/**
* Multicasts a GET_DIGEST_REQ to all current members and waits for all responses (GET_DIGEST_RSP)
* or N ms.
*
* @return
*/
private Digest fetchDigestsFromAllMembersInSubPartition(List<Address> current_mbrs) {
if (current_mbrs == null) return null;
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.GET_DIGEST_REQ);
Message get_digest_req = new Message();
get_digest_req.setFlag(Message.OOB);
get_digest_req.putHeader(gms.getId(), hdr);
long max_wait_time = gms.merge_timeout > 0 ? gms.merge_timeout / 2 : 2000L;
digest_collector.reset(current_mbrs);
// add my own digest first
Digest digest = (Digest) gms.getDownProtocol().down(Event.GET_DIGEST_EVT);
digest_collector.add(gms.local_addr, digest);
gms.getDownProtocol().down(new Event(Event.MSG, get_digest_req));
digest_collector.waitForAllResponses(max_wait_time);
if (log.isDebugEnabled()) {
if (digest_collector.hasAllResponses())
log.debug(gms.local_addr + ": fetched all digests for " + current_mbrs);
else
log.debug(
gms.local_addr
+ ": fetched incomplete digests (after timeout of "
+ max_wait_time
+ ") ms for "
+ current_mbrs);
}
Map<Address, Digest> responses = new HashMap<Address, Digest>(digest_collector.getResults());
MutableDigest retval = new MutableDigest(responses.size());
for (Digest dig : responses.values()) {
if (dig != null) retval.add(dig);
}
return retval;
}
/**
* Merge all digests into one. For each sender, the new value is max(highest_delivered),
* max(highest_received). This method has a lock on merge_rsps
*/
private Digest consolidateDigests(List<MergeData> merge_rsps, int num_mbrs) {
MutableDigest retval = new MutableDigest(num_mbrs);
for (MergeData data : merge_rsps) {
Digest tmp_digest = data.getDigest();
if (tmp_digest == null) continue;
retval.merge(tmp_digest);
}
return retval.copy();
}
/**
* Merge all digests into one. For each sender, the new value is min(low_seqno),
* max(high_seqno), max(high_seqno_seen). This method has a lock on merge_rsps
*/
private Digest consolidateDigests(Vector<MergeData> merge_rsps, int num_mbrs) {
MutableDigest retval = new MutableDigest(num_mbrs);
for (MergeData data : merge_rsps) {
Digest tmp_digest = data.getDigest();
if (tmp_digest == null) {
if (log.isErrorEnabled()) log.error("tmp_digest == null; skipping");
continue;
}
retval.merge(tmp_digest);
}
return retval.copy();
}
/**
* Multicasts a GET_DIGEST_REQ to all current members and waits for all responses (GET_DIGEST_RSP)
* or N ms.
*
* @return
*/
private Digest fetchDigestsFromAllMembersInSubPartition(
List<Address> current_mbrs, MergeId merge_id) {
// Optimization: if we're the only member, we don't need to multicast the get-digest message
if (current_mbrs == null
|| current_mbrs.size() == 1 && current_mbrs.get(0).equals(gms.local_addr))
return (Digest) gms.getDownProtocol().down(new Event(Event.GET_DIGEST, gms.local_addr));
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.GET_DIGEST_REQ);
hdr.merge_id = merge_id;
Message get_digest_req =
new Message().setFlag(Message.Flag.OOB, Message.Flag.INTERNAL).putHeader(gms.getId(), hdr);
long max_wait_time =
gms.merge_timeout / 2; // gms.merge_timeout is guaranteed to be > 0, verified in init()
digest_collector.reset(current_mbrs);
gms.getDownProtocol().down(new Event(Event.MSG, get_digest_req));
// add my own digest first - the get_digest_req needs to be sent first *before* getting our own
// digest, so
// we have that message in our digest !
Digest digest =
(Digest) gms.getDownProtocol().down(new Event(Event.GET_DIGEST, gms.local_addr));
digest_collector.add(gms.local_addr, digest);
digest_collector.waitForAllResponses(max_wait_time);
if (log.isTraceEnabled()) {
if (digest_collector.hasAllResponses())
log.trace(gms.local_addr + ": fetched all digests for " + current_mbrs);
else
log.trace(
gms.local_addr
+ ": fetched incomplete digests (after timeout of "
+ max_wait_time
+ ") ms for "
+ current_mbrs);
}
Map<Address, Digest> responses = new HashMap<Address, Digest>(digest_collector.getResults());
MutableDigest retval = new MutableDigest(responses.size());
for (Digest dig : responses.values()) {
if (dig != null) retval.add(dig);
}
return retval;
}
public void handleMembershipChange(Collection<Request> requests) {
boolean joinAndStateTransferInitiated = false;
boolean useFlushIfPresent = gms.use_flush_if_present;
Collection<Address> new_mbrs = new LinkedHashSet<>(requests.size());
Collection<Address> suspected_mbrs = new LinkedHashSet<>(requests.size());
Collection<Address> leaving_mbrs = new LinkedHashSet<>(requests.size());
boolean self_leaving = false; // is the coord leaving
for (Request req : requests) {
switch (req.type) {
case Request.JOIN:
new_mbrs.add(req.mbr);
if (req.useFlushIfPresent) useFlushIfPresent = true;
break;
case Request.JOIN_WITH_STATE_TRANSFER:
new_mbrs.add(req.mbr);
joinAndStateTransferInitiated = true;
if (req.useFlushIfPresent) useFlushIfPresent = true;
break;
case Request.LEAVE:
if (req.suspected) suspected_mbrs.add(req.mbr);
else {
leaving_mbrs.add(req.mbr);
if (gms.local_addr != null && gms.local_addr.equals(req.mbr)) self_leaving = true;
}
break;
case Request.SUSPECT:
suspected_mbrs.add(req.mbr);
break;
}
}
new_mbrs.remove(gms.local_addr); // remove myself - cannot join myself (already joined)
if (gms.getViewId() == null) {
// we're probably not the coord anymore (we just left ourselves), let someone else do it
// (client will retry when it doesn't get a response)
log.debug(
"gms.view_id is null, I'm not the coordinator anymore (leaving=%b); "
+ "the new coordinator will handle the leave request",
self_leaving);
return;
}
List<Address> current_members = gms.members.getMembers();
leaving_mbrs.retainAll(
current_members); // remove all elements of leaving_mbrs which are not current members
if (suspected_mbrs.remove(gms.local_addr))
log.warn("I am the coord and I'm being suspected -- will probably leave shortly");
suspected_mbrs.retainAll(
current_members); // remove all elements of suspected_mbrs which are not current members
// for the members that have already joined, return the current digest and membership
for (Iterator<Address> it = new_mbrs.iterator(); it.hasNext(); ) {
Address mbr = it.next();
if (gms.members.contains(mbr)) { // already joined: return current digest and membership
log.trace(
"%s: %s already present; returning existing view %s", gms.local_addr, mbr, gms.view);
Tuple<View, Digest> tuple = gms.getViewAndDigest();
if (tuple != null) gms.sendJoinResponse(new JoinRsp(tuple.getVal1(), tuple.getVal2()), mbr);
else
log.warn(
"%s: did not find a digest matching view %s; dropping JOIN-RSP",
gms.local_addr, gms.view);
it
.remove(); // remove it anyway, even if we didn't find a digest matching the view
// (joiner will retry)
}
}
if (new_mbrs.isEmpty() && leaving_mbrs.isEmpty() && suspected_mbrs.isEmpty()) {
log.trace("%s: found no members to add or remove, will not create new view", gms.local_addr);
return;
}
View new_view = gms.getNextView(new_mbrs, leaving_mbrs, suspected_mbrs);
if (new_view.size() == 0
&& gms.local_addr != null
&& gms.local_addr.equals(new_view.getCreator())) {
if (self_leaving) gms.initState(); // in case connect() is called again
return;
}
log.trace(
"%s: joiners=%s, suspected=%s, leaving=%s, new view: %s",
gms.local_addr, new_mbrs, suspected_mbrs, leaving_mbrs, new_view);
JoinRsp join_rsp = null;
boolean hasJoiningMembers = !new_mbrs.isEmpty();
try {
boolean successfulFlush =
!useFlushIfPresent || !gms.flushProtocolInStack || gms.startFlush(new_view);
if (!successfulFlush && hasJoiningMembers) {
// Don't send a join response if the flush fails
// (http://jira.jboss.org/jira/browse/JGRP-759)
// The joiner should block until the previous FLUSH completed
sendLeaveResponses(leaving_mbrs); // we still have to send potential leave responses
// but let the joining client timeout and send another join request
return;
}
// we cannot garbage collect during joining a new member *if* we're the only member
// Example: {A}, B joins, after returning JoinRsp to B, A garbage collects messages higher
// than those
// in the digest returned to the client, so the client will *not* be able to ask for
// retransmission
// of those messages if he misses them
if (hasJoiningMembers) {
gms.getDownProtocol().down(new Event(Event.SUSPEND_STABLE, MAX_SUSPEND_TIMEOUT));
// create a new digest, which contains the new members, minus left members
MutableDigest join_digest =
new MutableDigest(new_view.getMembersRaw()).set(gms.getDigest());
for (Address member : new_mbrs)
join_digest.set(member, 0, 0); // ... and set the new members. their first seqno will be 1
// If the digest from NAKACK doesn't include all members of the view, we try once more; if
// it is still
// incomplete, we don't send a JoinRsp back to the joiner(s). This shouldn't be a problem as
// they will retry
if (join_digest.allSet() || join_digest.set(gms.getDigest()).allSet())
join_rsp = new JoinRsp(new_view, join_digest);
else
log.warn(
"%s: digest does not match view (missing seqnos for %s); dropping JOIN-RSP",
gms.local_addr, Arrays.toString(join_digest.getNonSetMembers()));
}
sendLeaveResponses(leaving_mbrs); // no-op if no leaving members
// we don't need to send the digest to existing members:
// https://issues.jboss.org/browse/JGRP-1317
gms.castViewChange(new_view, null, new_mbrs);
gms.sendJoinResponses(join_rsp, new_mbrs);
} finally {
if (hasJoiningMembers) gms.getDownProtocol().down(new Event(Event.RESUME_STABLE));
if (!joinAndStateTransferInitiated && useFlushIfPresent) gms.stopFlush();
if (self_leaving) gms.initState(); // in case connect() is called again
}
}