protected void forwardToCoord(long seqno, Message msg) {
if (is_coord) {
forward(msg, seqno, false);
return;
}
if (!running || flushing) {
forward_table.put(seqno, msg);
return;
}
if (!ack_mode) {
forward_table.put(seqno, msg);
forward(msg, seqno, false);
return;
}
send_lock.lock();
try {
forward_table.put(seqno, msg);
while (running && !flushing) {
ack_promise.reset();
forward(msg, seqno, true);
if (!ack_mode || !running || flushing) break;
Long ack = ack_promise.getResult(500);
if ((Objects.equals(ack, seqno)) || !forward_table.containsKey(seqno)) break;
}
} finally {
send_lock.unlock();
}
}
public List<PingData> get(long timeout) throws InterruptedException {
long start_time = System.currentTimeMillis(), time_to_wait = timeout;
promise.getLock().lock();
try {
while (time_to_wait > 0 && !promise.hasResult()) {
// if num_expected_srv_rsps > 0, then it overrides num_expected_rsps
if (num_expected_srv_rsps > 0) {
int received_srv_rsps = getNumServerResponses(ping_rsps);
if (received_srv_rsps >= num_expected_srv_rsps)
return new LinkedList<PingData>(ping_rsps);
} else if (ping_rsps.size() >= num_expected_rsps) {
return new LinkedList<PingData>(ping_rsps);
}
if (break_on_coord_rsp && containsCoordinatorResponse(ping_rsps))
return new LinkedList<PingData>(ping_rsps);
promise.getCond().await(time_to_wait, TimeUnit.MILLISECONDS);
time_to_wait = timeout - (System.currentTimeMillis() - start_time);
}
return new LinkedList<PingData>(ping_rsps);
} finally {
promise.getLock().unlock();
}
}
protected void deliver(Message msg, Event evt, SequencerHeader hdr) {
Address sender = msg.getSrc();
if (sender == null) {
if (log.isErrorEnabled())
log.error(local_addr + ": sender is null, cannot deliver " + "::" + hdr.getSeqno());
return;
}
long msg_seqno = hdr.getSeqno();
if (sender.equals(local_addr)) {
forward_table.remove(msg_seqno);
if (hdr.flush_ack) {
ack_promise.setResult(msg_seqno);
if (ack_mode && !flushing && threshold > 0 && ++num_acks >= threshold) {
ack_mode = false;
num_acks = 0;
}
}
}
if (!canDeliver(sender, msg_seqno)) {
if (log.isWarnEnabled())
log.warn(local_addr + ": dropped duplicate message " + sender + "::" + msg_seqno);
return;
}
if (log.isTraceEnabled()) log.trace(local_addr + ": delivering " + sender + "::" + msg_seqno);
up_prot.up(evt);
delivered_bcasts++;
}
protected void unblockAll() {
flushing = false;
send_lock.lock();
try {
send_cond.signalAll();
ack_promise.setResult(null);
} finally {
send_lock.unlock();
}
}
protected void stopFlusher() {
flushing = false;
Thread tmp = flusher;
while (tmp != null && tmp.isAlive()) {
tmp.interrupt();
ack_promise.setResult(null);
try {
tmp.join();
} catch (InterruptedException e) {
}
}
}
public void sendDiscoveryRequest(String cluster_name, Promise promise, ViewId view_id)
throws Exception {
PingData data = null;
PhysicalAddress physical_addr =
(PhysicalAddress) down(new Event(Event.GET_PHYSICAL_ADDRESS, local_addr));
if (view_id == null) {
List<PhysicalAddress> physical_addrs = Arrays.asList(physical_addr);
data = new PingData(local_addr, null, false, UUID.get(local_addr), physical_addrs);
}
PingHeader hdr = new PingHeader(PingHeader.GET_MBRS_REQ, data, cluster_name);
hdr.view_id = view_id;
Collection<PhysicalAddress> cluster_members = fetchClusterMembers(cluster_name);
if (cluster_members == null) {
Message msg = new Message(null); // multicast msg
msg.setFlag(Message.OOB);
msg.putHeader(getId(), hdr);
sendMcastDiscoveryRequest(msg);
} else {
if (cluster_members.isEmpty()) { // if we don't find any members, return immediately
if (promise != null) promise.setResult(null);
} else {
for (final Address addr : cluster_members) {
if (addr.equals(physical_addr)) // no need to send the request to myself
continue;
final Message msg = new Message(addr, null, null);
msg.setFlag(Message.OOB);
msg.putHeader(this.id, hdr);
if (log.isTraceEnabled())
log.trace("[FIND_INITIAL_MBRS] sending discovery request to " + msg.getDest());
if (!sendDiscoveryRequestsInParallel()) {
down_prot.down(new Event(Event.MSG, msg));
} else {
timer.execute(
new Runnable() {
public void run() {
try {
down_prot.down(new Event(Event.MSG, msg));
} catch (Exception ex) {
if (log.isErrorEnabled())
log.error("failed sending discovery request to " + addr + ": " + ex);
}
}
});
}
}
}
}
}
public void addResponse(PingData rsp, boolean overwrite) {
if (rsp == null) return;
promise.getLock().lock();
try {
if (overwrite) ping_rsps.remove(rsp);
// https://jira.jboss.org/jira/browse/JGRP-1179
int index = ping_rsps.indexOf(rsp);
if (index == -1) {
ping_rsps.add(rsp);
promise.getCond().signalAll();
} else if (rsp.isCoord()) {
PingData pr = ping_rsps.get(index);
// Check if the already existing element is not server
if (!pr.isCoord()) {
ping_rsps.set(index, rsp);
promise.getCond().signalAll();
}
}
} finally {
promise.getLock().unlock();
}
}
/**
* Sends all messages currently in forward_table to the new coordinator (changing the dest field).
* This needs to be done, so the underlying reliable unicast protocol (e.g. UNICAST) adds these
* messages to its retransmission mechanism<br>
* Note that we need to resend the messages in order of their seqnos ! We also need to prevent
* other message from being inserted until we're done, that's why there's synchronization.<br>
* Access to the forward_table doesn't need to be synchronized as there won't be any insertions
* during flushing (all down-threads are blocked)
*/
protected void flushMessagesInForwardTable() {
if (is_coord) {
for (Map.Entry<Long, Message> entry : forward_table.entrySet()) {
Long key = entry.getKey();
Message msg = entry.getValue();
Buffer buf;
try {
buf = Util.streamableToBuffer(msg);
} catch (Exception e) {
log.error(Util.getMessage("FlushingBroadcastingFailed"), e);
continue;
}
SequencerHeader hdr = new SequencerHeader(SequencerHeader.WRAPPED_BCAST, key);
Message forward_msg = new Message(null, buf).putHeader(this.id, hdr);
if (log.isTraceEnabled())
log.trace(local_addr + ": flushing (broadcasting) " + local_addr + "::" + key);
down_prot.down(new Event(Event.MSG, forward_msg));
}
return;
}
// for forwarded messages, we need to receive the forwarded message from the coordinator, to
// prevent this case:
// - V1={A,B,C}
// - A crashes
// - C installs V2={B,C}
// - C forwards messages 3 and 4 to B (the new coord)
// - B drops 3 because its view is still V1
// - B installs V2
// - B receives message 4 and broadcasts it
// ==> C's message 4 is delivered *before* message 3 !
// ==> By resending 3 until it is received, then resending 4 until it is received, we make sure
// this won't happen
// (see https://issues.jboss.org/browse/JGRP-1449)
while (flushing && running && !forward_table.isEmpty()) {
Map.Entry<Long, Message> entry = forward_table.firstEntry();
final Long key = entry.getKey();
Message msg = entry.getValue();
Buffer buf;
try {
buf = Util.streamableToBuffer(msg);
} catch (Exception e) {
log.error(Util.getMessage("FlushingBroadcastingFailed"), e);
continue;
}
while (flushing && running && !forward_table.isEmpty()) {
SequencerHeader hdr = new SequencerHeader(SequencerHeader.FLUSH, key);
Message forward_msg =
new Message(coord, buf).putHeader(this.id, hdr).setFlag(Message.Flag.DONT_BUNDLE);
if (log.isTraceEnabled())
log.trace(
local_addr
+ ": flushing (forwarding) "
+ local_addr
+ "::"
+ key
+ " to coord "
+ coord);
ack_promise.reset();
down_prot.down(new Event(Event.MSG, forward_msg));
Long ack = ack_promise.getResult(500);
if ((Objects.equals(ack, key)) || !forward_table.containsKey(key)) break;
}
}
}