/**
* 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;
}
}
/**
* Callback method <br>
* Called by the ProtocolStack when a message is received.
*
* @param evt the event carrying the message from the protocol stack
*/
public Object up(Event evt) {
switch (evt.getType()) {
case Event.MSG:
Message msg = (Message) evt.getArg();
if (stats) {
received_msgs++;
received_bytes += msg.getLength();
}
// discard local messages (sent by myself to me)
if (discard_own_messages
&& local_addr != null
&& msg.getSrc() != null
&& local_addr.equals(msg.getSrc())) return null;
break;
case Event.VIEW_CHANGE:
View tmp = (View) evt.getArg();
if (tmp instanceof MergeView) my_view = new View(tmp.getViewId(), tmp.getMembers());
else my_view = tmp;
// Bela&Vladimir Oct 27th,2006 (JGroups 2.4): we need to set connected=true because a client
// can
// call channel.getView() in viewAccepted() callback invoked on this thread (see
// Event.VIEW_CHANGE handling below)
// not good: we are only connected when we returned from connect() - bela June 22 2007
// Changed: when a channel gets a view of which it is a member then it should be
// connected even if connect() hasn't returned yet ! (bela Noc 2010)
if (state != State.CONNECTED) state = State.CONNECTED;
break;
case Event.CONFIG:
Map<String, Object> cfg = (Map<String, Object>) evt.getArg();
if (cfg != null) {
if (cfg.containsKey("state_transfer")) {
state_transfer_supported = (Boolean) cfg.get("state_transfer");
}
if (cfg.containsKey("flush_supported")) {
flush_supported = (Boolean) cfg.get("flush_supported");
}
}
break;
case Event.GET_STATE_OK:
StateTransferResult result = (StateTransferResult) evt.getArg();
if (up_handler != null) {
try {
Object retval = up_handler.up(evt);
state_promise.setResult(new StateTransferResult());
return retval;
} catch (Throwable t) {
state_promise.setResult(new StateTransferResult(t));
}
}
if (receiver != null) {
try {
if (result.hasBuffer()) {
byte[] tmp_state = result.getBuffer();
ByteArrayInputStream input = new ByteArrayInputStream(tmp_state);
receiver.setState(input);
}
state_promise.setResult(result);
} catch (Throwable t) {
state_promise.setResult(new StateTransferResult(t));
}
}
break;
case Event.STATE_TRANSFER_INPUTSTREAM_CLOSED:
state_promise.setResult((StateTransferResult) evt.getArg());
break;
case Event.STATE_TRANSFER_INPUTSTREAM:
// Oct 13,2006 moved to down() when Event.STATE_TRANSFER_INPUTSTREAM_CLOSED is received
// state_promise.setResult(is != null? Boolean.TRUE : Boolean.FALSE);
if (up_handler != null) return up_handler.up(evt);
InputStream is = (InputStream) evt.getArg();
if (is != null && receiver != null) {
try {
receiver.setState(is);
} catch (Throwable t) {
throw new RuntimeException("failed calling setState() in state requester", t);
}
}
break;
case Event.STATE_TRANSFER_OUTPUTSTREAM:
if (receiver != null && evt.getArg() != null) {
try {
receiver.getState((OutputStream) evt.getArg());
} catch (Exception e) {
throw new RuntimeException("failed calling getState() in state provider", e);
}
}
break;
case Event.GET_LOCAL_ADDRESS:
return local_addr;
default:
break;
}
// If UpHandler is installed, pass all events to it and return (UpHandler is e.g. a building
// block)
if (up_handler != null) return up_handler.up(evt);
if (receiver != null) return invokeCallback(evt.getType(), evt.getArg());
return null;
}
/**
* 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()));
}
}
/**
* 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());
}
}
}
}
@ManagedAttribute
public String getView() {
return view != null ? view.getViewId().toString() : "null";
}
public ViewId getViewId() {
return view != null ? view.getViewId() : null;
}
