private ElectionResult countVotes(
HashMap<InetSocketAddress, Vote> votes, HashSet<Long> heardFrom) {
ElectionResult result = new ElectionResult();
// Initialize with null vote
result.vote = new Vote(Long.MIN_VALUE, Long.MIN_VALUE);
result.winner = new Vote(Long.MIN_VALUE, Long.MIN_VALUE);
Collection<Vote> votesCast = votes.values();
// First make the views consistent. Sometimes peers will have
// different zxids for a server depending on timing.
for (Iterator<Vote> i = votesCast.iterator(); i.hasNext(); ) {
Vote v = i.next();
if (!heardFrom.contains(v.id)) {
// Discard votes for machines that we didn't hear from
i.remove();
continue;
}
for (Vote w : votesCast) {
if (v.id == w.id) {
if (v.zxid < w.zxid) {
v.zxid = w.zxid;
}
}
}
}
HashMap<Vote, Integer> countTable = new HashMap<Vote, Integer>();
// Now do the tally
for (Vote v : votesCast) {
Integer count = countTable.get(v);
if (count == null) {
count = Integer.valueOf(0);
}
countTable.put(v, count + 1);
if (v.id == result.vote.id) {
result.count++;
} else if (v.zxid > result.vote.zxid
|| (v.zxid == result.vote.zxid && v.id > result.vote.id)) {
result.vote = v;
result.count = 1;
}
}
result.winningCount = 0;
LOG.info("Election tally: ");
for (Entry<Vote, Integer> entry : countTable.entrySet()) {
if (entry.getValue() > result.winningCount) {
result.winningCount = entry.getValue();
result.winner = entry.getKey();
}
LOG.info(entry.getKey().id + "\t-> " + entry.getValue());
}
return result;
}
private void leaveInstance(Vote v) {
if (LOG.isDebugEnabled()) {
LOG.debug(
"About to leave FLE instance: leader="
+ v.getId()
+ ", zxid=0x"
+ Long.toHexString(v.getZxid())
+ ", my id="
+ self.getId()
+ ", my state="
+ self.getPeerState());
}
recvqueue.clear();
}
/**
* Termination predicate. Given a set of votes, determines if have sufficient to declare the end
* of the election round.
*
* @param votes Set of votes
* @param l Identifier of the vote received last
* @param zxid zxid of the the vote received last
*/
protected boolean termPredicate(HashMap<Long, Vote> votes, Vote vote) {
HashSet<Long> set = new HashSet<Long>();
/*
* First make the views consistent. Sometimes peers will have different
* zxids for a server depending on timing.
*/
for (Map.Entry<Long, Vote> entry : votes.entrySet()) {
if (vote.equals(entry.getValue())) {
set.add(entry.getKey());
}
}
return self.getQuorumVerifier().containsQuorum(set);
}
public void run() {
Message response;
while (!stop) {
// Sleeps on receive
try {
response = manager.pollRecvQueue(3000, TimeUnit.MILLISECONDS);
if (response == null) continue;
/*
* If it is from an observer, respond right away. Note
* that the following predicate assumes that if a server
* is not a follower, then it must be an observer. If we
* ever have any other type of learner in the future,
* we'll have to change the way we check for observers.
*/
if (!self.getVotingView().containsKey(response.sid)) {
Vote current = self.getCurrentVote();
ToSend notmsg =
new ToSend(
ToSend.mType.notification,
current.getId(),
current.getZxid(),
logicalclock,
self.getPeerState(),
response.sid,
current.getPeerEpoch());
sendqueue.offer(notmsg);
} else {
// Receive new message
if (LOG.isDebugEnabled()) {
LOG.debug("Receive new notification message. My id = " + self.getId());
}
/*
* We check for 28 bytes for backward compatibility
*/
if (response.buffer.capacity() < 28) {
LOG.error("Got a short response: " + response.buffer.capacity());
continue;
}
boolean backCompatibility = (response.buffer.capacity() == 28);
response.buffer.clear();
// Instantiate Notification and set its attributes
Notification n = new Notification();
// State of peer that sent this message
QuorumPeer.ServerState ackstate = QuorumPeer.ServerState.LOOKING;
switch (response.buffer.getInt()) {
case 0:
ackstate = QuorumPeer.ServerState.LOOKING;
break;
case 1:
ackstate = QuorumPeer.ServerState.FOLLOWING;
break;
case 2:
ackstate = QuorumPeer.ServerState.LEADING;
break;
case 3:
ackstate = QuorumPeer.ServerState.OBSERVING;
break;
default:
continue;
}
n.leader = response.buffer.getLong();
n.zxid = response.buffer.getLong();
n.electionEpoch = response.buffer.getLong();
n.state = ackstate;
n.sid = response.sid;
if (!backCompatibility) {
n.peerEpoch = response.buffer.getLong();
} else {
if (LOG.isInfoEnabled()) {
LOG.info("Backward compatibility mode, server id=" + n.sid);
}
n.peerEpoch = ZxidUtils.getEpochFromZxid(n.zxid);
}
/*
* Version added in 3.4.6
*/
n.version = (response.buffer.remaining() >= 4) ? response.buffer.getInt() : 0x0;
/*
* Print notification info
*/
if (LOG.isInfoEnabled()) {
printNotification(n);
}
/*
* If this server is looking, then send proposed
* leader
*/
if (self.getPeerState() == QuorumPeer.ServerState.LOOKING) {
recvqueue.offer(n);
/*
* Send a notification back if the peer that
* sent this message is also looking and its
* logical clock is lagging behind.
*/
if ((ackstate == QuorumPeer.ServerState.LOOKING)
&& (n.electionEpoch < logicalclock)) {
Vote v = getVote();
ToSend notmsg =
new ToSend(
ToSend.mType.notification,
v.getId(),
v.getZxid(),
logicalclock,
self.getPeerState(),
response.sid,
v.getPeerEpoch());
sendqueue.offer(notmsg);
}
} else {
/*
* If this server is not looking, but the one
* that sent the ack is looking, then send back
* what it believes to be the leader.
*/
Vote current = self.getCurrentVote();
if (ackstate == QuorumPeer.ServerState.LOOKING) {
if (LOG.isDebugEnabled()) {
LOG.debug(
"Sending new notification. My id = "
+ self.getId()
+ " recipient="
+ response.sid
+ " zxid=0x"
+ Long.toHexString(current.getZxid())
+ " leader="
+ current.getId());
}
ToSend notmsg;
if (n.version > 0x0) {
notmsg =
new ToSend(
ToSend.mType.notification,
current.getId(),
current.getZxid(),
current.getElectionEpoch(),
self.getPeerState(),
response.sid,
current.getPeerEpoch());
} else {
Vote bcVote = self.getBCVote();
notmsg =
new ToSend(
ToSend.mType.notification,
bcVote.getId(),
bcVote.getZxid(),
bcVote.getElectionEpoch(),
self.getPeerState(),
response.sid,
bcVote.getPeerEpoch());
}
sendqueue.offer(notmsg);
}
}
}
} catch (InterruptedException e) {
System.out.println(
"Interrupted Exception while waiting for new message" + e.toString());
}
}
LOG.info("WorkerReceiver is down");
}