Examples with TermIndex org.apache.ratis.server.protocol.TermIndex used on opensource projects

Example 1 with TermIndex

use of org.apache.ratis.server.protocol.TermIndex in project incubator-ratis by apache.

the class LeaderElection method askForVotes.

/**
 * After a peer changes its role to candidate, it invokes this method to
 * send out requestVote rpc to all other peers.
 */
private void askForVotes() throws InterruptedException, IOException {
    final ServerState state = server.getState();
    while (running && server.isCandidate()) {
        // one round of requestVotes
        final long electionTerm;
        synchronized (server) {
            electionTerm = state.initElection();
            server.getState().persistMetadata();
        }
        LOG.info(state.getSelfId() + ": begin an election in Term " + electionTerm);
        TermIndex lastEntry = state.getLog().getLastEntryTermIndex();
        if (lastEntry == null) {
            // lastEntry may need to be derived from snapshot
            SnapshotInfo snapshot = state.getLatestSnapshot();
            if (snapshot != null) {
                lastEntry = snapshot.getTermIndex();
            }
        }
        final ResultAndTerm r;
        if (others.isEmpty()) {
            r = new ResultAndTerm(Result.PASSED, electionTerm);
        } else {
            try {
                initExecutor();
                int submitted = submitRequests(electionTerm, lastEntry);
                r = waitForResults(electionTerm, submitted);
            } finally {
                if (executor != null) {
                    executor.shutdown();
                }
            }
        }
        synchronized (server) {
            if (electionTerm != state.getCurrentTerm() || !running || !server.isCandidate()) {
                // term already passed or no longer a candidate.
                return;
            }
            switch(r.result) {
                case PASSED:
                    server.changeToLeader();
                    return;
                case SHUTDOWN:
                    LOG.info("{} received shutdown response when requesting votes.", server.getId());
                    server.getProxy().close();
                    return;
                case REJECTED:
                case DISCOVERED_A_NEW_TERM:
                    final long term = r.term > server.getState().getCurrentTerm() ? r.term : server.getState().getCurrentTerm();
                    server.changeToFollower(term, true);
                    return;
                case TIMEOUT:
            }
        }
    }
}

Example 2 with TermIndex

use of org.apache.ratis.server.protocol.TermIndex in project incubator-ratis by apache.

the class RaftServerImpl method installSnapshot.

@Override
public InstallSnapshotReplyProto installSnapshot(InstallSnapshotRequestProto request) throws IOException {
    final RaftRpcRequestProto r = request.getServerRequest();
    final RaftPeerId leaderId = RaftPeerId.valueOf(r.getRequestorId());
    final RaftGroupId leaderGroupId = ProtoUtils.toRaftGroupId(r.getRaftGroupId());
    CodeInjectionForTesting.execute(INSTALL_SNAPSHOT, getId(), leaderId, request);
    LOG.debug("{}: receive installSnapshot({})", getId(), request);
    assertLifeCycleState(STARTING, RUNNING);
    assertGroup(leaderId, leaderGroupId);
    final long currentTerm;
    final long leaderTerm = request.getLeaderTerm();
    final TermIndex lastTermIndex = ServerProtoUtils.toTermIndex(request.getTermIndex());
    final long lastIncludedIndex = lastTermIndex.getIndex();
    synchronized (this) {
        final boolean recognized = state.recognizeLeader(leaderId, leaderTerm);
        currentTerm = state.getCurrentTerm();
        if (!recognized) {
            final InstallSnapshotReplyProto reply = ServerProtoUtils.toInstallSnapshotReplyProto(leaderId, getId(), groupId, currentTerm, request.getRequestIndex(), InstallSnapshotResult.NOT_LEADER);
            LOG.debug("{}: do not recognize leader for installing snapshot." + " Reply: {}", getId(), reply);
            return reply;
        }
        changeToFollower(leaderTerm, true);
        state.setLeader(leaderId, "installSnapshot");
        if (lifeCycle.getCurrentState() == RUNNING) {
            heartbeatMonitor.updateLastRpcTime(true);
        }
        // Check and append the snapshot chunk. We simply put this in lock
        // considering a follower peer requiring a snapshot installation does not
        // have a lot of requests
        Preconditions.assertTrue(state.getLog().getNextIndex() <= lastIncludedIndex, "%s log's next id is %s, last included index in snapshot is %s", getId(), state.getLog().getNextIndex(), lastIncludedIndex);
        // TODO: We should only update State with installed snapshot once the request is done.
        state.installSnapshot(request);
        // re-load the state machine if this is the last chunk
        if (request.getDone()) {
            state.reloadStateMachine(lastIncludedIndex, leaderTerm);
        }
        if (lifeCycle.getCurrentState() == RUNNING) {
            heartbeatMonitor.updateLastRpcTime(false);
        }
    }
    if (request.getDone()) {
        LOG.info("{}: successfully install the whole snapshot-{}", getId(), lastIncludedIndex);
    }
    return ServerProtoUtils.toInstallSnapshotReplyProto(leaderId, getId(), groupId, currentTerm, request.getRequestIndex(), InstallSnapshotResult.SUCCESS);
}

Example 3 with TermIndex

use of org.apache.ratis.server.protocol.TermIndex in project incubator-ratis by apache.

the class ServerState method isLogUpToDate.

boolean isLogUpToDate(TermIndex candidateLastEntry) {
    TermIndex local = log.getLastEntryTermIndex();
    // need to take into account snapshot
    SnapshotInfo snapshot = server.getStateMachine().getLatestSnapshot();
    if (local == null && snapshot == null) {
        return true;
    } else if (candidateLastEntry == null) {
        return false;
    }
    if (local == null || (snapshot != null && snapshot.getIndex() > local.getIndex())) {
        local = snapshot.getTermIndex();
    }
    return local.compareTo(candidateLastEntry) <= 0;
}

Example 4 with TermIndex

use of org.apache.ratis.server.protocol.TermIndex in project incubator-ratis by apache.

the class MemoryRaftLog method getEntries.

@Override
public TermIndex[] getEntries(long startIndex, long endIndex) {
    checkLogState();
    try (AutoCloseableLock readLock = readLock()) {
        final int from = (int) startIndex;
        if (startIndex >= entries.size()) {
            return null;
        }
        final int to = (int) Math.min(entries.size(), endIndex);
        TermIndex[] ti = new TermIndex[to - from];
        for (int i = 0; i < ti.length; i++) {
            ti[i] = TermIndex.newTermIndex(entries.get(i).getTerm(), entries.get(i).getIndex());
        }
        return ti;
    }
}

Example 5 with TermIndex

use of org.apache.ratis.server.protocol.TermIndex in project incubator-ratis by apache.

the class RaftLog method updateLastCommitted.

/**
 * Update the last committed index.
 * @param majorityIndex the index that has achieved majority.
 * @param currentTerm the current term.
 * @return true if update is applied; otherwise, return false, i.e. no update required.
 */
public boolean updateLastCommitted(long majorityIndex, long currentTerm) {
    try (AutoCloseableLock writeLock = writeLock()) {
        if (lastCommitted.get() < majorityIndex) {
            // Only update last committed index for current term. See §5.4.2 in
            // paper for details.
            final TermIndex entry = getTermIndex(majorityIndex);
            if (entry != null && entry.getTerm() == currentTerm) {
                LOG.debug("{}: Updating lastCommitted to {}", selfId, majorityIndex);
                lastCommitted.set(majorityIndex);
                return true;
            }
        }
    }
    return false;
}