Apama 10.15.5 | 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 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.