Examples with AppendRequest io.atomix.protocols.raft.protocol.AppendRequest used on opensource projects

Example 1 with AppendRequest

use of io.atomix.protocols.raft.protocol.AppendRequest in project atomix by atomix.

the class AbstractAppender method buildAppendEntriesRequest.

/**
 * Builds a populated AppendEntries request.
 */
@SuppressWarnings("unchecked")
protected AppendRequest buildAppendEntriesRequest(RaftMemberContext member, long lastIndex) {
    final RaftLogReader reader = member.getLogReader();
    final Indexed<RaftLogEntry> prevEntry = reader.getCurrentEntry();
    final DefaultRaftMember leader = raft.getLeader();
    AppendRequest.Builder builder = AppendRequest.builder().withTerm(raft.getTerm()).withLeader(leader != null ? leader.nodeId() : null).withPrevLogIndex(prevEntry != null ? prevEntry.index() : reader.getFirstIndex() - 1).withPrevLogTerm(prevEntry != null ? prevEntry.entry().term() : 0).withCommitIndex(raft.getCommitIndex());
    // Build a list of entries to send to the member.
    final List<RaftLogEntry> entries = new ArrayList<>();
    // Build a list of entries up to the MAX_BATCH_SIZE. Note that entries in the log may
    // be null if they've been compacted and the member to which we're sending entries is just
    // joining the cluster or is otherwise far behind. Null entries are simply skipped and not
    // counted towards the size of the batch.
    // If there exists an entry in the log with size >= MAX_BATCH_SIZE the logic ensures that
    // entry will be sent in a batch of size one
    int size = 0;
    // Iterate through the log until the last index or the end of the log is reached.
    while (reader.hasNext()) {
        // Otherwise, read the next entry and add it to the batch.
        Indexed<RaftLogEntry> entry = reader.next();
        entries.add(entry.entry());
        size += entry.size();
        if (entry.index() == lastIndex || size >= MAX_BATCH_SIZE) {
            break;
        }
    }
    // Add the entries to the request builder and build the request.
    return builder.withEntries(entries).build();
}