+ // FIXME : Tentatively create a snapshot every hundred thousand entries. To be tuned.
+ if (journal.size() > context.getConfigParams().getSnapshotBatchCount()) {
+ LOG.info("Initiating Snapshot Capture..");
+ long lastAppliedIndex = -1;
+ long lastAppliedTerm = -1;
+
+ ReplicatedLogEntry lastAppliedEntry = get(context.getLastApplied());
+ if (lastAppliedEntry != null) {
+ lastAppliedIndex = lastAppliedEntry.getIndex();
+ lastAppliedTerm = lastAppliedEntry.getTerm();
+ }
+
+ LOG.debug("Snapshot Capture logSize: {}", journal.size());
+ LOG.debug("Snapshot Capture lastApplied:{} ", context.getLastApplied());
+ LOG.debug("Snapshot Capture lastAppliedIndex:{}", lastAppliedIndex);
+ LOG.debug("Snapshot Capture lastAppliedTerm:{}", lastAppliedTerm);
+
+ // create a snapshot object from the state provided and save it
+ // when snapshot is saved async, SaveSnapshotSuccess is raised.
+ Snapshot sn = Snapshot.create(createSnapshot(),
+ getFrom(context.getLastApplied() + 1),
+ lastIndex(), lastTerm(), lastAppliedIndex,
+ lastAppliedTerm);
+ saveSnapshot(sn);
+
+ LOG.info("Persisting of snapshot done:{}", sn.getLogMessage());
+
+ //be greedy and remove entries from in-mem journal which are in the snapshot
+ // and update snapshotIndex and snapshotTerm without waiting for the success,
+ // TODO: damage-recovery to be done on failure
+ journal.subList(0, (int) (lastAppliedIndex - snapshotIndex)).clear();
+ snapshotIndex = lastAppliedIndex;
+ snapshotTerm = lastAppliedTerm;
+
+ LOG.info("Removed in-memory snapshotted entries, " +
+ "adjusted snaphsotIndex:{}" +
+ "and term:{}", snapshotIndex, lastAppliedTerm);
+ }