Percona XtraDB Cluster 5.7.16-27.19 is now the current release, based on the following:
- Percona Server 5.7.16-10
- Galera Replication library 3.19
- wsrep API version 26
All Percona software is open-source and free.
- The following encryption modes are now deprecated:
The default is
encrypt=0 with encryption disabled. The recommended mode now is the new
encrypt=4, which uses SSL files generated by MySQL.
For more information, see Encrypting PXC Traffic.
encrypt=4mode for SST encryption that uses SSL files generated by MySQL. Modes
3are now deprecated.
- ProxySQL assisted maintenance mode that enables you to take a node down without adjusting ProxySQL manually. The mode is controlled using the
pxc_maint_modevariable, which can be set to one of the following values:
DISABLED: This is the default state that tells ProxySQL to route traffic to the node as usual.
SHUTDOWN: This state is set automatically when you initiate node shutdown.
MAINTENANCE: You can change to this state if you need to perform maintenance on a node without shutting it down.
For more information, see Assisted Maintenance Mode.
- Simplified SSL configuration for Galera/SST traffic with
pxc-encrypt-cluster-trafficoption, which auto-configures SSL encryption.
For more information, see SSL Automatic Configuration.
- Added the
wsrep_flow_control_intervalstatus variable that displays the lower and upper limits of the flow control system used for the Galera receive queue.
- Optimized IST donor selection logic to avoid SST. Child processes are now cleaned-up and node state is resumed if SST fails.
init.okto the list of files that do not get removed during SST.
- Fixed error with ASIO library not acknowledging an
EPOLLINevent when building Galera.
- Fixed stalling of DML workload on slave node caused by
FLUSH TABLEexecuted on the master.
For more information, see 1629296.
super_read_onlyto not apply to Galera replication applier.
For more information, see 1634295.
stdoutto avoid it in the log.
For more information, see 1625968.
- Enabled replication of
For more information, see 1376269.
- Changed the
wsrep_max_ws_rowsvariable to ignore non-replicated write-sets generated by DML action on temporary tables (explict or implicit).
For more information, see 1638138.
- Fixed SST to fail with an error if SSL is not supported by
socat, instead of switching to unencrypted mode.
- Fixed SST with SSL to auto-generate a 2048-bit
dhparamsfile for versions of
socatbefore 1.7.3. These older versions use 512-bit
dhparamsfile by default that gets rejected by newer clients with
dh key too smallerror.
- PXC-731: Changed the
wsrep_cluster_namevariable to read-only, because changing it dynamically leads to high overhead.
For more information, see 1620439.
- PXC-732: Improved error message when any of the SSL files required for SST are missing.
- PXC-735: Fixed SST to fail with an error when
netcatis used (
transferfmt=nc) with SSL encryption (
4), instead of silently switching to unencrypted mode.
- Fixed faulty switch case that caused cluster to stall when the
repl.commit_ordervariable was set to
LOCAL_OOOCmode that should allow out-of-order committing for local transactions).
Help us improve our software quality by reporting any bugs you encounter using our bug tracking system. As always, thanks for your continued support of Percona!