/**
* 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>
* PassDown</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>. The PING protocol is interested in several different
* down events, Event.FIND_INITIAL_MBRS - sent by the GMS layer and expecting a GET_MBRS_OK
* Event.TMP_VIEW and Event.VIEW_CHANGE - a view change event Event.BECOME_SERVER - called after
* client has joined and is fully working group member Event.CONNECT, Event.DISCONNECT.
*/
@SuppressWarnings("unchecked")
public Object down(Event evt) {
switch (evt.getType()) {
case Event.FIND_INITIAL_MBRS: // sent by GMS layer
case Event.FIND_ALL_VIEWS:
// sends the GET_MBRS_REQ to all members, waits 'timeout' ms or until 'num_initial_members'
// have been retrieved
long start = System.currentTimeMillis();
boolean find_all_views = evt.getType() == Event.FIND_ALL_VIEWS;
Promise<JoinRsp> promise = (Promise<JoinRsp>) evt.getArg();
List<PingData> rsps = find_all_views ? findAllViews(promise) : findInitialMembers(promise);
long diff = System.currentTimeMillis() - start;
if (log.isTraceEnabled())
log.trace("discovery took " + diff + " ms: responses: " + Util.printPingData(rsps));
return rsps;
case Event.TMP_VIEW:
case Event.VIEW_CHANGE:
List<Address> tmp;
view = (View) evt.getArg();
if ((tmp = view.getMembers()) != null) {
synchronized (members) {
members.clear();
members.addAll(tmp);
}
}
current_coord = !members.isEmpty() ? members.get(0) : null;
is_coord = current_coord != null && local_addr != null && current_coord.equals(local_addr);
return down_prot.down(evt);
case Event.BECOME_SERVER: // called after client has joined and is fully working group member
down_prot.down(evt);
is_server = true;
return null;
case Event.SET_LOCAL_ADDRESS:
local_addr = (Address) evt.getArg();
return down_prot.down(evt);
case Event.CONNECT:
case Event.CONNECT_WITH_STATE_TRANSFER:
case Event.CONNECT_USE_FLUSH:
case Event.CONNECT_WITH_STATE_TRANSFER_USE_FLUSH:
is_leaving = false;
group_addr = (String) evt.getArg();
Object ret = down_prot.down(evt);
handleConnect();
return ret;
case Event.DISCONNECT:
is_leaving = true;
handleDisconnect();
return down_prot.down(evt);
default:
return down_prot.down(evt); // Pass on to the layer below us
}
}
protected Address generateAddress() {
if (address_generators == null || address_generators.isEmpty()) return UUID.randomUUID();
if (address_generators.size() == 1) return address_generators.get(0).generateAddress();
// at this point we have multiple AddressGenerators installed
Address[] addrs = new Address[address_generators.size()];
for (int i = 0; i < addrs.length; i++) addrs[i] = address_generators.get(i).generateAddress();
for (int i = 0; i < addrs.length; i++) {
if (!(addrs[i] instanceof ExtendedUUID)) {
log.error(
"address generator %s does not subclass %s which is required if multiple address generators "
+ "are installed, removing it",
addrs[i].getClass().getSimpleName(), ExtendedUUID.class.getSimpleName());
addrs[i] = null;
}
}
ExtendedUUID uuid = null;
for (int i = 0; i < addrs.length; i++) { // we only have ExtendedUUIDs in addrs
if (addrs[i] != null) {
if (uuid == null) uuid = (ExtendedUUID) addrs[i];
else uuid.addContents((ExtendedUUID) addrs[i]);
}
}
return uuid != null ? uuid : UUID.randomUUID();
}
/**
* Disseminates cache information (UUID/IP adddress/port/name) to the given members
*
* @param current_mbrs The current members. Guaranteed to be non-null. This is a copy and can be
* modified.
* @param left_mbrs The members which left. These are excluded from dissemination. Can be null if
* no members left
* @param new_mbrs The new members that we need to disseminate the information to. Will be all
* members if null.
*/
protected void disseminateDiscoveryInformation(
List current_mbrs, List<Address> left_mbrs, List<Address> new_mbrs) {
if (new_mbrs == null || new_mbrs.isEmpty()) return;
if (local_addr != null) current_mbrs.remove(local_addr);
if (left_mbrs != null) current_mbrs.removeAll(left_mbrs);
// 1. Send information about <everyone - self - left_mbrs> to new_mbrs
Set<Address> info = new HashSet<>(current_mbrs);
for (Address addr : info) {
PhysicalAddress phys_addr =
(PhysicalAddress) down_prot.down(new Event(Event.GET_PHYSICAL_ADDRESS, addr));
if (phys_addr == null) continue;
boolean is_coordinator = isCoord(addr);
for (Address target : new_mbrs)
sendDiscoveryResponse(addr, phys_addr, UUID.get(addr), target, is_coordinator);
}
// 2. Send information about new_mbrs to <everyone - self - left_mbrs - new_mbrs>
Set<Address> targets = new HashSet<>(current_mbrs);
targets.removeAll(new_mbrs);
if (!targets.isEmpty()) {
for (Address addr : new_mbrs) {
PhysicalAddress phys_addr =
(PhysicalAddress) down_prot.down(new Event(Event.GET_PHYSICAL_ADDRESS, addr));
if (phys_addr == null) continue;
boolean is_coordinator = isCoord(addr);
for (Address target : targets)
sendDiscoveryResponse(addr, phys_addr, UUID.get(addr), target, is_coordinator);
}
}
}
@ManagedOperation(description = "Runs the discovery protocol to find initial members")
public String findInitialMembersAsString() {
List<PingData> results = findInitialMembers(null);
if (results == null || results.isEmpty()) return "<empty>";
StringBuilder sb = new StringBuilder();
for (PingData rsp : results) {
sb.append(rsp).append("\n");
}
return sb.toString();
}
@ManagedOperation(description = "Runs the discovery protocol to find all views")
public String findAllViewsAsString() {
List<PingData> rsps = findAllViews(null);
if (rsps == null || rsps.isEmpty()) return "<empty>";
StringBuilder sb = new StringBuilder();
for (PingData data : rsps) {
View v = data.getView();
if (v != null) sb.append(v).append("\n");
}
return sb.toString();
}
/**
* Merge all MergeData. All MergeData elements should be disjunct (both views and digests).
* However, this method is prepared to resolve duplicate entries (for the same member).
* Resolution strategy for views is to merge only 1 of the duplicate members. Resolution
* strategy for digests is to take the higher seqnos for duplicate digests.
*
* <p>After merging all members into a Membership and subsequent sorting, the first member of
* the sorted membership will be the new coordinator. This method has a lock on merge_rsps.
*
* @param merge_rsps A list of MergeData items. Elements with merge_rejected=true were removed
* before. Is guaranteed not to be null and to contain at least 1 member.
*/
private MergeData consolidateMergeData(List<MergeData> merge_rsps) {
long logical_time = 0; // for new_vid
List<View> subgroups =
new ArrayList<View>(11); // contains a list of Views, each View is a subgroup
Collection<Collection<Address>> sub_mbrships = new ArrayList<Collection<Address>>();
for (MergeData tmp_data : merge_rsps) {
View tmp_view = tmp_data.getView();
if (tmp_view != null) {
ViewId tmp_vid = tmp_view.getVid();
if (tmp_vid != null) {
// compute the new view id (max of all vids +1)
logical_time = Math.max(logical_time, tmp_vid.getId());
}
// merge all membership lists into one (prevent duplicates)
sub_mbrships.add(new ArrayList<Address>(tmp_view.getMembers()));
subgroups.add(tmp_view.copy());
}
}
// determine the new digest
Digest new_digest = consolidateDigests(merge_rsps, merge_rsps.size());
if (new_digest == null) return null;
// remove all members from the new member list that are not in the digest
Collection<Address> digest_mbrs = new_digest.getMembers();
for (Collection<Address> coll : sub_mbrships) coll.retainAll(digest_mbrs);
List<Address> merged_mbrs = gms.computeNewMembership(sub_mbrships);
// the new coordinator is the first member of the consolidated & sorted membership list
Address new_coord = merged_mbrs.isEmpty() ? null : merged_mbrs.get(0);
if (new_coord == null) return null;
// should be the highest view ID seen up to now plus 1
ViewId new_vid = new ViewId(new_coord, logical_time + 1);
// determine the new view
MergeView new_view = new MergeView(new_vid, merged_mbrs, subgroups);
if (log.isTraceEnabled())
log.trace(
gms.local_addr
+ ": consolidated view="
+ new_view
+ "\nconsolidated digest="
+ new_digest);
return new MergeData(gms.local_addr, new_view, new_digest);
}
private void process(List<Request> requests) {
if (requests.isEmpty()) return;
Request firstReq = requests.get(0);
switch (firstReq.type) {
case Request.JOIN:
case Request.JOIN_WITH_STATE_TRANSFER:
case Request.LEAVE:
case Request.SUSPECT:
impl.handleMembershipChange(requests);
break;
case Request.MERGE:
impl.merge(firstReq.views);
break;
default:
log.error("request " + firstReq.type + " is unknown; discarded");
}
}
/**
* Computes the next view. Returns a copy that has <code>old_mbrs</code> and <code>suspected_mbrs
* </code> removed and <code>new_mbrs</code> added.
*/
public View getNextView(
Collection<Address> new_mbrs,
Collection<Address> old_mbrs,
Collection<Address> suspected_mbrs) {
synchronized (members) {
ViewId view_id = view != null ? view.getViewId() : null;
if (view_id == null) {
log.error("view_id is null");
return null; // this should *never* happen !
}
long vid = Math.max(view_id.getId(), ltime) + 1;
ltime = vid;
Membership tmp_mbrs = tmp_members.copy(); // always operate on the temporary membership
tmp_mbrs.remove(suspected_mbrs);
tmp_mbrs.remove(old_mbrs);
tmp_mbrs.add(new_mbrs);
List<Address> mbrs = tmp_mbrs.getMembers();
Address new_coord = local_addr;
if (!mbrs.isEmpty()) new_coord = mbrs.get(0);
View v = new View(new_coord, vid, mbrs);
// Update membership (see DESIGN for explanation):
tmp_members.set(mbrs);
// Update joining list (see DESIGN for explanation)
if (new_mbrs != null) {
for (Address tmp_mbr : new_mbrs) {
if (!joining.contains(tmp_mbr)) joining.add(tmp_mbr);
}
}
// Update leaving list (see DESIGN for explanations)
if (old_mbrs != null) {
for (Address addr : old_mbrs) {
if (!leaving.contains(addr)) leaving.add(addr);
}
}
if (suspected_mbrs != null) {
for (Address addr : suspected_mbrs) {
if (!leaving.contains(addr)) leaving.add(addr);
}
}
return v;
}
}
public static void testPickNextN() {
List<Integer> list = Arrays.asList(1, 2, 3, 4);
List<Integer> result = Util.pickNext(list, 0, 1);
assert result.isEmpty();
result = Util.pickNext(list, 1, 1);
System.out.println("result = " + result);
assert result.size() == 1;
assert result.contains(2);
result = Util.pickNext(list, 3, 2);
System.out.println("result = " + result);
assert result.size() == 2;
assert result.contains(4) && result.contains(1);
result = Util.pickNext(list, 4, 5);
System.out.println("result = " + result);
assert result.size() == 3;
assert result.contains(1) && result.contains(2) && result.contains(3);
}
public static void testLeftMembers2() {
final Address a = Util.createRandomAddress(),
b = Util.createRandomAddress(),
c = Util.createRandomAddress(),
d = Util.createRandomAddress();
List<Address> v1 = new ArrayList<>();
v1.add(a);
v1.add(b);
v1.add(c);
v1.add(d);
List<Address> v2 = new ArrayList<>();
v2.add(c);
v2.add(d);
v2.add(a);
v2.add(b);
View one = new View(new ViewId(a, 1), v1), two = new View(new ViewId(b, 2), v2);
List<Address> left = View.leftMembers(one, two);
System.out.println("left = " + left);
assert left != null;
assert left.isEmpty();
}
protected <T> GroupRequest<T> cast(
final Collection<Address> dests,
Message msg,
RequestOptions options,
boolean block_for_results,
FutureListener<RspList<T>> listener)
throws Exception {
if (msg.getDest() != null && !(msg.getDest() instanceof AnycastAddress))
throw new IllegalArgumentException("message destination is non-null, cannot send message");
if (options != null) {
msg.setFlag(options.getFlags()).setTransientFlag(options.getTransientFlags());
if (options.getScope() > 0) msg.setScope(options.getScope());
}
List<Address> real_dests;
// we need to clone because we don't want to modify the original
if (dests != null) {
real_dests = new ArrayList<Address>();
for (Address dest : dests) {
if (dest instanceof SiteAddress || this.members.contains(dest)) {
if (!real_dests.contains(dest)) real_dests.add(dest);
}
}
} else real_dests = new ArrayList<Address>(members);
// if local delivery is off, then we should not wait for the message from the local member.
// therefore remove it from the membership
Channel tmp = channel;
if ((tmp != null && tmp.getDiscardOwnMessages())
|| msg.isTransientFlagSet(Message.TransientFlag.DONT_LOOPBACK)) {
if (local_addr == null) local_addr = tmp != null ? tmp.getAddress() : null;
if (local_addr != null) real_dests.remove(local_addr);
}
if (options != null && options.hasExclusionList()) {
Address[] exclusion_list = options.exclusionList();
for (Address excluding : exclusion_list) real_dests.remove(excluding);
}
// don't even send the message if the destination list is empty
if (log.isTraceEnabled()) log.trace("real_dests=" + real_dests);
if (real_dests.isEmpty()) {
if (log.isTraceEnabled()) log.trace("destination list is empty, won't send message");
return null;
}
if (options != null) {
boolean async = options.getMode() == ResponseMode.GET_NONE;
if (options.getAnycasting()) {
if (async) async_anycasts.incrementAndGet();
else sync_anycasts.incrementAndGet();
} else {
if (async) async_multicasts.incrementAndGet();
else sync_multicasts.incrementAndGet();
}
}
GroupRequest<T> req = new GroupRequest<T>(msg, corr, real_dests, options);
if (listener != null) req.setListener(listener);
if (options != null) {
req.setResponseFilter(options.getRspFilter());
req.setAnycasting(options.getAnycasting());
}
req.setBlockForResults(block_for_results);
req.execute();
return req;
}
/**
* Check whether the hashmap contains an entry e for <code>sender</code> (create if not). If
* e.received_msgs is null and <code>first</code> is true: create a new AckReceiverWindow(seqno)
* and add message. Set e.received_msgs to the new window. Else just add the message.
*/
protected void handleDataReceived(
Address sender, long seqno, short conn_id, boolean first, Message msg, Event evt) {
if (log.isTraceEnabled()) {
StringBuilder sb = new StringBuilder();
sb.append(local_addr).append(" <-- DATA(").append(sender).append(": #").append(seqno);
if (conn_id != 0) sb.append(", conn_id=").append(conn_id);
if (first) sb.append(", first");
sb.append(')');
log.trace(sb);
}
ReceiverEntry entry = getReceiverEntry(sender, seqno, first, conn_id);
if (entry == null) return;
if (conn_expiry_timeout > 0) entry.update();
Table<Message> win = entry.received_msgs;
boolean added = win.add(seqno, msg); // win is guaranteed to be non-null if we get here
num_msgs_received++;
if (added) {
int len = msg.getLength();
if (len > 0 && entry.incrementStable(len))
sendStableMessage(
sender, entry.recv_conn_id, win.getHighestDelivered(), win.getHighestReceived());
}
// An OOB message is passed up immediately. Later, when remove() is called, we discard it. This
// affects ordering !
// http://jira.jboss.com/jira/browse/JGRP-377
if (msg.isFlagSet(Message.OOB) && added) {
try {
up_prot.up(evt);
} catch (Throwable t) {
log.error("couldn't deliver OOB message " + msg, t);
}
}
final AtomicBoolean processing = win.getProcessing();
if (!processing.compareAndSet(false, true)) {
return;
}
// Try to remove as many messages as possible and pass them up.
// Prevents concurrent passing up of messages by different threads
// (http://jira.jboss.com/jira/browse/JGRP-198);
// this is all the more important once we have a concurrent stack
// (http://jira.jboss.com/jira/browse/JGRP-181),
// where lots of threads can come up to this point concurrently, but only 1 is allowed to pass
// at a time
// We *can* deliver messages from *different* senders concurrently, e.g. reception of P1, Q1,
// P2, Q2 can result in
// delivery of P1, Q1, Q2, P2: FIFO (implemented by UNICAST) says messages need to be delivered
// only in the
// order in which they were sent by their senders
boolean released_processing = false;
try {
while (true) {
List<Message> msgs =
win.removeMany(processing, true, max_msg_batch_size); // remove my own messages
if (msgs == null || msgs.isEmpty()) {
released_processing = true;
return;
}
for (Message m : msgs) {
// discard OOB msg: it has already been delivered
// (http://jira.jboss.com/jira/browse/JGRP-377)
if (m.isFlagSet(Message.OOB)) continue;
try {
up_prot.up(new Event(Event.MSG, m));
} catch (Throwable t) {
log.error("couldn't deliver message " + m, t);
}
}
}
} finally {
// processing is always set in win.remove(processing) above and never here ! This code is just
// a
// 2nd line of defense should there be an exception before win.remove(processing) sets
// processing
if (!released_processing) processing.set(false);
}
}
/**
* Broadcasts the new view and digest, and waits for acks from all members in the list given as
* argument. If the list is null, we take the members who are part of new_view
*/
public void castViewChange(
View new_view, Digest digest, JoinRsp jr, Collection<Address> newMembers) {
if (log.isTraceEnabled())
log.trace(local_addr + ": mcasting view " + new_view + " (" + new_view.size() + " mbrs)\n");
// Send down a local TMP_VIEW event. This is needed by certain layers (e.g. NAKACK) to compute
// correct digest
// in case client's next request (e.g. getState()) reaches us *before* our own view change
// multicast.
// Check NAKACK's TMP_VIEW handling for details
down_prot.up(new Event(Event.TMP_VIEW, new_view));
down_prot.down(new Event(Event.TMP_VIEW, new_view));
List<Address> ackMembers = new ArrayList<Address>(new_view.getMembers());
if (newMembers != null && !newMembers.isEmpty()) ackMembers.removeAll(newMembers);
Message view_change_msg = new Message(); // bcast to all members
GmsHeader hdr = new GmsHeader(GmsHeader.VIEW, new_view);
hdr.my_digest = digest;
view_change_msg.putHeader(this.id, hdr);
// If we're the only member the VIEW is broadcast to, let's simply install the view directly,
// without
// sending the VIEW multicast ! Or else N-1 members drop the multicast anyway...
if (local_addr != null && ackMembers.size() == 1 && ackMembers.get(0).equals(local_addr)) {
// we need to add the message to the retransmit window (e.g. in NAKACK), so (1) it can be
// retransmitted and
// (2) we increment the seqno (otherwise, we'd return an incorrect digest)
down_prot.down(new Event(Event.ADD_TO_XMIT_TABLE, view_change_msg));
impl.handleViewChange(new_view, digest);
} else {
if (!ackMembers.isEmpty()) ack_collector.reset(ackMembers);
down_prot.down(new Event(Event.MSG, view_change_msg));
try {
if (!ackMembers.isEmpty()) {
ack_collector.waitForAllAcks(view_ack_collection_timeout);
if (log.isTraceEnabled())
log.trace(
local_addr
+ ": received all "
+ ack_collector.expectedAcks()
+ " ACKs from members for view "
+ new_view.getVid());
}
} catch (TimeoutException e) {
if (log_collect_msgs && log.isWarnEnabled()) {
log.warn(
local_addr
+ ": failed to collect all ACKs (expected="
+ ack_collector.expectedAcks()
+ ") for view "
+ new_view.getViewId()
+ " after "
+ view_ack_collection_timeout
+ "ms, missing ACKs from "
+ ack_collector.printMissing());
}
}
}
if (jr != null && (newMembers != null && !newMembers.isEmpty())) {
ack_collector.reset(new ArrayList<Address>(newMembers));
for (Address joiner : newMembers) {
sendJoinResponse(jr, joiner);
}
try {
ack_collector.waitForAllAcks(view_ack_collection_timeout);
if (log.isTraceEnabled())
log.trace(
local_addr
+ ": received all ACKs ("
+ ack_collector.expectedAcks()
+ ") from joiners for view "
+ new_view.getVid());
} catch (TimeoutException e) {
if (log_collect_msgs && log.isWarnEnabled()) {
log.warn(
local_addr
+ ": failed to collect all ACKs (expected="
+ ack_collector.expectedAcks()
+ ") for unicast view "
+ new_view
+ " after "
+ view_ack_collection_timeout
+ "ms, missing ACKs from "
+ ack_collector.printMissing());
}
}
}
}
/**
* Sets the new view and sends a VIEW_CHANGE event up and down the stack. If the view is a
* MergeView (subclass of View), then digest will be non-null and has to be set before installing
* the view.
*/
public void installView(View new_view, Digest digest) {
ViewId vid = new_view.getVid();
List<Address> mbrs = new_view.getMembers();
ltime =
Math.max(
vid.getId(),
ltime); // compute the logical time, regardless of whether the view is accepted
// Discards view with id lower than or equal to our own. Will be installed without check if it
// is the first view
if (view != null) {
ViewId view_id = view.getViewId();
int rc = vid.compareToIDs(view_id);
if (rc <= 0) {
if (log.isWarnEnabled()
&& rc < 0
&& log_view_warnings) { // only scream if view is smaller, silently discard same views
log.warn(
local_addr
+ ": received view < current view;"
+ " discarding it (current vid: "
+ view_id
+ ", new vid: "
+ vid
+ ')');
}
return;
}
}
/* Check for self-inclusion: if I'm not part of the new membership, I just discard it.
This ensures that messages sent in view V1 are only received by members of V1 */
if (!mbrs.contains(local_addr)) {
if (log.isWarnEnabled() && log_view_warnings)
log.warn(local_addr + ": not member of view " + new_view.getViewId() + "; discarding it");
return;
}
if (digest != null) {
if (new_view instanceof MergeView) mergeDigest(digest);
else setDigest(digest);
}
if (log.isDebugEnabled()) log.debug(local_addr + ": installing view " + new_view);
Event view_event;
synchronized (members) {
view = new View(new_view.getVid(), new_view.getMembers());
view_event = new Event(Event.VIEW_CHANGE, new_view);
// Set the membership. Take into account joining members
if (!mbrs.isEmpty()) {
members.set(mbrs);
tmp_members.set(members);
joining.removeAll(mbrs); // remove all members in mbrs from joining
// remove all elements from 'leaving' that are not in 'mbrs'
leaving.retainAll(mbrs);
tmp_members.add(joining); // add members that haven't yet shown up in the membership
tmp_members.remove(
leaving); // remove members that haven't yet been removed from the membership
// add to prev_members
for (Address addr : mbrs) {
if (!prev_members.contains(addr)) prev_members.add(addr);
}
}
Address coord = determineCoordinator();
if (coord != null && coord.equals(local_addr) && !haveCoordinatorRole()) {
becomeCoordinator();
} else {
if (haveCoordinatorRole() && !local_addr.equals(coord)) {
becomeParticipant();
merge_ack_collector.reset(null); // we don't need this one anymore
}
}
}
// - Changed order of passing view up and down (http://jira.jboss.com/jira/browse/JGRP-347)
// - Changed it back (bela Sept 4 2007): http://jira.jboss.com/jira/browse/JGRP-564
// - Moved sending up view_event out of the synchronized block (bela Nov 2011)
down_prot.down(view_event); // needed e.g. by failure detector or UDP
up_prot.up(view_event);
List<Address> tmp_mbrs = new_view.getMembers();
ack_collector.retainAll(tmp_mbrs);
merge_ack_collector.retainAll(tmp_mbrs);
if (new_view instanceof MergeView) merger.forceCancelMerge();
if (stats) {
num_views++;
prev_views.add(new Tuple<View, Long>(new_view, System.currentTimeMillis()));
}
}
@SuppressWarnings("unchecked")
public Object down(Event evt) {
switch (evt.getType()) {
case Event.FIND_INITIAL_MBRS: // sent by GMS layer
return findMembers(null, true, false); // triggered by JOIN process (ClientGmsImpl)
case Event.FIND_MBRS:
return findMembers(
(List<Address>) evt.getArg(), false, false); // triggered by MERGE2/MERGE3
// case Event.TMP_VIEW:
case Event.VIEW_CHANGE:
List<Address> tmp;
View old_view = view;
view = (View) evt.getArg();
if ((tmp = view.getMembers()) != null) {
synchronized (members) {
members.clear();
members.addAll(tmp);
}
}
current_coord = !members.isEmpty() ? members.get(0) : null;
is_coord = current_coord != null && local_addr != null && current_coord.equals(local_addr);
Object retval = down_prot.down(evt);
if (send_cache_on_join && !isDynamic() && is_coord) {
List<Address> curr_mbrs, left_mbrs, new_mbrs;
synchronized (members) {
curr_mbrs = new ArrayList<>(members);
left_mbrs = old_view != null ? Util.leftMembers(old_view.getMembers(), members) : null;
new_mbrs = old_view != null ? Util.newMembers(old_view.getMembers(), members) : null;
}
startCacheDissemination(curr_mbrs, left_mbrs, new_mbrs); // separate task
}
return retval;
case Event.BECOME_SERVER: // called after client has joined and is fully working group member
down_prot.down(evt);
is_server = true;
return null;
case Event.SET_LOCAL_ADDRESS:
local_addr = (Address) evt.getArg();
return down_prot.down(evt);
case Event.CONNECT:
case Event.CONNECT_WITH_STATE_TRANSFER:
case Event.CONNECT_USE_FLUSH:
case Event.CONNECT_WITH_STATE_TRANSFER_USE_FLUSH:
is_leaving = false;
cluster_name = (String) evt.getArg();
Object ret = down_prot.down(evt);
handleConnect();
return ret;
case Event.DISCONNECT:
is_leaving = true;
handleDisconnect();
return down_prot.down(evt);
default:
return down_prot.down(evt); // Pass on to the layer below us
}
}
/** Runs the merge protocol as a leader */
protected void _run(MergeId new_merge_id, final Collection<Address> coordsCopy)
throws Exception {
boolean success = setMergeId(null, new_merge_id);
if (!success) {
log.warn("failed to set my own merge_id (" + merge_id + ") to " + new_merge_id);
return;
}
if (log.isDebugEnabled())
log.debug(
gms.local_addr
+ ": merge task "
+ merge_id
+ " started with "
+ coords.keySet().size()
+ " coords");
/* 2. Fetch the current Views/Digests from all subgroup coordinators */
success = getMergeDataFromSubgroupCoordinators(coords, new_merge_id, gms.merge_timeout);
List<Address> missing = null;
if (!success) {
missing = merge_rsps.getMissing();
if (log.isDebugEnabled())
log.debug(
"merge leader "
+ gms.local_addr
+ " did not get responses from all "
+ coords.keySet().size()
+ " partition coordinators; missing responses from "
+ missing.size()
+ " members, removing them from the merge");
merge_rsps.remove(missing);
}
/* 3. Remove null or rejected merge responses from merge_rsp and coords (so we'll send the new view
* only to members who accepted the merge request) */
if (missing != null && !missing.isEmpty()) {
coords.keySet().removeAll(missing);
coordsCopy.removeAll(missing);
}
removeRejectedMergeRequests(coords.keySet());
if (merge_rsps.size() == 0)
throw new Exception("did not get any merge responses from partition coordinators");
if (!coords
.keySet()
.contains(
gms.local_addr)) // another member might have invoked a merge req on us before we got
// there...
throw new Exception("merge leader rejected merge request");
/* 4. Combine all views and digests into 1 View/1 Digest */
List<MergeData> merge_data = new ArrayList<MergeData>(merge_rsps.getResults().values());
MergeData combined_merge_data = consolidateMergeData(merge_data);
if (combined_merge_data == null) throw new Exception("could not consolidate merge");
/* 4. Send the new View/Digest to all coordinators (including myself). On reception, they will
install the digest and view in all of their subgroup members */
if (log.isDebugEnabled())
log.debug(
gms.local_addr
+ ": installing merge view "
+ combined_merge_data.view.getViewId()
+ " ("
+ combined_merge_data.view.size()
+ " members) in "
+ coords.keySet().size()
+ " coords");
sendMergeView(coords.keySet(), combined_merge_data, new_merge_id);
}
Address determineCoordinator() {
List<Address> mbrs = my_view != null ? my_view.getMembers() : null;
if (mbrs == null) return null;
if (!mbrs.isEmpty()) return mbrs.iterator().next();
return null;
}
