Introduction to Master / Slave
The following are the different kinds of Master/Slave configurations available:
|Master Slave Type||Requirements||Pros||Cons|
|Shared File System Master Slave||A shared file system such as a SAN||Run as many slaves as required. Automatic recovery of old masters||Requires shared file system|
|JDBC Master Slave||A Shared database||Run as many slaves as required. Automatic recovery of old masters||Requires a shared database. Also relatively slow as it cannot use the high performance journal|
|Replicated LevelDB Store||ZooKeeper Server||Run as many slaves as required. Automatic recovery of old masters. Very fast.||Requires a ZooKeeper server.|
If you are using a shared network file system such as a SAN we recommend a Shared File System Master Slave. If you are happy to dispense with the high performance journal and are using pure JDBC as your persistence engine then you should use JDBC Master Slave instead. For those willing to try out new tech, the Replicated LevelDB Store gives speeds similar to a SAN solution without the hassle of having to setup a highly available shared file system.