After several important fixes to our patches we made binaries for build12.
Control of InnoDB insert buffer to address problems Peter mentioned http://www.mysqlperformanceblog.com/2009/01/13/some-little-known-facts-about-innodb-insert-buffer/, also check Bug 41811 to see symptoms of problem with Insert buffer.
* innodb_flush_neighbor_pages (default 1) – When the dirty page are flushed (written to datafile), this parameter determines whether the neighbor pages in the datafile are also flushed at the same time or not. If you use the storage which don’t have â€œhead seek delayâ€ (e.g. SSD or enough Write-Buffered), 0 may show better performance. 0:disable, 1:enable
* innodb_ibuf_max_size (default [the half of innodb_buffer_pool_size](bytes)) – This parameter is startup parameter. If the lower value is set than the half of innodb_buffer_pool_size, it is used as maximum size of insert buffer. To restrict to the too small value (e.g. 0) is not recommended for performance. If you don’t like the insert buffer growing bigger, you should use the following parameters instead. (* If you use very fast storage, small value (like several MB) may show better performance.)
* 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 user threads do nothing about contracting the insert buffer until the insert buffer reaches its maximum size. 1 makes the each user threads positive to contract the insert buffer as possible in asynchronous.
Second important fix introduces variable use_global_long_query_time, which allows all current threads see change of long_query_time. By default value set in SET GLOBAL long_query_time=N command is visible only on new established connection, which is problem if you have pre-established connection pool, say in Java or Ruby on Rails application. With use_global_long_query_time=true even all current threads will respect SET GLOBAL long_query_time=N. The feature made for EngineYard, hosting provider for Ruby on Rails application.
You can download binaries (RPMS x86_64) and sources with patches here