The Content Platform Engine (CPE) is not yet aware that replicas are back online.
Symptoms
After all replicas in an advanced storage area go offline, users still cannot retrieve content when one or more replicas are brought back online.
Causes
This is a timing issue, having to do with how often the CPE server tests the connection status of replicas.
The CPE is set to test for restored connections to offline replicas at a specified time interval. If replica connectivity is restored after the CPE last checks the connections, then the CPE is unaware of the restored connections until its next connection check.
Resolving the problem
The CPE interval for testing replica connections is set on a JVM parameter, Advanced.ConnectivityRefreshSeconds. The default setting is 300 seconds, so the CPE tests connectivity of all of the replicas every five minutes. To have the CPE test connectivity at a more frequent rate, reduce the setting, for example, to 60 seconds.