anchor.diff:  
   ----
   karaf.lock=true
  -karaf.lock.class=org.apache.karaf.main.DefaultJDBCLock
  +karaf.lock.class=org.apache.karaf.main.lock.DefaultJDBCLock
   karaf.lock.level=50
   karaf.lock.delay=10000
   karaf.lock.jdbc.url=jdbc:derby://dbserver:1527/sample
  
positive.code: 
  ----
  karaf.lock=true
  karaf.lock.class=org.apache.karaf.main.SimpleFileLock
  karaf.lock.dir=<PathToLockFileDirectory>
  karaf.lock.delay=10000
  ----
  
negative.code: ----
  
  * `karaf.lock` property enabled the HA/failover mechanism
  * `karaf.lock.class` property contains the class name providing the lock implementation. The `org.apache.karaf.main.lock.DefaultJDBCLock`
   is the most generic database lock system implementation. Apache Karaf supports lock system for specific databases (see later for details).
  * `karaf.lock.level` property is the container-level locking (see later for details).
  * `karaf.lock.delay` property is the interval period (in milliseconds) to check if the lock has been released or not.
  