Developing Apama Applications > Developing Apama Applications in EPL > Using Correlator Persistence > How the correlator recovers state > Simplest recovery use case
Simplest recovery use case
When you observe the following restrictions the correlator’s recovery behavior is straightforward:
*All monitors are persistent. The correlator contains no Java and no chunks.
*There are no implementations of onBeginRecovery() or onConcludeRecovery() actions.
EPL code that adheres to these restrictions appears to behave as if it is running in a completely reliable and fault tolerant system. The downside is that while the correlator is down, incoming or outgoing events are dropped. If you implement a "retransmit until acknowledge" protocol then the correlator can have a large number of events (and retransmits) to process when it restarts, depending on how long it is down.
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