Percona XtraDB Cluster 5.7.16-27.19¶
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 27
All Percona software is open-source and free. Details of this release can be found in the 5.7.16-27.19 milestone on Launchpad.
The following encryption modes:
The default is
encrypt=0with 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
3will soon be 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 maintenace 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.
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 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.
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 get rejected by newer clients with
dh key too smallerror.
For more information, see #1620439.
PXC-732: Improved error message when any of the SSL files required for SST are missing.
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).