Based on MySQL 5.6.15, including all the bug fixes in it, Percona Server 5.6.15-63.0 is the current GA 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 5.6.15-63.0 milestone at Launchpad.
Percona Server has extended mysqlbinlog to provide SSL and compression support.
Percona Server has reduced the performance overhead of the User Statistics feature.
Certain types of workloads (large result sets, blobs, slow clients) can have longer waits on network I/O (socket reads and writes). Whenever server waits, this should be communicated to the Thread Pool, so it can start new query by either waking a waiting thread or sometimes creating a new one. Ported MariaDB patch MDEV-156, bug fixed #1159743.
mysqldump --innodb-optimize-keys was generating incorrect CREATE TABLE statements for partitioned tables. Bug fixed #1233841.
Fixed errors when server was compiled with -DWITH_LIBWRAP=ON option. Bug fixed #1240442.
If innobase_atomic_writes was used on separate undo files that do not exists would lead to operating system error. Bug fixed #1255638 (Jan Lindström).
Default value for thread_pool_max_threads has been changed from 500 to 100 000 (the maximum supported number of connections), because limiting the total number of threads in the Thread Pool can result in deadlocks and uneven distribution of worker threads between thread groups in case of stalled connections. Bug fixed #1258097.
PURGE CHANGED_PAGE_BITMAPS BEFORE statement would delete the changed page data after the specified LSN and up to the start of the next bitmap file. If this data were to be used for fast incremental backups, its absence would cause Percona XtraBackup to fall back to the full-scan incremental backup mode. Bug fixed #1260035 (Andrew Gaul).
Server performance could degrade under heavy load or it could deadlock on shutdown while performing purge. Bug fixed #1236696.
Server could crash under heavy load if InnoDB compression was used. Bug fixed #1240371.
Redo log checksum mismatches would be diagnosed using the data page checksum algorithm setting instead of redo log checksum algorithm one. Bug fixed #1250148.