New Features
New session variable wsrep_sync_wait has been implemented to control causality check. The old session variable wsrep_causal_reads is deprecated but is kept for backward compatibility (#1277053).
systemd integration with RHEL/CentOS 7 is now available for Percona XtraDB Cluster (#1342223).
Bugs fixed
Percona XtraDB Cluster has implemented threadpool scheduling fixes. Bug fixed #1333348.
When gmcast.listen_addr was configured to a certain address, local connection point for outgoing connections was not bound to listen address. This would happen if OS has multiple interfaces with IP addresses in the same subnet, it may happen that OS would pick wrong IP for local connection point and other nodes would see connections originating from IP address which was not listened to. Bug fixed #1240964.
Client connections were closed unconditionally before generating SST request. Fixed by avoiding closing connections when wsrep is initialized before storage engines. Bug fixed #1258658.
Issue with re-setting galera provider (in wsrep_provider_options) has been fixed. Bug fixed #1260283.
Variable wsrep_provider_options couldn’t be set in runtime if no provider was loaded. Bug fixed #1260290.
Node consistency issues with foreign keys have been fixed. This fix introduces two new variables: wsrep_slave_FK_checks and wsrep_slave_UK_checks. These variables are set to TRUE and FALSE respectively by default. They control whether Foreign Key and Unique Key checking is done for applier threads. (#1260713).
When FLUSH TABLES WITH READ LOCK was used on a node with wsrep_causal_reads set to 1 while there was a DML on other nodes then, subsequent SELECTs/SHOW STATUS didn’t hang earlier providing non-causal output, that has been fixed here. Bug fixed #1271177.
Lowest group communication layer (evs) would fail to handle the situation properly when big number of nodes would suddenly start to see each other. Bugs fixed #1271918 and #1249805.
Updating a unique key value could cause server hang if slave node has enabled parallel slaves. Bug fixed #1280896.
Fixed the events replication inconsistencies. Bug fixed #1312618.
Truncating the sorted version of multi-byte character conversion could lead to wsrep certification failures. Bug fixed #1314854.
wsrep_slave_threads was counted towards max_connections which could cause ERROR 1040 (HY000): Too many connections error. Bug fixed #1315588.
Leaving node was not set nonoperational if processed leave message originated from different view than the current one which could cause other nodes to crash. Bug fixed #1323412 (#41).
garb couldn’t be started with init script on RHEL 6.5. Bug fixed #1323652.
SST would fail when binlogs were in dedicated directory that’s located inside datadir. This bug was a regression introduced by bug fix for #1273368. Bug fixed #1326012.
GTID of TOI operations is now also synced to InnoDB tablespace in order to get consistent backups. Bug fixed #1329055.
mysql-debug (UNIV_DEBUG) is now distributed with binary tar.gz along with RPM and DEB packages. Bug fixed #1332073.
Startup failure with Undetected state gap has been fixed. Bug fixed #1334606.
The restart sequence in scripts/mysql.server would fail to capture and return if the start call failed to start the server, so a restart could occur that failed upon start-up, and the script would still return 0 as if it worked without any issues. Bug fixed #1339894.
wsrep consistency check is now enabled for REPLACE ... SELECT as well. This was implemented because pt-table-checksum uses REPLACE .. SELECT during checksumming. Bug fixed #1343209.
A memory leak in wsrep_mysql_parse function has been fixed. Bug fixed #1345023.
SHOW STATUS was generating debug output in the error log. Bug fixed #1347818.
The netcat in garbd init script has been replaced with nmap for compatibility in CentOS 7. Bug fixed #1349384.
Fixed netcat in SST script for CentOS 7 nmap-ncat. Bug fixed #1359767.
percona-xtradb-cluster-garbd-3.x package was installed incorrectly on Debian/Ubuntu. Bugs fixed #1360633 and #1334530.
Other bugs fixed: #1334331, #1338995, #1280270, #1272982, #1190774, and #1251765.
