New Features
Complete list of changes between Percona Server 5.6 and 5.7 can be seen in Changed in Percona Server 5.7.
Percona Server has implemented Multi-threaded asynchronous LRU flusher. This work also allows to safely use backoff value for the innodb_empty_free_list_algorithm server system variable, and its default has been changed accordingly.
Known Issues
In Percona Server 5.7 super_read_only feature has been replaced with upstream implementation. There are currently two known issues compared to Percona Server 5.6 implementation:
Bug #78963, super_read_only aborts STOP SLAVE if variable relay_log_info_repository is set to TABLE which could lead to a server crash in Debug builds.
Bug #79328, super_read_only set as a server option has no effect.
InnoDB crash recovery might fail if innodb_flush_method is set to ALL_O_DIRECT. The workaround is to set this variable to a different value before starting up the crashed instance (bug #1529885).
Bugs Fixed
Percona Server 5.7.10-1 didn’t write the initial root password into the log file /var/log/mysqld.log during the installation on CentOS 6. Bug fixed #1541769.
Cardinality of partitioned TokuDB tables became inaccurate after the changes introduced by TokuDB Background ANALYZE TABLE feature in Percona Server 5.7.10-1. Bug fixed #925.
Running the TRUNCATE TABLE while TokuDB Background ANALYZE TABLE is enabled could lead to a server crash once analyze job tries to access the truncated table. Bug fixed #938.
Percona TokuBackup would fail with an unclear error if backup process found mysqld_safe.pid file (owned by root) inside the datadir. Fixed by excluding the pid file by default. Bug fixed #125.
PAM Authentication Plugin build warning has been fixed. Bug fixed #1541601.
