High availability refers to the capability of failing over messaging engines between servers. File stores can be used in highly available environments.
WebSphere Application Server Version 6.1 supports two styles of file system access to enable this:
This style of file system access uses high availability clustering and failover of shared disks to ensure that the file store's directories are accessible from the server that is currently running the messaging engine. The file store's directories are located on file systems in the shared disks, and high availability cluster scripts are used to mount the file systems on the node with the server that is running the messaging engine.
This style of file system access uses a network file system. The most popular protocols for accessing remote files are Common Internet File System (CIFS) and Network File System (NFS). It is recommended that you adopt Version 4 of NFS, which supports automated failover to ensure access locking. Access locking ensures the integrity of the log files, that is, only a single client process can access the log at a time.