Brief explanation of what the Swarm health processor does

The Swarm health processor is a process that runs on each Swarm node to check the status of streams. The health processor performs the following actions:

• Sends replica checks to the other nodes and based on that adds or trims replicas
• Deletes streams that require deletion according to lifepoints
• Provides a safety net to remove older alias and named stream versions when a newer version is found in the cluster (can happen due to node restores or dropped multicasts)
• Checks each stream for data corruption by comparison with the stored stream hash
• Moves the stream on disk if defragmentation is necessary
• Insures the disk index is consistent with the streams found on disk
• Ensures proper subcluster distribution of replicas