static Message createMessage(Address dest, Address src) {
Message msg = new Message(dest, src, "hello world");
msg.putHeader(NAKACK_ID, NakAckHeader.createMessageHeader(322649));
msg.putHeader(UNICAST_ID, UNICAST.UnicastHeader.createDataHeader(465784, (short) 23323, true));
msg.putHeader(UDP_ID, new TpHeader("DrawDemo"));
return msg;
}
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);
}
}
});
}
}
}
}
}
private void sendViewAck(Address dest) {
Message view_ack = new Message(dest, null, null);
view_ack.setFlag(Message.OOB);
GmsHeader tmphdr = new GmsHeader(GmsHeader.VIEW_ACK);
view_ack.putHeader(this.id, tmphdr);
down_prot.down(new Event(Event.MSG, view_ack));
}
/**
* 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;
}
/**
* Sends the new view and digest to all subgroup coordinors in coords. Each coord will in turn
*
* <ol>
* <li>broadcast the new view and digest to all the members of its subgroup (MergeView)
* <li>on reception of the view, if it is a MergeView, each member will set the digest and
* install the new view
* </ol>
*/
private void sendMergeView(
Collection<Address> coords, MergeData combined_merge_data, MergeId merge_id) {
if (coords == null || combined_merge_data == null) return;
View view = combined_merge_data.view;
Digest digest = combined_merge_data.digest;
if (view == null || digest == null) {
if (log.isErrorEnabled())
log.error("view or digest is null, cannot send consolidated merge view/digest");
return;
}
if (log.isDebugEnabled())
log.debug(
gms.local_addr + ": sending merge view " + view.getVid() + " to coordinators " + coords);
gms.merge_ack_collector.reset(coords);
int size = gms.merge_ack_collector.size();
long timeout = gms.view_ack_collection_timeout;
long start = System.currentTimeMillis();
for (Address coord : coords) {
Message msg = new Message(coord, null, null);
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.INSTALL_MERGE_VIEW);
hdr.view = view;
hdr.my_digest = digest;
hdr.merge_id = merge_id;
msg.putHeader(gms.getId(), hdr);
gms.getDownProtocol().down(new Event(Event.MSG, msg));
}
// [JGRP-700] - FLUSH: flushing should span merge
// if flush is in stack wait for acks from separated island coordinators
if (gms.flushProtocolInStack) {
try {
gms.merge_ack_collector.waitForAllAcks(timeout);
long stop = System.currentTimeMillis();
if (log.isTraceEnabled())
log.trace(
"received all ACKs ("
+ size
+ ") for merge view "
+ view
+ " in "
+ (stop - start)
+ "ms");
} catch (TimeoutException e) {
log.warn(
gms.local_addr
+ ": failed to collect all ACKs for merge ("
+ size
+ ") for view "
+ view
+ " after "
+ timeout
+ "ms, missing ACKs from "
+ gms.merge_ack_collector.printMissing());
}
}
}
/**
* We need to resend our first message with our conn_id
*
* @param sender
* @param seqno Resend the non null messages in the range [lowest .. seqno]
*/
protected void handleResendingOfFirstMessage(Address sender, long seqno) {
if (log.isTraceEnabled())
log.trace(local_addr + " <-- SEND_FIRST_SEQNO(" + sender + "," + seqno + ")");
SenderEntry entry = send_table.get(sender);
Table<Message> win = entry != null ? entry.sent_msgs : null;
if (win == null) {
if (log.isErrorEnabled())
log.error(local_addr + ": sender window for " + sender + " not found");
return;
}
boolean first_sent = false;
for (long i = win.getLow() + 1; i <= seqno; i++) {
Message rsp = win.get(i);
if (rsp == null) continue;
if (first_sent) {
down_prot.down(new Event(Event.MSG, rsp));
} else {
first_sent = true;
// We need to copy the UnicastHeader and put it back into the message because Message.copy()
// doesn't copy
// the headers and therefore we'd modify the original message in the sender retransmission
// window
// (https://jira.jboss.org/jira/browse/JGRP-965)
Message copy = rsp.copy();
Unicast2Header hdr = (Unicast2Header) copy.getHeader(this.id);
Unicast2Header newhdr = hdr.copy();
newhdr.first = true;
copy.putHeader(this.id, newhdr);
down_prot.down(new Event(Event.MSG, copy));
}
}
}
protected void sendMergeRejectionMessage(Address dest) {
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.MERGE_RSP).setMergeRejected(true);
Message msg = new Message(dest).setFlag(Message.Flag.OOB).putHeader(GMS_ID, hdr);
if (this.authenticate_coord) msg.putHeader(this.id, new AuthHeader(this.auth_token));
log.debug("merge response=%s", hdr);
down_prot.down(msg);
}
protected void sendStableMessage(Address dest, short conn_id, long low, long high) {
Message stable_msg = new Message(dest, null, null);
Unicast2Header hdr = Unicast2Header.createStableHeader(conn_id, low, high);
stable_msg.putHeader(this.id, hdr);
stable_msg.setFlag(Message.OOB);
if (log.isTraceEnabled()) {
StringBuilder sb = new StringBuilder();
sb.append(local_addr)
.append(" --> STABLE(")
.append(dest)
.append(": ")
.append(low)
.append("-")
.append(high)
.append(", conn_id=")
.append(conn_id)
.append(")");
log.trace(sb.toString());
}
down_prot.down(new Event(Event.MSG, stable_msg));
ReceiverEntry entry = recv_table.get(dest);
NakReceiverWindow win = entry != null ? entry.received_msgs : null;
if (win != null) win.stable(win.getHighestDelivered());
}
public void retransmit(long first_seqno, long last_seqno, Address sender) {
if (last_seqno < first_seqno) return;
Unicast2Header hdr = Unicast2Header.createXmitReqHeader(first_seqno, last_seqno);
Message xmit_req = new Message(sender, null, null);
xmit_req.putHeader(this.id, hdr);
down_prot.down(new Event(Event.MSG, xmit_req));
}
/**
* Send all fragments as separate messages (with same ID !). Example:
*
* <pre>
* Given the generated ID is 2344, number of fragments=3, message {dst,src,buf}
* would be fragmented into:
*
* [2344,3,0]{dst,src,buf1},
* [2344,3,1]{dst,src,buf2} and
* [2344,3,2]{dst,src,buf3}
* </pre>
*/
private void fragment(Message msg) {
try {
byte[] buffer = msg.getRawBuffer();
List<Range> fragments = Util.computeFragOffsets(msg.getOffset(), msg.getLength(), frag_size);
int num_frags = fragments.size();
num_sent_frags.addAndGet(num_frags);
if (log.isTraceEnabled()) {
Address dest = msg.getDest();
StringBuilder sb = new StringBuilder("fragmenting packet to ");
sb.append((dest != null ? dest.toString() : "<all members>"))
.append(" (size=")
.append(buffer.length);
sb.append(") into ")
.append(num_frags)
.append(" fragment(s) [frag_size=")
.append(frag_size)
.append(']');
log.trace(sb.toString());
}
long frag_id = getNextId(); // used as a seqno
for (int i = 0; i < fragments.size(); i++) {
Range r = fragments.get(i);
// don't copy the buffer, only src, dest and headers. Only copy the headers one time !
Message frag_msg = msg.copy(false, i == 0);
frag_msg.setBuffer(buffer, (int) r.low, (int) r.high);
FragHeader hdr = new FragHeader(frag_id, i, num_frags);
frag_msg.putHeader(this.id, hdr);
down_prot.down(new Event(Event.MSG, frag_msg));
}
} catch (Exception e) {
if (log.isErrorEnabled()) log.error("fragmentation failure", e);
}
}
public void up(MessageBatch batch) {
for (Message msg : batch) {
DaisyHeader hdr = (DaisyHeader) msg.getHeader(getId());
if (hdr != null) {
// 1. forward the message to the next in line if ttl > 0
short ttl = hdr.getTTL();
if (log.isTraceEnabled())
log.trace(local_addr + ": received message from " + msg.getSrc() + " with ttl=" + ttl);
if (--ttl > 0) {
Message copy = msg.copy(true);
copy.setDest(next);
copy.putHeader(getId(), new DaisyHeader(ttl));
msgs_forwarded++;
if (log.isTraceEnabled())
log.trace(local_addr + ": forwarding message to " + next + " with ttl=" + ttl);
down_prot.down(new Event(Event.MSG, copy));
}
// 2. Pass up
msg.setDest(null);
}
}
if (!batch.isEmpty()) up_prot.up(batch);
}
/**
* Sends a MERGE_REQ to all coords and populates a list of MergeData (in merge_rsps). Returns
* after coords.size() response have been received, or timeout msecs have elapsed (whichever is
* first).
*
* <p>If a subgroup coordinator rejects the MERGE_REQ (e.g. because of participation in a
* different merge), <em>that member will be removed from coords !</em>
*
* @param coords A map of coordinatgor addresses and associated membership lists
* @param new_merge_id The new merge id
* @param timeout Max number of msecs to wait for the merge responses from the subgroup coords
*/
private boolean getMergeDataFromSubgroupCoordinators(
Map<Address, Collection<Address>> coords, MergeId new_merge_id, long timeout) {
boolean gotAllResponses;
long start = System.currentTimeMillis();
merge_rsps.reset(coords.keySet());
if (log.isDebugEnabled())
log.debug(gms.local_addr + ": sending MERGE_REQ to " + coords.keySet());
for (Map.Entry<Address, Collection<Address>> entry : coords.entrySet()) {
Address coord = entry.getKey();
Collection<Address> mbrs = entry.getValue();
Message msg = new Message(coord, null, null);
msg.setFlag(Message.OOB);
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.MERGE_REQ, mbrs);
hdr.mbr = gms.local_addr;
hdr.merge_id = new_merge_id;
msg.putHeader(gms.getId(), hdr);
gms.getDownProtocol().down(new Event(Event.MSG, msg));
}
// wait until num_rsps_expected >= num_rsps or timeout elapsed
merge_rsps.waitForAllResponses(timeout);
gotAllResponses = merge_rsps.hasAllResponses();
long stop = System.currentTimeMillis();
if (log.isDebugEnabled())
log.debug(
gms.local_addr
+ ": collected "
+ merge_rsps.size()
+ " merge response(s) in "
+ (stop - start)
+ " ms");
return gotAllResponses;
}
/**
* If merge_id is not equal to this.merge_id then discard. Else cast the view/digest to all
* members of this group.
*/
public void handleMergeView(final MergeData data, final MergeId merge_id) {
if (!matchMergeId(merge_id)) {
if (log.isErrorEnabled())
log.error("merge_ids don't match (or are null); merge view discarded");
return;
}
// only send to our *current* members, if we have A and B being merged (we are B), then we would
// *not*
// receive a VIEW_ACK from A because A doesn't see us in the pre-merge view yet and discards the
// view
// [JGRP-700] - FLUSH: flushing should span merge
// we have to send new view only to current members and we should not wait
// for view acks from newly merged mebers
List<Address> newViewMembers = new Vector<Address>(data.view.getMembers());
newViewMembers.removeAll(gms.members.getMembers());
gms.castViewChangeWithDest(data.view, data.digest, null, newViewMembers);
// if we have flush in stack send ack back to merge coordinator
if (gms.flushProtocolInStack) {
Message ack = new Message(data.getSender(), null, null);
ack.setFlag(Message.OOB);
GMS.GmsHeader ack_hdr = new GMS.GmsHeader(GMS.GmsHeader.INSTALL_MERGE_VIEW_OK);
ack.putHeader(gms.getId(), ack_hdr);
gms.getDownProtocol().down(new Event(Event.MSG, ack));
}
cancelMerge(merge_id);
}
public void sendGetMembersRequest(String cluster_name, Promise promise, boolean return_views_only)
throws Exception {
PhysicalAddress physical_addr =
(PhysicalAddress) down_prot.down(new Event(Event.GET_PHYSICAL_ADDRESS, local_addr));
PingData data =
new PingData(local_addr, null, false, UUID.get(local_addr), Arrays.asList(physical_addr));
PingHeader hdr = new PingHeader(PingHeader.GET_MBRS_REQ, data, cluster_name);
hdr.return_view_only = return_views_only;
Set<PhysicalAddress> combined_target_members = new HashSet<PhysicalAddress>(initial_hosts);
combined_target_members.addAll(dynamic_hosts);
for (final Address addr : combined_target_members) {
if (addr.equals(physical_addr)) 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 PING request to " + msg.getDest());
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 Object up(Event evt) {
switch (evt.getType()) {
case Event.MSG:
Message msg = (Message) evt.getArg();
DaisyHeader hdr = (DaisyHeader) msg.getHeader(getId());
if (hdr == null) break;
// 1. forward the message to the next in line if ttl > 0
short ttl = hdr.getTTL();
if (log.isTraceEnabled())
log.trace(local_addr + ": received message from " + msg.getSrc() + " with ttl=" + ttl);
if (--ttl > 0) {
Message copy = msg.copy(true);
copy.setDest(next);
copy.putHeader(getId(), new DaisyHeader(ttl));
msgs_forwarded++;
if (log.isTraceEnabled())
log.trace(local_addr + ": forwarding message to " + next + " with ttl=" + ttl);
down_prot.down(new Event(Event.MSG, copy));
}
// 2. Pass up
msg.setDest(null);
break;
}
return up_prot.up(evt);
}
protected void sendMergeRejectedResponse(Address sender, MergeId merge_id) {
Message msg = new Message(sender).setFlag(Message.Flag.OOB, Message.Flag.INTERNAL);
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.MERGE_RSP);
hdr.merge_rejected = true;
hdr.merge_id = merge_id;
msg.putHeader(gms.getId(), hdr);
gms.getDownProtocol().down(new Event(Event.MSG, msg));
}
public Object down(Message msg) {
GMS.GmsHeader hdr = getGMSHeader(msg);
if (hdr != null && needsAuthentication(hdr)) {
// we found a join request message - now add an AUTH Header
msg.putHeader(this.id, new AuthHeader(this.auth_token));
}
return down_prot.down(msg);
}
protected void sendMergeRejectionMessage(Address dest) {
Message msg = new Message(dest).setFlag(Message.Flag.OOB);
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.MERGE_RSP);
hdr.setMergeRejected(true);
msg.putHeader(gms_id, hdr);
if (log.isDebugEnabled()) log.debug("merge response=" + hdr);
down_prot.down(new Event(Event.MSG, msg));
}
/**
* Fetches the digests from all members and installs them again. Used only for diagnosis and
* support; don't use this otherwise !
*/
void fixDigests() {
Digest digest = fetchDigestsFromAllMembersInSubPartition(gms.view.getMembers());
Message msg = new Message();
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.INSTALL_DIGEST);
hdr.my_digest = digest;
msg.putHeader(gms.getId(), hdr);
gms.getDownProtocol().down(new Event(Event.MSG, msg));
}
protected void sendRequestForFirstSeqno(Address dest, long seqno_received) {
Message msg = new Message(dest).setFlag(Message.Flag.OOB, Message.Flag.INTERNAL);
UnicastHeader hdr = UnicastHeader.createSendFirstSeqnoHeader(seqno_received);
msg.putHeader(this.id, hdr);
if (log.isTraceEnabled())
log.trace(local_addr + " --> SEND_FIRST_SEQNO(" + dest + "," + seqno_received + ")");
down_prot.down(new Event(Event.MSG, msg));
}
/**
* Copies a message. Copies only headers with IDs >= starting_id or IDs which are in the
* copy_only_ids list
*
* @param copy_buffer
* @param starting_id
* @param copy_only_ids
* @return
*/
public Message copy(boolean copy_buffer, short starting_id, short... copy_only_ids) {
Message retval = copy(copy_buffer, false);
for (Map.Entry<Short, Header> entry : getHeaders().entrySet()) {
short id = entry.getKey();
if (id >= starting_id || containsId(id, copy_only_ids))
retval.putHeader(id, entry.getValue());
}
return retval;
}
/** Send back a response containing view and digest to sender */
private void sendMergeResponse(Address sender, View view, Digest digest, MergeId merge_id) {
Message msg = new Message(sender).setFlag(Message.Flag.OOB, Message.Flag.INTERNAL);
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.MERGE_RSP);
hdr.merge_id = merge_id;
hdr.view = view;
hdr.my_digest = digest;
msg.putHeader(gms.getId(), hdr);
if (log.isTraceEnabled()) log.trace(gms.local_addr + ": sending merge response=" + hdr);
gms.getDownProtocol().down(new Event(Event.MSG, msg));
}
public void retransmit(SeqnoList missing, Address sender) {
Unicast2Header hdr = Unicast2Header.createXmitReqHeader();
Message retransmit_msg = new Message(sender, null, missing);
retransmit_msg.setFlag(Message.OOB);
if (log.isTraceEnabled())
log.trace(local_addr + ": sending XMIT_REQ (" + missing + ") to " + sender);
retransmit_msg.putHeader(this.id, hdr);
down_prot.down(new Event(Event.MSG, retransmit_msg));
xmit_reqs_sent.addAndGet(missing.size());
}
protected void sendMergeRejectedResponse(Address sender, MergeId merge_id) {
Message msg = new Message(sender, null, null);
msg.setFlag(Message.OOB);
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.MERGE_RSP);
hdr.merge_rejected = true;
hdr.merge_id = merge_id;
msg.putHeader(gms.getId(), hdr);
if (log.isDebugEnabled()) log.debug("merge response=" + hdr);
gms.getDownProtocol().down(new Event(Event.MSG, msg));
}
/**
* Doesn't copy any headers except for those with ID >= copy_headers_above
*
* @param copy_buffer
* @param starting_id
* @return A message with headers whose ID are >= starting_id
*/
public Message copy(boolean copy_buffer, short starting_id) {
Message retval = copy(copy_buffer, false);
if (starting_id > 0) {
for (Map.Entry<Short, Header> entry : getHeaders().entrySet()) {
short id = entry.getKey();
if (id >= starting_id) retval.putHeader(id, entry.getValue());
}
}
return retval;
}
protected void sendJoinRejectionMessage(Address dest, String error_msg) {
if (dest == null) return;
JoinRsp joinRes = new JoinRsp(error_msg); // specify the error message on the JoinRsp
Message msg =
new Message(dest)
.putHeader(GMS_ID, new GMS.GmsHeader(GMS.GmsHeader.JOIN_RSP))
.setBuffer(GMS.marshal(joinRes));
if (this.authenticate_coord) msg.putHeader(this.id, new AuthHeader(this.auth_token));
down_prot.down(msg);
}
private void sendMergeCancelledMessage(Collection<Address> coords, MergeId merge_id) {
if (coords == null || merge_id == null) return;
for (Address coord : coords) {
Message msg = new Message(coord);
// msg.setFlag(Message.Flag.OOB);
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.CANCEL_MERGE);
hdr.merge_id = merge_id;
msg.putHeader(gms.getId(), hdr);
gms.getDownProtocol().down(new Event(Event.MSG, msg));
}
}
@Override
public Message nextMessage(Address address, SaslHeader header) throws SaslException {
Message message = new Message(address).setFlag(Message.Flag.OOB);
byte[] challenge = server.evaluateResponse(header.getPayload());
if (server.isComplete()) {
latch.countDown();
}
if (challenge != null) {
return message.putHeader(SASL.SASL_ID, new SaslHeader(Type.RESPONSE, challenge));
} else {
return null;
}
}
/**
* An event is to be sent down the stack. The layer may want to examine its type and perform some
* action on it, depending on the event's type. If the event is a message MSG, then the layer may
* need to add a header to it (or do nothing at all) before sending it down the stack using <code>
* down_prot.down()</code>. In case of a GET_ADDRESS event (which tries to retrieve the stack's
* address from one of the bottom layers), the layer may need to send a new response event back up
* the stack using <code>up_prot.up()</code>.
*/
public Object down(Event evt) {
GMS.GmsHeader hdr = getGMSHeader(evt);
if (hdr != null && needsAuthentication(hdr)) {
// we found a join request message - now add an AUTH Header
Message msg = (Message) evt.getArg();
AuthHeader authHeader = new AuthHeader(this.auth_token);
msg.putHeader(this.id, authHeader);
}
if (evt.getType() == Event.SET_LOCAL_ADDRESS) local_addr = (Address) evt.getArg();
return down_prot.down(evt);
}
private void sendMergeCancelledMessage(Collection<Address> coords, MergeId merge_id) {
if (coords == null || merge_id == null) return;
for (Address coord : coords) {
Message msg = new Message(coord, null, null);
// msg.setFlag(Message.OOB);
GMS.GmsHeader hdr = new GMS.GmsHeader(GMS.GmsHeader.CANCEL_MERGE);
hdr.merge_id = merge_id;
msg.putHeader(gms.getId(), hdr);
if (log.isDebugEnabled()) log.debug(gms.local_addr + ": sending cancel merge to " + coord);
gms.getDownProtocol().down(new Event(Event.MSG, msg));
}
}