… innodb_write_io_threads = 16 innodb_purge_threads=1 innodb_adaptive_flushing=1 innodb_doublewrite=1 Please note that initially I used the default value for innodb_max_dirty… 5.5.8 by tuning innodb_max_dirty_pages_pct and innodb_io_capacity; but the limiting factor is still innodb_log_file_size…
Post: InnoDB Flushing: a lot of memory and slow disk
March 31, 2011 By 57 Comments
… of data, 12G innodb_buffer_pool_size, 1G innodb_log_file_size), MySQL 5.5.10 with innodb_adaptive_flushing=ON (default)). The problem… increase innodb_io_capacity and decrease innodb_max_dirty_pages_pct so as to have fewer dirty pages. But I call that tuning… jumps in flushing pages. Make the algorithm independent of innodb_io_capacity and innodb_max_dirty_pages_pct. (This is important for…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
… MySQL 5.6, no tuning at all Config 2: MySQL 5.6 with all default settings except innodb_old_blocks_time=0 Config… the defaults between MySQL 5.5 and MySQL 5.6 and innodb_old_blocks_time immediately came to mind. The InnoDB plugin introduced innodb… to the hot list. In MySQL 5.6 the default value of innodb_old_blocks_time is changed to 1000. The location…
Post: New SpecJAppServer results at MySQL and Sun.
November 12, 2008 By Leave a Comment
… this was really investigated. Indeed this is much smaller than default. If you have queries which only do small sorts it… number of threads inside Innodb Kernel. Again this is rather workload specific. innodb_sync_spin_loops = 40 – This tuning option is rarely used so I’m curious how much speed benefit did it really provide in this case. innodb_max…
Post: 5.0.75-build12 Percona binaries
January 23, 2009 By 18 Comments
….) * innodb_ibuf_accel_rate (default 100(%)) – This parameter is additional tuning the amount of insert buffer processing by background thread. Sometimes, only innodb_io_capacity is insufficient to tune the insert buffer. * innodb_ibuf_active_contract (default 0) – By default (same to normal InnoDB), the each…
Comment: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 12, 2013 By 7 Comments
… different. With the previous default it was useful to show benchmarks illustrating the value of setting innodb_old_blocks_pct to a non-zero value. Now we’ve changed the default it’s useful… help people to know that defaults can be tuned and when it might be a good idea. Defaults and general recommendations are good…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… with systems that are at any level of tuning, from completely untuned to a system that’s … that there are InnoDB tables whose .frm files exist but have been dropped from InnoDB, for example. (The … things I’ll look at, including checking for default users in the mysql.* tables, running mk-duplicate-…
Post: The performance effects of new patches
September 9, 2008 By 14 Comments
… some extreme cases, it is worth to tune. The following parameters are added. innodb_read_ahead (default 3) This controls [enable/disable] of… read-ahead only 0: disable both innodb_ibuf_contract_const (default 5) – Usual value innodb_ibuf_contract_burst (default 20) – Burst value The bigger…
Comment: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
… qc on. QC off tends to be best for well tuned OLTP and web sites using queries that mostly return a… most tables to be InnoDB and use innodb_file_per_table. sql_mode also uses STRICT_TRANS_TABLES by default. You were probably… because we don’t do it in the server defaults but in the default my.cnf file that we ship. It’s…
Post: table_cache negative scalability
November 16, 2009 By 23 Comments
… happening here. The “common sense” approach to tuning caches is to get them as large … on this test system as default sync_frm option is used. With default table_cache=64 accessing … indeed can cause significant performance problems. Interesting enough Innodb has a very similar task of managing …
