Based on MySQL 5.6.13, including all the bug fixes in it, Percona Server 5.6.13-60.6 is the fourth RC release in the Percona Server 5.6 series. All of Percona‘s software is open-source and free, all the details of the release can be found in the 5.6.13-60.6 milestone at Launchpad.
Improved Buffer Pool Scalability feature has been ported from Percona Server 5.5. This feature splits the single global InnoDB buffer pool mutex into several mutexes. The goal of this change is to reduce mutex contention, which can be very impacting when the working set does not fit in memory.
Multiple Adaptive Hash Search Partitions feature has been ported from Percona Server 5.5. This feature splits the adaptive hash index across several partitions and decreases the AHI latch contention. This feature fixes the upstream bug #62018 (#1216804).
Percona Server now provides additional information in the slow query log when log_slow_rate_limit variable is enabled.
A new variable slow_query_log_always_write_time has been introduced. It can be used to specify an additional execution time threshold for the slow query log, that, when exceeded, will cause a query to be logged unconditionally, that is, log_slow_rate_limit will not apply to it.
The unnecessary overhead from persistent InnoDB adaptive hash index latching has been removed, potentially improving stability of the Multiple Adaptive Hash Search Partitions feature as well. Upstream bug fixed #70216, bug fixed #1218347.
Adaptive hash indexing partitioning code has been simplified, potentially improving performance. Bug fixed #1218321.