use of com.hazelcast.cp.internal.raft.impl.RaftNodeStatus.STEPPED_DOWN in project hazelcast by hazelcast.
the class RaftNodeImpl method takeSnapshotIfCommitIndexAdvanced.
/**
* Takes a snapshot if the advance in {@code commitIndex} is equal to
* {@link RaftAlgorithmConfig#getCommitIndexAdvanceCountToSnapshot()}.
* <p>
* Snapshot is not created if the Raft group is being destroyed.
*/
@SuppressWarnings("checkstyle:npathcomplexity")
private void takeSnapshotIfCommitIndexAdvanced() {
long commitIndex = state.commitIndex();
if ((commitIndex - state.log().snapshotIndex()) < commitIndexAdvanceCountToSnapshot) {
return;
}
if (isTerminatedOrSteppedDown()) {
// If the status is TERMINATED or STEPPED_DOWN, then there will not be any new appends.
return;
}
RaftLog log = state.log();
Object snapshot = raftIntegration.takeSnapshot(commitIndex);
if (snapshot instanceof Throwable) {
Throwable t = (Throwable) snapshot;
logger.severe("Could not take snapshot at commit index: " + commitIndex, t);
return;
}
int snapshotTerm = log.getLogEntry(commitIndex).term();
RaftGroupMembers members = state.committedGroupMembers();
SnapshotEntry snapshotEntry = new SnapshotEntry(snapshotTerm, commitIndex, snapshot, members.index(), members.members());
long highestLogIndexToTruncate = commitIndex - maxNumberOfLogsToKeepAfterSnapshot;
LeaderState leaderState = state.leaderState();
if (leaderState != null) {
long[] matchIndices = leaderState.matchIndices();
// Last slot is reserved for leader index and always zero.
// If there is at least one follower with unknown match index,
// its log can be close to the leader's log so we are keeping the old log entries.
boolean allMatchIndicesKnown = Arrays.stream(matchIndices, 0, matchIndices.length - 1).noneMatch(i -> i == 0);
if (allMatchIndicesKnown) {
// Otherwise, we will keep the log entries until the minimum match index
// that is bigger than (commitIndex - maxNumberOfLogsToKeepAfterSnapshot).
// If there is no such follower (all of the minority followers are far behind),
// then there is no need to keep the old log entries.
highestLogIndexToTruncate = Arrays.stream(matchIndices).filter(i -> i < commitIndex).filter(i -> i > commitIndex - maxNumberOfLogsToKeepAfterSnapshot).map(i -> i - 1).sorted().findFirst().orElse(commitIndex);
}
}
int truncatedEntryCount = log.setSnapshot(snapshotEntry, highestLogIndexToTruncate);
if (logger.isFineEnabled()) {
logger.fine(snapshotEntry + " is taken, " + truncatedEntryCount + " entries are truncated.");
}
}
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