codership-mysql

codership-mysql contains write set replication patches for MySQL maintained by Codership team.

This patch implements hooks inside MySQL/Innodb engine, which can be used to build external replication system for MySQL servers. The replication system built on these hooks can be asynchronous or synchronous and have single or multi-master support.

The replication hooks provide management of transaction write sets:

* populating of write sets, in the sending side
* applying of write sets, in the receiving end

The applying happens by high priority transaction(s). Innodb lock manager has been modified to give preference to dedicated high priority MySQL threads.

There are also calls for providing "total order isolated" processing of certain SQL statements. This feature guarantees that each MySQL server in the cluster process the SQL statement in the same order and uninterrupted. .e.g. all DDL statements need to be processed isolated, to maintain data consistency in the cluster.

What is new in this release:

• better configuration system
• scriptable state transfer methods
• scriptable notifications for cluster and node state changes
• better status reporting for troubleshooting
• better performance through optimized flow control and parallel applying
• higher transparency (many compatibility bugs fixed)

What is new in version 0.8 Pre:

• This is a preview release of the upcoming 0.8 series which is delayed due to writeset format refactoring. It is fully representative of features and performance of the upcoming 0.8 and should be used for evaluations. 0.8 series is a result of 1.5 years of refactoring based on our experience with 0.7 and represents a well overhauled Galera, with respect to both performance and features.

What is new in version 0.7.4:

• 0.7.4 is a maintenance release and was published today. Release is available as usual as binary distribution for 32 and 64 bit linux platforms and as debian and RPM package distributions as well.

What is new in version 0.7.2:

• This release is a maintenance release. Release is available as binary distribution for 32 and 64 bit linux platforms in the downloads section.

What is new in version 0.7.1:

• 0.7.1 is a maintenance release and was published today. Release is available as binary distribution for 32 and 64 bit linux platforms in the downloads section

What is new in version 0.7:

• This relase comes only with the new gcomm group communication system, vsbes has been dropped. gcomm runs as part of mysqld process, and does not need a separate process to be started. Read the README file for instructions how to configure gcomm.
• During Q/A testing, we found two known issues, which were not fixed for this release. They deal with DDL/DML concurrency under high load and intermittent problem to shutdown gracefully.
• These issues have been filed as bugs and targeted for 0.7.1 release.

What is new in version 0.6.1:

• This release fixes #382408