/**
* @param views Guaranteed to be non-null and to have >= 2 members, or else this thread would
* not be started
*/
public synchronized void start(Map<Address, View> views) {
if (thread == null || thread.isAlive()) {
this.coords.clear();
// now remove all members which don't have us in their view, so RPCs won't block (e.g.
// FLUSH)
// https://jira.jboss.org/browse/JGRP-1061
sanitizeViews(views);
// Add all different coordinators of the views into the hashmap and sets their members:
Collection<Address> coordinators = Util.determineMergeCoords(views);
for (Address coord : coordinators) {
View view = views.get(coord);
if (view != null) this.coords.put(coord, new ArrayList<Address>(view.getMembers()));
}
// For the merge participants which are not coordinator, we simply add them, and the
// associated
// membership list consists only of themselves
Collection<Address> merge_participants = Util.determineMergeParticipants(views);
merge_participants.removeAll(coordinators);
for (Address merge_participant : merge_participants) {
Collection<Address> tmp = new ArrayList<Address>();
tmp.add(merge_participant);
coords.putIfAbsent(merge_participant, tmp);
}
thread = gms.getThreadFactory().newThread(this, "MergeTask");
thread.setDaemon(true);
thread.start();
}
}
@SuppressWarnings("unchecked")
private static void check(final int num_expected_msgs, Collection<Integer>... lists) {
for (Collection<Integer> list : lists) {
System.out.println("list: " + list);
}
for (Collection<Integer> list : lists) {
Collection<Integer> missing = new TreeSet<Integer>();
if (list.size() != num_expected_msgs) {
for (int i = 0; i < num_expected_msgs; i++) missing.add(i);
missing.removeAll(list);
assert list.size() == num_expected_msgs
: "expected "
+ num_expected_msgs
+ " elements, but got "
+ list.size()
+ " (list="
+ list
+ "), missing="
+ missing;
}
}
}
/** 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);
}
