replication: For taking snapshots use commit_index, not last_applied #50
+15
−5
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Currently entries are applied synchronously by the FSM as soon as they get committed.
However, we want to also support disk-based FSMs that might need to apply entries asynchronously. Using commit_index instead of last_applied when taking snapshots means that the raft engine will be able to request a snapshot even if some entries are still being applied by the FSM. Consumer code will queue the snapshot request and process it when outstanding entries have been applied.