@Override
public State<?, ?> handle(
ClusterContext context, Message<ClusterMessage> message, MessageHolder outgoing)
throws Throwable {
List<URI> discoveredInstances = context.getDiscoveredInstances();
switch (message.getMessageType()) {
case configurationResponse:
{
context.timeouts.cancelTimeout("discovery");
ClusterMessage.ConfigurationResponseState state = message.getPayload();
context.getLogger(ClusterState.class).info("Joining cluster " + state.getClusterName());
if (!context.getConfiguration().getName().equals(state.getClusterName())) {
context
.getLogger(ClusterState.class)
.warn(
"Joined cluster name is different than "
+ "the one configured. Expected "
+ context.getConfiguration().getName()
+ ", got "
+ state.getClusterName()
+ ".");
}
List<URI> memberList = new ArrayList<URI>(state.getMembers());
context.learnerContext.setLastDeliveredInstanceId(
state.getLatestReceivedInstanceId().getId());
context.learnerContext.learnedInstanceId(state.getLatestReceivedInstanceId().getId());
context.proposerContext.nextInstanceId =
state.getLatestReceivedInstanceId().getId() + 1;
context.acquiredConfiguration(memberList, state.getRoles());
if (!memberList.contains(context.me)) {
context
.getLogger(ClusterState.class)
.info(
String.format(
"%s joining:%s, " + "last delivered:%d",
context.me.toString(),
context.getConfiguration().toString(),
state.getLatestReceivedInstanceId().getId()));
ClusterMessage.ConfigurationChangeState newState =
new ClusterMessage.ConfigurationChangeState();
newState.join(context.me);
// Let the coordinator propose this if possible
URI coordinator = state.getRoles().get(ClusterConfiguration.COORDINATOR);
if (coordinator != null) {
outgoing.offer(to(ProposerMessage.propose, coordinator, newState));
} else {
outgoing.offer(
to(
ProposerMessage.propose,
new URI(message.getHeader(Message.FROM)),
newState));
}
context
.getLogger(ClusterState.class)
.debug("Setup join timeout for " + message.getHeader(Message.CONVERSATION_ID));
context.timeouts.setTimeout(
"join",
timeout(
ClusterMessage.joiningTimeout,
message,
new URI(message.getHeader(Message.FROM))));
return joining;
} else {
// Already in (probably due to crash of this server previously), go to entered state
context.joined();
outgoing.offer(internal(ClusterMessage.joinResponse, context.getConfiguration()));
return entered;
}
}
case configurationTimeout:
{
ClusterMessage.ConfigurationTimeoutState state = message.getPayload();
if (state.getRemainingPings() > 0) {
// Send out requests again
for (URI potentialClusterInstanceUri : context.getJoiningInstances()) {
outgoing.offer(
to(ClusterMessage.configurationRequest, potentialClusterInstanceUri));
}
context.timeouts.setTimeout(
"join",
timeout(
ClusterMessage.configurationTimeout,
message,
new ClusterMessage.ConfigurationTimeoutState(state.getRemainingPings() - 1)));
} else {
// No responses
// Check if we picked up any other instances' requests during this phase
if (!discoveredInstances.isEmpty()) {
Collections.sort(discoveredInstances);
/*
* The assumption here is that the lowest in the list of discovered instances
* will create the cluster. Keep in mind that this is run on all instances so
* everyone will pick the same one.
* If the one picked up is configured to not init a cluster then the timeout
* set in else{} will take care of that.
*/
if (discoveredInstances.get(0).compareTo(context.getMe()) >= 0) {
discoveredInstances.clear();
// I'm supposed to create the cluster - fail the join
outgoing.offer(
internal(
ClusterMessage.joinFailure,
new TimeoutException("Join failed, timeout waiting for configuration")));
return start;
} else {
discoveredInstances.clear();
// Someone else is supposed to create the cluster - restart the join discovery
for (URI potentialClusterInstanceUri : context.getJoiningInstances()) {
outgoing.offer(
to(ClusterMessage.configurationRequest, potentialClusterInstanceUri));
}
context.timeouts.setTimeout(
"discovery",
timeout(
ClusterMessage.configurationTimeout,
message,
new ClusterMessage.ConfigurationTimeoutState(4)));
}
} else {
// Join failed
outgoing.offer(
internal(
ClusterMessage.joinFailure,
new TimeoutException("Join failed, timeout waiting for configuration")));
return start;
}
}
return this;
}
case configurationRequest:
{
// We're listening for existing clusters, but if all instances start up at the same time
// and look for each other, this allows us to pick that up
URI joiningInstanceUri = new URI(message.getHeader(Message.FROM));
if (!discoveredInstances.contains(joiningInstanceUri)) {
discoveredInstances.add(joiningInstanceUri);
}
}
}
return this;
}
