This release is based on MySQL 5.7.25 and includes all the bug fixes in it. Percona Server 5.7.25-28 is now the current GA (Generally Available) release in the 5.7 series.
All software developed by Percona is open-source and free.
In this release, Percona Server introduces the variable binlog_skip_flush_commands. This variable controls whether or not FLUSH commands are written to the binary log. Setting this variable to ON can help avoid problems in replication. For more information, refer to our documentation.
If you’re currently using Percona Server 5.7, Percona recommends upgrading to this version of 5.7 prior to upgrading to Percona Server 8.0.
FLUSH commands written to the binary log could cause errors in case of replication. Bug fixed #1827: (upstream #88720).
Running LOCK TABLES FOR BACKUP followed by STOP SLAVE SQL_THREAD could block replication preventing it from being restarted normally. Bug fixed #4758.
The ACCESS_DENIED field of the information_schema.user_statistics table was not updated correctly. Bug fixed #3956.
MySQL could report that the maximum number of connections was exceeded with too many connections being in the CLOSE_WAIT state. Bug fixed #4716 (upstream #92108)
Wrong query results could be received in semi-join sub queries with materialization-scan that allowed inner tables of different semi-join nests to interleave. Bug fixed #4907 (upstream bug #92809).
In some cases, the server using the the MyRocks storage engine could crash when TTL (Time to Live) was defined on a table. Bug fixed #4911
Running the SELECT statement with the ORDER BY and LIMIT clauses could result in a less than optimal performance. Bug fixed #4949 (upstream #92850)
There was a typo in mysqld_safe.sh: trottling was replaced with throttling. Bug fixed #240. Thanks to Michael Coburn for the patch.
MyRocks could crash while running START TRANSACTION WITH CONSISTENT SNAPSHOT if other transactions were in specific states. Bug fixed #4705,
In some cases, mysqld could crash when inserting data into a database the name of which contained special characters (CVE-2018-20324). Bug fixed #5158.
MyRocks incorrectly processed transactions in which multiple statements had to be rolled back. Bug fixed #5219.
In some cases, the MyRocks storage engine could crash without triggering the crash recovery. Bug fixed #5366.
[*]When bootstrapped with undo or redo log encryption enabled on a very fast storage, the server could fail to start. Bug fixed #4958.
Other bugs fixed: #2455, #4791, #4855, #4996, #5268.
This release also contains fixes for the following CVE issues: CVE-2019-2534, CVE-2019-2529, CVE-2019-2482, CVE-2019-2434.