Improved Cloud (WAN) performance with Galera Cluster MySQL 5.6.47 and 5.7.29

Codership is pleased to announce a new Generally Available (GA) release of Galera Cluster for MySQL 5.6 and 5.7, consisting of MySQL-wsrep 5.6.47 (release notes, download) and MySQL-wsrep 5.7.29 (release notes, download) with a new Galera Replication library 3.29 (release notes, download), implementing wsrep API version 25. This release incorporates all changes to MySQL 5.6.47 and 5.7.29 respectively.

A highlight for improved WAN performance (great for cloud environments, well-tuned networks will perform faster) in Galera Replication library 3.29 is there is a new setting for socket.recv_buf_size set to auto which allows the underlying kernel (be it on Linux or FreeBSD) to tune the TCP receive buffer. A new socket.send_buf_size exists now, defaulting to auto but allows tuning of the send buffer.

The Galera Replication library compared to the previous 3.29 release has a few new enhancements: when the Group Communication System (GCS) library would get JOIN messages even if the node was in a DONOR state has been fixed. GCache could occasionally have different histories from different clusters has been fixed. Reliability of time-stamping and liveness checking of connections between cluster nodes was improved to eliminate false positives especially during the replication of large transactions, with segmentation configured; delivery latency of relayed messages between segments was improved by introducing fair queuing of the outbound message. The communications protocol around the GComm EVS (Extended Virtual Synchrony) layer now uses point-to-point messaging to deliver missing messages and there is rate limiting on retransmission requests. Quorum computation was hardened to maintain consistency during rapid configuration changes.

MySQL 5.6.47 with Galera Replication library 3.29 is an updated rebase which can be considered a maintenance release.

MySQL 5.7.29 with Galera Replication library 3.29 is an updated rebase, which can mostly be considered a maintenance release. It does fix a notable issue since the last release, in where there was an occasional hang during server shutdown due to an occasional race condition received from a client connection stuck waiting for a network event.

You can get the latest release of Galera Cluster from There are package repositories for Debian, Ubuntu, CentOS, RHEL, OpenSUSE and SLES. The latest versions are also available via the FreeBSD Ports Collection.

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