sashapolo commented on code in PR #722:
URL: https://github.com/apache/ignite-3/pull/722#discussion_r845240989
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modules/cluster-management/src/main/java/org/apache/ignite/internal/cluster/management/ClusterManagementGroupManager.java:
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@@ -133,90 +138,377 @@ public void initCluster(Collection<String>
metaStorageNodeNames, Collection<Stri
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
- throw new IgniteInternalException("Interrupted while initializing
the cluster", e);
+ throw new InitException("Interrupted while initializing the
cluster", e);
} catch (ExecutionException e) {
- throw new IgniteInternalException("Unable to initialize the
cluster", e.getCause());
+ throw new InitException("Unable to initialize the cluster",
e.getCause());
} finally {
busyLock.leaveBusy();
}
}
- private void handleInit(CmgInitMessage msg, NetworkAddress addr, long
correlationId) throws NodeStoppingException {
- List<ClusterNode> nodes = resolveNodes(clusterService, msg.cmgNodes());
+ @Override
+ public void start() {
+ var messageHandlerFactory = new CmgMessageHandlerFactory(busyLock,
msgFactory, clusterService);
+
+ // register the ClusterState handler first, because local state
recovery might send such messages
+ clusterService.messagingService().addMessageHandler(
+ CmgMessageGroup.class,
+ messageHandlerFactory.wrapHandler((message, senderAddr,
correlationId) -> {
+ if (message instanceof ClusterStateMessage) {
+ assert correlationId != null;
- raftManager.prepareRaftGroup(CMG_RAFT_GROUP_NAME, nodes,
CmgRaftGroupListener::new)
- .whenComplete((service, e) -> {
- MessagingService messagingService =
clusterService.messagingService();
+ handleClusterState((ClusterStateMessage) message,
senderAddr, correlationId);
+ }
+ })
+ );
- if (e == null) {
- ClusterNode leader = getLeader(service);
+ raftService = recoverLocalState();
- ClusterNode thisNode =
clusterService.topologyService().localMember();
+ // register the Init handler second in order to handle the command
differently, depending on the local state
+ clusterService.messagingService().addMessageHandler(
+ CmgMessageGroup.class,
+ messageHandlerFactory.wrapHandler((message, senderAddr,
correlationId) -> {
+ if (message instanceof CancelInitMessage) {
+ handleCancelInit((CancelInitMessage) message);
+ } else if (message instanceof CmgInitMessage) {
+ assert correlationId != null;
- messagingService.respond(addr,
successResponse(msgFactory), correlationId);
+ handleInit((CmgInitMessage) message, senderAddr,
correlationId);
+ }
+ })
+ );
- if (leader.equals(thisNode)) {
- broadcastClusterState(msg.metaStorageNodes());
+ restComponent.registerHandlers(routes ->
+ routes.post(REST_ENDPOINT, APPLICATION_JSON.toString(), new
InitCommandHandler(clusterInitializer))
+ );
+ }
+
+ /**
+ * Extracts the local state (if any) and starts the CMG.
+ *
+ * @return Future that resolves into the CMG Raft service or {@code null}
the local state is empty.
+ */
+ @Nullable
+ private CompletableFuture<CmgRaftService> recoverLocalState() {
+ Collection<String> cmgNodes;
+
+ try {
+ cmgNodes = localStateStorage.cmgNodeNames().get();
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+
+ throw new IgniteInternalException("Interrupted while retrieving
local CMG state", e);
+ } catch (ExecutionException e) {
+ throw new IgniteInternalException("Error while retrieving local
CMG state", e);
+ }
+
+ if (cmgNodes.isEmpty()) {
+ return null;
+ }
+
+ return startCmgRaftService(cmgNodes)
+ .thenCompose(service -> {
+ log.info("Local CMG state recovered");
+
+ return service.isCurrentNodeLeader()
+ .thenCompose(isLeader -> {
+ if (isLeader) {
+ return service.readClusterState()
+ // Raft state might not have been
initialized in case of leader failure during cluster init
+ .thenCompose(state -> state ==
null ? completedFuture(null) : onLeaderElected(service, state));
+ } else {
+ return completedFuture(null);
+ }
+ })
+ .thenApply(v -> service);
+ });
+ }
+
+ /**
+ * Handles the Init command.
+ *
+ * <p>This method needs to take the following possibilities into account,
depending on the local state and the Raft state:
+ * <ol>
+ * <li>No local state found - this means that the current node has
never been initialized before.</li>
+ * <li>Local state found, but no CMG state present in the Raft storage
- this means that the node has failed somewhere during
+ * the init process. In this case we need to check the consistency of
the local state and the received message and complete
+ * the init process.</li>
+ * <li>Local state found and CMG state is present in the Raft storage
- this means that the node has been initialized successfully
+ * and a user may be retrying the init in case the successful response
was lost. To make the init message idempotent
+ * we simply check that the Raft state and the received message are
the same.</li>
+ * </ol>
+ */
+ private void handleInit(CmgInitMessage msg, NetworkAddress addr, long
correlationId) {
+ var newState = new ClusterState(msg.cmgNodes(),
msg.metaStorageNodes());
+
+ CompletableFuture<CmgRaftService> raftService = this.raftService;
+
+ // This future is needed to add a completion listener at the end of
the method
+ CompletableFuture<?> resultHook;
+
+ if (raftService == null) {
+ // Raft service has not been started
+ log.info("Init command received, starting the CMG: " + newState);
+
+ raftService = initCmgRaftService(newState);
+
+ this.raftService = raftService;
+
+ resultHook = raftService;
+ } else {
+ // Raft service has been started, which means that this node has
already received an init command at least once, but
+ // we still need to check that the initialization has completed
successfully.
+ log.info("Init command received, but the CMG has already been
started");
+
+ resultHook = raftService.thenCompose(service ->
+ service.readClusterState()
+ .thenCompose(state -> {
+ if (state == null) {
+ // Raft state is empty, perform
re-initialization
+ log.info("CMG state is missing, completing
initialization");
+
+ if
(service.nodeNames().equals(newState.cmgNodes())) {
+ return service.isCurrentNodeLeader()
+
.thenCompose(isCurrentNodeLeader ->
+ isCurrentNodeLeader ?
initCmgState(service, newState) : completedFuture(null));
+ } else {
+ throw new
IllegalStateException(String.format(
+ "CMG has already been
initialized with %s, but the new state is different: %s",
+ service.nodeNames(),
newState.cmgNodes()
+ ));
+ }
+ } else {
+ // Node is fully initialized, just check
some invariants
+ log.info("Node has already been
initialized");
+
+ if (state.equals(newState)) {
+ return completedFuture(null);
+ } else {
+ throw new
IllegalStateException(String.format(
+ "CMG has already been
initialized with %s, but the new state is different: %s",
+ state, newState
+ ));
+ }
+ }
+ }));
+ }
+
+ resultHook.whenComplete((v, e) -> {
+ NetworkMessage response = e == null
+ ? msgFactory.initCompleteMessage().build()
+ :
msgFactory.initErrorMessage().cause(e.getMessage()).build();
+
+ clusterService.messagingService().respond(addr, response,
correlationId);
+ });
+ }
+
+ /**
+ * Starts the CMG Raft service and writes the given {@code state} to the
storage.
+ */
+ private CompletableFuture<CmgRaftService> initCmgRaftService(ClusterState
state) {
+ return localStateStorage.putCmgNodeNames(state.cmgNodes())
+ .thenCompose(v -> startCmgRaftService(state.cmgNodes()))
+ .thenCompose(service -> service.isCurrentNodeLeader()
+ .thenCompose(isLeader -> isLeader ?
initCmgState(service, state) : completedFuture(null))
+ .thenApply(v -> service));
+ }
+
+ /**
+ * Writes the given state to the CMG's STM and executes some necessary
on-leader logic.
+ */
+ private CompletableFuture<Void> initCmgState(CmgRaftService service,
ClusterState state) {
+ return service.writeClusterState(state).thenCompose(v ->
onLeaderElected(service, state));
+ }
+
+ /**
+ * Executes the following actions when a CMG leader is elected.
+ * <ol>
+ * <li>Updates the logical topology in case some nodes have gone
offline during leader election.</li>
+ * <li>Broadcasts the current CMG state to all nodes in the physical
topology.</li>
+ * </ol>
+ */
+ private CompletableFuture<Void> onLeaderElected(CmgRaftService service,
ClusterState state) {
+ return updateLogicalTopology(service)
+ .thenRun(() -> {
+
clusterService.topologyService().addEventHandler(cmgLeaderTopologyEventHandler(service));
+
+ sendClusterState(state,
clusterService.topologyService().allMembers());
+ });
+ }
+
+ /**
+ * This method must be executed upon CMG leader election in order to
regain logical topology consistency in case some nodes left the
+ * physical topology during the election. New node will be added
automatically after the new leader broadcasts the current cluster
+ * state.
+ */
+ private CompletableFuture<Void> updateLogicalTopology(CmgRaftService
service) {
+ return service.logicalTopology()
+ .thenAccept(logicalTopology -> {
+ Collection<String> physicalTopologyIds =
clusterService.topologyService().allMembers()
+ .stream()
+ .map(ClusterNode::id)
+ .collect(toSet());
+
+ for (ClusterNode node : logicalTopology) {
+ if (!physicalTopologyIds.contains(node.id())) {
+ removeNodeFromLogicalTopology(service, node);
}
- } else {
- messagingService.respond(addr,
errorResponse(msgFactory, e), correlationId);
}
});
}
- private void handleCancelInit(CancelInitMessage msg) throws
NodeStoppingException {
+ private void handleCancelInit(CancelInitMessage msg) {
log.info("CMG initialization cancelled, reason: " + msg.reason());
- raftManager.stopRaftGroup(CMG_RAFT_GROUP_NAME);
+ destroyCmg();
+ }
+
+ /**
+ * Completely destroys the local CMG Raft service.
+ */
+ private void destroyCmg() {
+ try {
+ CompletableFuture<CmgRaftService> raftService = this.raftService;
+
+ if (raftService != null) {
+ raftService.cancel(true);
+ }
+
+ raftManager.stopRaftGroup(CMG_RAFT_GROUP_NAME);
- // TODO: drop the Raft storage as well,
https://issues.apache.org/jira/browse/IGNITE-16471
+ if (raftStorage.isStarted()) {
+ raftStorage.destroy();
+ }
+
+ localStateStorage.clear().get();
+
+ this.raftService = null;
+ } catch (Exception e) {
+ throw new IgniteInternalException("Error when cleaning the CMG
state", e);
+ }
}
- private void handleClusterState(ClusterStateMessage msg) {
- metastorageNodes.complete(msg.metastorageNodes());
+ /**
+ * Handler for the {@link ClusterStateMessage}.
+ */
+ private void handleClusterState(ClusterStateMessage msg, NetworkAddress
addr, long correlationId) {
+ clusterService.messagingService().respond(addr,
msgFactory.clusterStateReceivedMessage().build(), correlationId);
+
+ var state = new ClusterState(msg.cmgNodes(), msg.metaStorageNodes());
+
+ CompletableFuture<CmgRaftService> raftService = this.raftService;
+
+ if (raftService == null) {
+ raftService = initCmgRaftService(state);
+ } else {
+ // Raft service might have been started on wrong CMG nodes,
because CMG state can change while a node is offline. In this
+ // case we need to re-create the service.
+ raftService = raftService.thenCompose(service -> {
+ if (service.nodeNames().equals(state.cmgNodes())) {
+ return completedFuture(service);
+ } else {
+ if (log.isInfoEnabled()) {
+ log.info("CMG has been started on {}, but the cluster
state is different: {}. "
+ + "Re-creating the CMG Raft service",
service.nodeNames(), state.cmgNodes());
+ }
+
+ destroyCmg();
+
+ return initCmgRaftService(state);
+ }
+ });
+ }
+
+ raftService
+ .thenCompose(CmgRaftService::joinCluster)
+ .thenRun(() ->
metaStorageNodes.complete(state.metaStorageNodes()));
+
+ this.raftService = raftService;
}
- private static NetworkMessage successResponse(CmgMessagesFactory
msgFactory) {
- log.info("CMG started successfully");
+ /**
+ * Starts the CMG Raft service using the provided node names as its peers.
+ */
+ private CompletableFuture<CmgRaftService>
startCmgRaftService(Collection<String> nodeNames) {
+ List<ClusterNode> nodes = resolveNodes(clusterService, nodeNames);
- return msgFactory.initCompleteMessage().build();
+ try {
+ return raftManager
+ .prepareRaftGroup(CMG_RAFT_GROUP_NAME, nodes, () -> {
+ raftStorage.start();
+
+ return new CmgRaftGroupListener(raftStorage);
+ })
+ .thenApply(service -> new CmgRaftService(service,
clusterService));
+ } catch (NodeStoppingException e) {
+ return CompletableFuture.failedFuture(e);
+ }
}
- private void broadcastClusterState(Collection<String> metaStorageNodes) {
- NetworkMessage clusterStateMsg = msgFactory.clusterStateMessage()
- .metastorageNodes(metaStorageNodes)
- .build();
+ private TopologyEventHandler cmgLeaderTopologyEventHandler(CmgRaftService
raftService) {
+ return new TopologyEventHandler() {
+ @Override
+ public void onAppeared(ClusterNode member) {
+ raftService.readClusterState()
+ .thenAccept(state -> {
+ if (state != null) {
+ sendClusterState(state, List.of(member));
+ } else if (log.isWarnEnabled()) {
+ log.warn("Cannot send the cluster state to a
newly added node {} because cluster state is empty", member);
Review Comment:
If a cluster is not initialized then the Raft service will not be started
and this topology handler will not be registered. As we discussed above, this
can happen if a leader failed to save the Cluster State.
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