Address comments.

fdbclient/MonitorLeader.actor.cpp

@@ -547,31 +547,31 @@ ClientLeaderRegInterface::ClientLeaderRegInterface(INetwork* local) {
 // This function contacts a coordinator coord to ask who is its nominee.
 // Note: for coordinators whose NetworkAddress is parsed out of a hostname, a connection failure will cause this actor
 // to throw `coordinators_changed()` error
-ACTOR Future<Void> monitorNominee(
+ACTOR Future<Void> monitorNominee(Key key,
-    Key key,
+                                  ClientLeaderRegInterface coord,
-    ClientLeaderRegInterface coord,
+                                  AsyncTrigger* nomineeChange,
-    AsyncTrigger* nomineeChange,
+                                  Optional<LeaderInfo>* info,
-    Optional<LeaderInfo>* info,
+                                  Optional<Hostname> hostname = Optional<Hostname>()) {
-    Optional<Hostname> hostname = Optional<Hostname>(),
-    Reference<IClusterConnectionRecord> connRecord = Reference<IClusterConnectionRecord>()) {
 	loop {
-		if (connRecord.isValid() && connRecord->hasUnresolvedHostnames()) {
-			wait(connRecord->resolveHostnames());
-		}
 		state Optional<LeaderInfo> li;
 
 		if (coord.getLeader.getEndpoint().getPrimaryAddress().fromHostname) {
 			state ErrorOr<Optional<LeaderInfo>> rep =
 			    wait(coord.getLeader.tryGetReply(GetLeaderRequest(key, info->present() ? info->get().changeID : UID()),
 			                                     TaskPriority::CoordinationReply));
-			if (rep.isError() && rep.getError().code() == error_code_request_maybe_delivered) {
+			if (rep.isError()) {
 				// Connecting to nominee failed, most likely due to connection failed.
-				TraceEvent("CoordnitorChangedMonitorNominee")
+				TraceEvent("MonitorNomineeError")
 				    .detail("Hostname", hostname.present() ? hostname.get().toString() : "UnknownHostname")
-				    .detail("OldAddr", coord.getLeader.getEndpoint().getPrimaryAddress().toString());
+				    .detail("OldAddr", coord.getLeader.getEndpoint().getPrimaryAddress().toString())
-				// 50 milliseconds delay to prevent tight resolving loop due to outdated DNS cache
+				    .error(rep.getError());
-				wait(delay(0.05));
+				if (rep.getError().code() == error_code_request_maybe_delivered) {
-				throw coordinators_changed();
+					// 50 milliseconds delay to prevent tight resolving loop due to outdated DNS cache
+					wait(delay(0.05));
+					throw coordinators_changed();
+				} else {
+					throw rep.getError();
+				}
 			} else if (rep.present()) {
 				li = rep.get();
 			}
@@ -681,12 +681,8 @@ ACTOR Future<MonitorLeaderInfo> monitorLeaderOneGeneration(Reference<IClusterCon
 			if (r != connRecord->getConnectionString().networkAddressToHostname.end()) {
 				hostname = r->second;
 			}
-			actors.push_back(monitorNominee(coordinators.clusterKey,
+			actors.push_back(monitorNominee(
-			                                coordinators.clientLeaderServers[i],
+			    coordinators.clusterKey, coordinators.clientLeaderServers[i], &nomineeChange, &nominees[i], hostname));
-			                                &nomineeChange,
-			                                &nominees[i],
-			                                hostname,
-			                                connRecord));
 		}
 		allActors = waitForAll(actors);
 
@@ -725,7 +721,7 @@ ACTOR Future<MonitorLeaderInfo> monitorLeaderOneGeneration(Reference<IClusterCon
 				wait(nomineeChange.onTrigger() || allActors);
 			} catch (Error& e) {
 				if (e.code() == error_code_coordinators_changed) {
-					connRecord->getMutableConnectionString()->resetToUnresolved();
+					connRecord->getConnectionString().resetToUnresolved();
 					break;
 				} else {
 					throw e;
@@ -919,7 +915,7 @@ ACTOR Future<Void> monitorLeaderAndGetClientInfo(Key clusterKey,
 			if (e.code() == error_code_coordinators_changed) {
 				coordinatorsChanged->trigger();
 			}
-			return Void();
+			throw e;
 		}
 	}
 }
@@ -1088,7 +1084,7 @@ ACTOR Future<Void> monitorProxies(
 			}
 		} catch (Error& e) {
 			if (e.code() == error_code_coordinators_changed) {
-				info.intermediateConnRecord->getMutableConnectionString()->resetToUnresolved();
+				info.intermediateConnRecord->getConnectionString().resetToUnresolved();
 			} else {
 				throw e;
 			}

fdbserver/CoordinatedState.actor.cpp

@@ -359,9 +359,5 @@ Future<Void> MovableCoordinatedState::setExclusive(Value v) {
 	return impl->setExclusive(v);
 }
 Future<Void> MovableCoordinatedState::move(ClusterConnectionString const& nc) {
-	// We assume the new connection string contains only IP addresses. Even `coordinators` command in fdbcli is going to
-	// support hostnames, those hostnames should have been resolved in place and will be treated as IP address
-	// afterwards, i.e. no automatic re-resolve as that of the hostname used in cluster file.
-	ASSERT(nc.hostnames.size() == 0);
 	return MovableCoordinatedStateImpl::move(impl.get(), nc);
 }

fdbserver/Coordination.actor.cpp

@@ -268,7 +268,7 @@ ACTOR Future<Void> remoteMonitorLeader(int* clientCount,
                                        Reference<AsyncVar<Optional<LeaderInfo>>> currentElectedLeader,
                                        ElectionResultRequest req,
                                        Reference<AsyncVar<Void>> coordinatorsChanged) {
-	state bool _coordinatorsChanged = false;
+	state bool coordinatorsChangeDetected = false;
 	state Future<Void> coordinatorsChangedOnChange = coordinatorsChanged->onChange();
 	state Future<Void> currentElectedLeaderOnChange = currentElectedLeader->onChange();
 	++(*clientCount);
@@ -281,14 +281,14 @@ ACTOR Future<Void> remoteMonitorLeader(int* clientCount,
 			}
 			when(wait(coordinatorsChangedOnChange)) {
 				coordinatorsChangedOnChange = coordinatorsChanged->onChange();
-				_coordinatorsChanged = true;
+				coordinatorsChangeDetected = true;
 				break;
 			}
 			when(wait(delayJittered(SERVER_KNOBS->CLIENT_REGISTER_INTERVAL))) { break; }
 		}
 	}
 
-	if (_coordinatorsChanged) {
+	if (coordinatorsChangeDetected) {
 		req.reply.sendError(coordinators_changed());
 	} else {
 		req.reply.send(currentElectedLeader->get());

fdbserver/worker.actor.cpp

@@ -2511,7 +2511,7 @@ ACTOR Future<MonitorLeaderInfo> monitorLeaderWithDelayedCandidacyImplOneGenerati
 			successIndex = index;
 		} else {
 			if (leader.isError() && leader.getError().code() == error_code_coordinators_changed) {
-				info.intermediateConnRecord->getMutableConnectionString()->resetToUnresolved();
+				info.intermediateConnRecord->getConnectionString().resetToUnresolved();
 				throw coordinators_changed();
 			}
 			index = (index + 1) % addrs.size();
@@ -2539,7 +2539,7 @@ ACTOR Future<Void> monitorLeaderWithDelayedCandidacyImplInternal(Reference<IClus
 			info = _info;
 		} catch (Error& e) {
 			if (e.code() == error_code_coordinators_changed) {
-				info.intermediateConnRecord->getMutableConnectionString()->resetToUnresolved();
+				info.intermediateConnRecord->getConnectionString().resetToUnresolved();
 			} else {
 				throw e;
 			}

fdbserver/workloads/SpecialKeySpaceCorrectness.actor.cpp

@@ -1052,11 +1052,10 @@ struct SpecialKeySpaceCorrectnessWorkload : TestWorkload {
 					Optional<Value> res = wait(tx->get(coordinatorsKey));
 					ASSERT(res.present()); // Otherwise, database is in a bad state
 					state ClusterConnectionString csNew(res.get().toString());
-					ASSERT(csNew.coordinators().size() + csNew.hostnames.size() ==
-					       old_coordinators_processes.size() + 1);
 					if (csNew.hasUnresolvedHostnames) {
 						wait(csNew.resolveHostnames());
 					}
+					ASSERT(csNew.coordinators().size() == old_coordinators_processes.size() + 1);
 					// verify the coordinators' addresses
 					for (const auto& network_address : csNew.coordinators()) {
 						std::string address_str = network_address.toString();