Percona XtraDB Cluster 5.7.17-29.20

Percona is glad to announce the release of Percona XtraDB Cluster 5.7.17-29.20 on April 19, 2017. Binaries are available from the downloads section or from our software repositories.

Percona XtraDB Cluster 5.7.17-29.20 is now the current release, based on the following:

All Percona software is open-source and free.

Performance Improvements

This release was focused on performance and scaling capability with increasing workload threads. Tests show up to 10 times increase in performance.

Fixed Bugs

  • Improved parallelism for better scaling with multiple threads.
  • Updated semantics for gcache page cleanup to trigger when either gcache.keep_pages_size or gcache.keep_pages_count exceeds the limit, instead of both at the same time.
  • Improved SST and IST log messages for better readability and unification.
  • Excluded the garbd node from flow control calculations.
  • Added extra checks to verify that SSL files (certificate, certificate authority, and key) are compatible before opening connection.
  • Added validations for DISCARD TABLESPACE and IMPORT TABLESPACE in PXC Strict Mode to prevent data inconsistency.
  • Added support for passing the XtraBackup buffer pool size with the use-memory option under [xtrabackup] and the innodb_buffer_pool_size option under [mysqld] when the --use-memory option is not passed with the inno-apply-opts option under [sst].
  • Added the wsrep_flow_control_status variable to indicate if node is in flow control (paused).
  • Fixed gcache page cleanup not triggering when limits are exceeded.
  • PXC-766: Added the wsrep_ist_receive_status variable to show progress during an IST.
  • Allowed CREATE TABLE ... AS SELECT (CTAS) statements with temporary tables (CREATE TEMPORARY TABLE ... AS SELECT) in PXC Strict Mode. For more information, see #1666899.
  • PXC-782: Updated xtrabackup-v2 script to use the tmpdir option (if it is set under [sst], [xtrabackup] or [mysqld], in that order).
  • PXC-783: Improved the wsrep stage framework.
  • PXC-784: Fixed the pc.recovery procedure to abort if the gvwstate.dat file is empty or invalid, and fall back to normal joining process. For more information, see #1669333.
  • PXC-794: Updated the sockopt option to include a comma at the beginning if it is not set by the user.
  • PXC-795: Set --parallel=4 as default option for wsrep_sst_xtrabackup-v2 to run four threads with XtraBackup.
  • PXC-797: Blocked wsrep_desync toggling while node is paused to avoid halting the cluster when running FLUSH TABLES WITH READ LOCK. For more information, see #1370532.
  • PXC-805: Inherited upstream fix to avoid using deprecated variables, such as INFORMATION_SCHEMA.SESSION_VARIABLE. For more information, see #1676401.
  • PXC-811: Changed default values for the following variables:
    • fc_limit from 16 to 100
    • send_window from 4 to 10
    • user_send_window from 2 to 4
  • Moved wsrep settings into a separate configuration file (/etc/my.cnf.d/wsrep.cnf).
  • Fixed mysqladmin shutdown to correctly stop the server on systems using systemd.
  • Fixed several minor packaging and dependency issues.