-
Notifications
You must be signed in to change notification settings - Fork 25.6k
Master Node Disconnect #134213
New issue
Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.
By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.
Already on GitHub? Sign in to your account
Merged
joshua-adams-1
merged 6 commits into
elastic:main
from
joshua-adams-1:master-node-disconnect
Oct 9, 2025
Merged
Master Node Disconnect #134213
Changes from 2 commits
Commits
Show all changes
6 commits
Select commit
Hold shift + click to select a range
cfa5845
Master Node Disconnect
joshua-adams-1 3487710
[CI] Auto commit changes from spotless
233cb32
Merge branch 'main' into master-node-disconnect
joshua-adams-1 8770a25
Merge branch 'master-node-disconnect' of https://github.com/joshua-ad…
joshua-adams-1 a11759b
Merge branch 'main' into master-node-disconnect
joshua-adams-1 6881f0f
Uncomments out assertion
joshua-adams-1 File filter
Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
There are no files selected for viewing
258 changes: 258 additions & 0 deletions
258
...er/src/internalClusterTest/java/org/elasticsearch/cluster/coordination/NodeJoiningIT.java
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,258 @@ | ||
| /* | ||
| * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one | ||
| * or more contributor license agreements. Licensed under the "Elastic License | ||
| * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side | ||
| * Public License v 1"; you may not use this file except in compliance with, at | ||
| * your election, the "Elastic License 2.0", the "GNU Affero General Public | ||
| * License v3.0 only", or the "Server Side Public License, v 1". | ||
| */ | ||
|
|
||
| package org.elasticsearch.cluster.coordination; | ||
|
|
||
| import org.apache.logging.log4j.Level; | ||
| import org.elasticsearch.ElasticsearchException; | ||
| import org.elasticsearch.cluster.ClusterState; | ||
| import org.elasticsearch.cluster.node.DiscoveryNode; | ||
| import org.elasticsearch.cluster.node.DiscoveryNodes; | ||
| import org.elasticsearch.cluster.service.ClusterApplierService; | ||
| import org.elasticsearch.cluster.service.ClusterService; | ||
| import org.elasticsearch.cluster.service.MasterService; | ||
| import org.elasticsearch.common.settings.Settings; | ||
| import org.elasticsearch.common.util.CollectionUtils; | ||
| import org.elasticsearch.plugins.Plugin; | ||
| import org.elasticsearch.test.ClusterServiceUtils; | ||
| import org.elasticsearch.test.ESIntegTestCase; | ||
| import org.elasticsearch.test.MockLog; | ||
| import org.elasticsearch.test.junit.annotations.TestLogging; | ||
| import org.elasticsearch.test.transport.MockTransportService; | ||
| import org.elasticsearch.transport.Transport; | ||
| import org.elasticsearch.transport.TransportService; | ||
|
|
||
| import java.util.Collection; | ||
| import java.util.List; | ||
|
|
||
| @ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0, numClientNodes = 0) | ||
| public class NodeJoiningIT extends ESIntegTestCase { | ||
|
|
||
| @Override | ||
| protected Collection<Class<? extends Plugin>> nodePlugins() { | ||
| return CollectionUtils.appendToCopyNoNullElements(super.nodePlugins(), MockTransportService.TestPlugin.class); | ||
| } | ||
|
|
||
| @Override | ||
| protected Settings nodeSettings(int nodeOrdinal, Settings otherSettings) { | ||
| return Settings.builder() | ||
| .put(super.nodeSettings(nodeOrdinal, otherSettings)) | ||
| // detect leader failover quickly | ||
| .put(LeaderChecker.LEADER_CHECK_RETRY_COUNT_SETTING.getKey(), 1) | ||
| .put(LeaderChecker.LEADER_CHECK_INTERVAL_SETTING.getKey(), "100ms") | ||
| .build(); | ||
| } | ||
|
|
||
| public void testNodeJoinsCluster() { | ||
| internalCluster().startNodes(3); | ||
| String masterNodeName = internalCluster().getMasterName(); | ||
| int numberOfNodesOriginallyInCluster = internalCluster().clusterService(masterNodeName).state().getNodes().size(); | ||
| int numberOfMasterNodesOriginallyInCluster = internalCluster().clusterService(masterNodeName) | ||
| .state() | ||
| .nodes() | ||
| .getMasterNodes() | ||
| .size(); | ||
| List<String> namesOfDataNodesInOriginalCluster = getListOfDataNodeNamesFromCluster(masterNodeName); | ||
|
|
||
| // Attempt to add new node | ||
| String newNodeName = internalCluster().startDataOnlyNode(); | ||
| ensureStableCluster(4); | ||
|
|
||
| // Assert the new data node was added | ||
| ClusterState state = internalCluster().clusterService(masterNodeName).state(); | ||
| assertEquals(numberOfNodesOriginallyInCluster + 1, state.nodes().getSize()); | ||
| assertEquals(namesOfDataNodesInOriginalCluster.size() + 1, state.nodes().getDataNodes().size()); | ||
| assertEquals(numberOfMasterNodesOriginallyInCluster, state.nodes().getMasterNodes().size()); | ||
|
|
||
| List<String> namesOfDataNodesInNewCluster = getListOfDataNodeNamesFromCluster(masterNodeName); | ||
| assertTrue(namesOfDataNodesInNewCluster.contains(newNodeName)); | ||
| for (String nodeName : namesOfDataNodesInOriginalCluster) { | ||
| assertTrue(namesOfDataNodesInNewCluster.contains(nodeName)); | ||
| } | ||
| } | ||
|
|
||
| @TestLogging(reason = "test includes assertions about logging", value = "org.elasticsearch.cluster.coordination.NodeJoinExecutor:INFO") | ||
| public void testNodeTriesToJoinClusterAndThenDifferentMasterIsElected() { | ||
| List<String> nodeNames = internalCluster().startNodes(3); | ||
| ensureStableCluster(3); | ||
| String originalMasterNodeName = internalCluster().getMasterName(); | ||
| int numberOfNodesOriginallyInCluster = internalCluster().clusterService(originalMasterNodeName).state().getNodes().size(); | ||
| // Determine upfront who we want the next master to be | ||
| final var newMasterNodeName = randomValueOtherThan(originalMasterNodeName, () -> randomFrom(nodeNames)); | ||
|
|
||
| // Ensure the logging is as expected | ||
| try (var mockLog = MockLog.capture(NodeJoinExecutor.class)) { | ||
|
|
||
| // Sets MockTransportService behaviour | ||
| for (final var transportService : internalCluster().getInstances(TransportService.class)) { | ||
| final var mockTransportService = asInstanceOf(MockTransportService.class, transportService); | ||
|
|
||
| if (mockTransportService.getLocalNode().getName().equals(newMasterNodeName) == false) { | ||
| List<String> listOfActionsToBlock = List.of( | ||
| // This forces the current master node to fail | ||
| PublicationTransportHandler.PUBLISH_STATE_ACTION_NAME, | ||
| // This disables pre-voting on all nodes except the new master, forcing it to win the election | ||
| StatefulPreVoteCollector.REQUEST_PRE_VOTE_ACTION_NAME | ||
| ); | ||
| blockActionNameOnMockTransportService(mockTransportService, listOfActionsToBlock); | ||
| } | ||
| } | ||
|
|
||
| // We do not expect to see a WARN log about a node disconnecting (#ES-11449) | ||
| addJoiningNodeDisconnectedWarnLogFalseExpectation(mockLog); | ||
|
|
||
| // We haven't changed master nodes yet | ||
| assertEquals(originalMasterNodeName, internalCluster().getMasterName()); | ||
|
|
||
| // Sends a node join request to the original master node. This will fail, and cause a master failover | ||
| // startDataOnlyNode waits for the new node to be added, and this can only occur after a re-election | ||
| String newNodeName = internalCluster().startDataOnlyNode(); | ||
| assertNotEquals(originalMasterNodeName, internalCluster().getMasterName()); | ||
| logger.info("New master is elected"); | ||
|
|
||
| // Assert all nodes have accepted N into their cluster state | ||
| assertNewNodeIsInAllClusterStates(newNodeName); | ||
|
|
||
| mockLog.assertAllExpectationsMatched(); | ||
|
|
||
| // Assert the new data node was added | ||
| DiscoveryNodes discoveryNodes = internalCluster().clusterService().state().nodes(); | ||
| assertEquals(numberOfNodesOriginallyInCluster + 1, discoveryNodes.getSize()); | ||
| assertTrue(getListOfDataNodeNamesFromCluster(newMasterNodeName).contains(newNodeName)); | ||
| } | ||
| } | ||
|
|
||
| /* | ||
| In this scenario, node N attempts to join a cluster, there is an election and the original master is re-elected. | ||
| Node N should join the cluster, but it should not be disconnected (#ES-11449) | ||
| */ | ||
| @TestLogging(reason = "test includes assertions about logging", value = "org.elasticsearch.cluster.coordination:INFO") | ||
| public void testNodeTriesToJoinClusterAndThenSameMasterIsElected() { | ||
| internalCluster().startNodes(3); | ||
| ensureStableCluster(3); | ||
| String masterNodeName = internalCluster().getMasterName(); | ||
|
|
||
| long originalTerm = getTerm(masterNodeName); | ||
| int numberOfNodesOriginallyInCluster = internalCluster().clusterService(masterNodeName).state().getNodes().size(); | ||
|
|
||
| try (var mockLog = MockLog.capture(NodeJoinExecutor.class, MasterService.class, ClusterApplierService.class)) { | ||
| for (String nodeName : internalCluster().getNodeNames()) { | ||
| final var mockTransportService = MockTransportService.getInstance(nodeName); | ||
|
|
||
| if (nodeName.equals(masterNodeName)) { | ||
| // This makes the master fail, forcing a re-election | ||
| blockActionNameOnMockTransportService( | ||
| mockTransportService, | ||
| List.of(PublicationTransportHandler.PUBLISH_STATE_ACTION_NAME) | ||
| ); | ||
|
|
||
| // Wait until the master has stepped down before removing the publishing ban | ||
| // This allows the master to be re-elected | ||
| ClusterServiceUtils.addTemporaryStateListener(internalCluster().clusterService(masterNodeName), clusterState -> { | ||
| DiscoveryNode currentMasterNode = clusterState.nodes().getMasterNode(); | ||
| boolean hasMasterSteppedDown = currentMasterNode == null | ||
| || currentMasterNode.getName().equals(masterNodeName) == false; | ||
| if (hasMasterSteppedDown) { | ||
| logger.info("Master publishing ban removed"); | ||
| mockTransportService.addSendBehavior(Transport.Connection::sendRequest); | ||
| } | ||
| return hasMasterSteppedDown; | ||
| }); | ||
|
|
||
| } else { | ||
| // This disables pre-voting on all nodes except the master, forcing it to win the election | ||
| blockActionNameOnMockTransportService( | ||
| mockTransportService, | ||
| List.of(StatefulPreVoteCollector.REQUEST_PRE_VOTE_ACTION_NAME) | ||
| ); | ||
| } | ||
| } | ||
|
|
||
| // We expect the node join request to fail with a FailedToCommitClusterStateException | ||
| mockLog.addExpectation( | ||
| new MockLog.SeenEventExpectation( | ||
| "failed to commit cluster state", | ||
| MasterService.class.getCanonicalName(), | ||
| Level.WARN, | ||
| "failed to commit cluster state" | ||
| ) | ||
| ); | ||
|
|
||
| /* | ||
| We expect the cluster to reuse the connection to N and not disconnect it | ||
| Therefore, this WARN log should not be thrown (#ES-11449) | ||
| */ | ||
| addJoiningNodeDisconnectedWarnLogFalseExpectation(mockLog); | ||
|
|
||
| // Before we add the new node, assert we haven't changed master nodes yet | ||
| assertEquals(masterNodeName, internalCluster().getMasterName()); | ||
|
|
||
| // Sends a node join request to the original master node. This will fail, and cause a master failover | ||
| logger.info("Sending node join request"); | ||
| String newNodeName = internalCluster().startDataOnlyNode(); | ||
|
|
||
| // Assert the master was re-elected | ||
| assertEquals(masterNodeName, internalCluster().getMasterName()); | ||
| assertTrue(originalTerm < getTerm(masterNodeName)); | ||
|
|
||
| // Assert all nodes have accepted N into their cluster state | ||
| assertNewNodeIsInAllClusterStates(newNodeName); | ||
|
|
||
| // If the WARN log was thrown, then the connection to N was disconnected so fail the test | ||
| mockLog.assertAllExpectationsMatched(); | ||
|
|
||
| // Assert the new data node was added | ||
| DiscoveryNodes discoveryNodes = internalCluster().clusterService().state().nodes(); | ||
| assertEquals(numberOfNodesOriginallyInCluster + 1, discoveryNodes.getSize()); | ||
| assertTrue(getListOfDataNodeNamesFromCluster(masterNodeName).contains(newNodeName)); | ||
| } | ||
| } | ||
|
|
||
| private long getTerm(String masterNodeName) { | ||
| return internalCluster().clusterService(masterNodeName).state().coordinationMetadata().term(); | ||
| } | ||
|
|
||
| private void assertNewNodeIsInAllClusterStates(String newNodeName) { | ||
| for (ClusterService clusterService : internalCluster().getInstances(ClusterService.class)) { | ||
| assertTrue(clusterService.state().nodes().getAllNodes().stream().map(DiscoveryNode::getName).toList().contains(newNodeName)); | ||
| } | ||
| } | ||
|
|
||
| private List<String> getListOfDataNodeNamesFromCluster(String nodeName) { | ||
| return internalCluster().clusterService(nodeName) | ||
| .state() | ||
| .getNodes() | ||
| .getDataNodes() | ||
| .values() | ||
| .stream() | ||
| .map(DiscoveryNode::getName) | ||
| .toList(); | ||
| } | ||
|
|
||
| private void addJoiningNodeDisconnectedWarnLogFalseExpectation(MockLog mockLog) { | ||
| mockLog.addExpectation( | ||
| new MockLog.UnseenEventExpectation( | ||
| "warn message with troubleshooting link", | ||
| "org.elasticsearch.cluster.coordination.NodeJoinExecutor", | ||
| Level.WARN, | ||
| "*" | ||
| ) | ||
| ); | ||
| } | ||
|
|
||
| private void blockActionNameOnMockTransportService(MockTransportService mockTransportService, List<String> actionNamesToBlock) { | ||
| mockTransportService.addSendBehavior((connection, requestId, action, request, options) -> { | ||
| if (actionNamesToBlock.contains(action)) { | ||
| throw new ElasticsearchException("[{}] for [{}] denied", action, connection.getNode()); | ||
| } else { | ||
| connection.sendRequest(requestId, action, request, options); | ||
| } | ||
| }); | ||
| } | ||
| } |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
This comment is currently a lie, and we definitely shouldn't have any commented-out code like this. At the very least we should delete these lines.
But the issue here is that this indicates that we're misusing
FailedToCommitClusterStateExceptionand throwing it from places where the cluster state update has not even been published, which means we can be certain its effects won't appear in some future state. In those cases we don't need to delay the completion of the join listener. It's kind of ok, but would you investigate whether we can reasonably fix these to use a different exception (e.g.NotMasterException) and tighten up the meaning ofFailedToCommitClusterStateExceptionso that it can only happen if we're unsure of the outcome?There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
If so, that should be a separate PR which lands ahead of this one.
Uh oh!
There was an error while loading. Please reload this page.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Apologies! I clearly commented out the code to run the tests and then forgot to delete them (insert face palm here)
To confirm, this is to investigate where we're throwing the
FailedToCommitClusterStateExceptionand ensuring they're only thrown from appropriate places? I can do thatThere was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Yep