Integration Server 10.5 | Clustering Guide | Managing Server Clustering | How a Stateful Integration Server Cluster and a Terracotta Server Array Handle Failures | What Happens When Terracotta Servers in the Terracotta Server Array Are Disconnected? | How Do Integration Servers Respond when Terracotta Servers in the Terracotta Server Array Are Disconnected?
 
How Do Integration Servers Respond when Terracotta Servers in the Terracotta Server Array Are Disconnected?
If the network connection is interrupted between the active server and one or more of the standby servers in the Terracotta Server Array, the Integration Servers that were connected to the active server will continue to use the same active server. However, if a new Integration Server joins the cluster, it will attempt to join the first Terracotta Server defined in the Terracotta Server Array URLs list. With this behavior, it is possible that new Integration Servers joining the cluster will connect to a new active server. This situation can lead to data loss when the servers reconnect. Additionally, while both servers are split, the Integration Server cluster might behave unpredictably because the Integration Servers in the cluster would have access to different cached data.
To avoid this situation, Software AG recommends that you shut down the new active server until the connection between the Terracotta servers is restored.
To prevent these issues, make sure the network connection between active server and standby servers in the Terracotta Server Array is reliable. For more information about preventing a split brain scenario, see "Split Brain Scenario" in the Terracotta Server Arrays Architecture documentation on the Terracotta website.