Chapter 18. Failover Deployments

Abstract

Red Hat JBoss Fuse provides failover capability using either a simple lock file system or a JDBC locking mechanism. In both cases, a container-level lock system allows bundles to be preloaded into the slave kernel instance in order to provide faster failover performance.

18.1. Using a Simple Lock File System

Overview

When you first start Red Hat JBoss Fuse a lock file is created at the root of the installation directory. You can set up a master/slave system whereby if the master instance fails, the lock is passed to a slave instance that resides on the same host machine.

Configuring a lock file system

To configure a lock file failover deployment, edit the etc/system.properties file on both the master and the slave installation to include the properties in Example 18.1, “Lock File Failover Configuration”.

Example 18.1. Lock File Failover Configuration

karaf.lock=true
karaf.lock.class=org.apache.karaf.main.SimpleFileLock
karaf.lock.dir=PathToLockFileDirectory
karaf.lock.delay=10000
  • karaf.lock—specifies whether the lock file is written.
  • karaf.lock.class—specifies the Java class implementing the lock. For a simple file lock it should always be org.apache.karaf.main.SimpleFileLock.
  • karaf.lock.dir—specifies the directory into which the lock file is written. This must be the same for both the master and the slave installation.
  • karaf.lock.delay—specifies, in milliseconds, the delay between attempts to reaquire the lock.