=16 –num-threads=16 –oltp-table-size=25000000 run Results: … we have some mutex serialization problem. Analyzing SHOW INNODB STATUS (SEMAPHORES) for workload with compression tables … workload (this is where they should give main benefit), but for in-memory load it …
