anchor.diff:  }
   ```
   
  -and the Sink side of the connection will respond by setting up a SourceReplicationHandler to be run on the other host.
  +The sink-side of the connection will respond by setting up a `SourceReplicationHandler` to be run on the other host.
   
   ```
   --- !!meta-data #binary
  
positive.code: }
  ```
  
  HeartbeatHandlers are set up on both the source and sink machines. Periodically ( set via the `heartbeatIntervalMs` field ) they send a heartbeat message to their corresponding remote host. If the heartbeatTimeoutMs has passed ( and no heartbeat message has been received), the HeartbeatHandler will close the socket connection and attempt to reconnect.
  
  == Source Replication Handler
  
  Chronicle Queues are repliated using the SourceReplicationHandler, which sends its messages to the SinkReplicationHandler. Both the SourceReplicationHandler and SinkReplicationHandler are SubHandlers
  
  However handshaking messages are send back from the SinkReplicationHandler to the SourceReplicationHandler, one such message is the acknowledgement message which the sinks sends the source. By inspecting the `idx: 0x451600000000` ( see message below ) this alows you to added code on your source machine to ensure that message was received by the remote machine and therefore replicated.
  
  ```
  --- !!meta-data #binary
  
negative.code: ns: 10849029994071
  ```
  
  The handers are as follows:
  
  [%autowidth]
  |===
  | from	|	to 	| msg sent
  | source  |sink   | `software.chronicle.enterprise.queue.replication.SinkReplicationHandler`
  | sink  |source   | `software.chronicle.enterprise.queue.replication.SourceReplicationHandler`
  |===
  
  When using Chronicle Service, additional sink and source handlers are used to ensure that input queues are replicated before output queues.
  
  [%autowidth]
  |===
  | from	|	to 	| msg sent
  | source	| sink	| `software.chronicle.services.replication.ServicesReplicatedQueue.ServiceSourceReplicationHandler`
  | sink 	| source	| `software.chronicle.services.replication.ServicesReplicatedQueue.ServiceSinkReplicationHandler`
  |===
  
  The source-side of the connection sends a `ServiceSinkReplicationHandler` to be run on the remote machine.
  
  
  ```
  