New Features
wsrep patch did not allow server to start with Query Cache enabled. This restriction and check have been removed now and query cache can be fully enabled from config file.
New SST options have been implemented: inno-backup-opts, inno-apply-opts, inno-move-opts which pass options to backup, apply and move stages of innobackupex.
The joiner would wait and not fall back to choosing other potential donor nodes (not listed in wsrep_sst_donor) by their state. This happened even when comma was added at the end. This fixes it for that particular case. Bug fixed #1285380.
Initial configurable timeout, of 100 seconds, to receive a first packet via SST has been implemented, so that if donor dies somewhere in between, joiner doesn’t hang. Timeout can be configured with the sst-initial-timeout variable.
Bugs fixed
Replication of partition tables without binlogging enabled failed, partition truncation didn’t work because of lack of TO isolation there. Bug fixed #1219605.
Using LOAD DATA INFILE in with autocommit set to 0 and wsrep_load_data_splitting set to ON could lead to incomplete loading of records while chunking. Bug fixed #1281810.
Garbd could crash on CentOS if variable gmcast.listen_addr wasn’t set. Bug fixed #1283100.
Node couldn’t be started with wsrep_provider_options option debug set to 1. Bug fixed #1285208.
Boostrapping a node in a NON-PRIMARY state would lead to crash. Bug fixed #1286450.
New versions of xtrabackup SST scripts were ignoring --socket parameter passed by mysqld. Bug fixed #1289483.
Regression in Galera required explicitly setting socket.ssl to Yes even if you set up variables socket.ssl_key and socket.ssl_cert. Bug fixed #1290006.
Fixed the clang build issues that were happening during the Galera build. Bug fixed #1290462.
Better diagnostic error message has been implemented when wsrep_max_ws_size limit has been succeeded. Bug fixed #1280557.
Fixed incorrect warnings and implemented better handling of repeated usage with same value for wsrep_desync. Bug fixed #1281696.
Fixed the issue with wsrep_slave_threads wherein if the number of slave threads was changed before closing threads from an earlier change, it could increase the total number of threads beyond value specified in wsrep_slave_threads. Bug fixed #1290612
A regression in mutex handling caused dynamic update of wsrep_log_conflicts to hang the server. Bug fixed #1293624.
Presence of /tmp/test directory and an empty test database caused Percona XtraBackup to fail, causing SST to fail. This has been fixed in Percona XtraDB Cluster’s xtrabackup SST script, by using unique temporary directories with Percona XtraBackup. Bug fixed #1294760.
After installing the auth_socket plugin any local user might get root access to the server. If you’re using this plugin upgrade is advised. This is a regression, introduced in Percona XtraDB Cluster 5.6.14-25.1. Bug fixed #1289599
Other bug fixes: #1289776, #1279343, #1259649, #1292533, #1272982, #1287098, and #1284670.