Minor Description
kahadb/src/main/java/org/apache/kahadb/util/LockFile.java adds in-JVM locking to Channel.tryLock() using system properties. However, there is time between the read-and-check for an existing lock and setting a new lock.
I found this problem while running multiple brokers in a single JVM for diagnostic purposes with two brokers using a shared directory to simlute a production H/A environment.