From 23f00e367673bec2637deb52d95e9c6bee3d4963 Mon Sep 17 00:00:00 2001 From: David Turner Date: Fri, 1 Feb 2019 08:10:49 +0000 Subject: [PATCH] Relax fault detector in some disruption tests (#38101) Today we use `AbstractDisruptionTestCase` to test the behaviour of things like master elections in the presence of cluster disruptions. These tests have rather enthusiastic fault detection settings, detecting a fault if a single ping fails, with a one-second timeout. Furthermore there are some tests that assert the identity of the master remains unchanged during some disruption, and these assertions fail rather often thanks to the overly sensitive fault detector. However in a number of these tests the fault detector need not be this sensitive. This commit moves some such tests into their own test suite and uses more sensible fault-detection settings to avoid the kind of master instability that is causing CI failures. Closes #37699 --- .../discovery/MasterDisruptionIT.java | 71 -------- .../discovery/StableMasterDisruptionIT.java | 170 ++++++++++++++++++ 2 files changed, 170 insertions(+), 71 deletions(-) create mode 100644 server/src/test/java/org/elasticsearch/discovery/StableMasterDisruptionIT.java diff --git a/server/src/test/java/org/elasticsearch/discovery/MasterDisruptionIT.java b/server/src/test/java/org/elasticsearch/discovery/MasterDisruptionIT.java index 718904eecb5..fc9450e9826 100644 --- a/server/src/test/java/org/elasticsearch/discovery/MasterDisruptionIT.java +++ b/server/src/test/java/org/elasticsearch/discovery/MasterDisruptionIT.java @@ -30,7 +30,6 @@ import org.elasticsearch.cluster.metadata.IndexMetaData; import org.elasticsearch.cluster.node.DiscoveryNode; import org.elasticsearch.cluster.service.ClusterService; import org.elasticsearch.common.Priority; -import org.elasticsearch.common.Strings; import org.elasticsearch.common.collect.Tuple; import org.elasticsearch.common.settings.Settings; import org.elasticsearch.common.unit.TimeValue; @@ -71,76 +70,6 @@ import static org.hamcrest.Matchers.nullValue; @ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0, transportClientRatio = 0) public class MasterDisruptionIT extends AbstractDisruptionTestCase { - /** - * Test that no split brain occurs under partial network partition. See https://github.com/elastic/elasticsearch/issues/2488 - */ - public void testFailWithMinimumMasterNodesConfigured() throws Exception { - List nodes = startCluster(3); - - // Figure out what is the elected master node - final String masterNode = internalCluster().getMasterName(); - logger.info("---> legit elected master node={}", masterNode); - - // Pick a node that isn't the elected master. - Set nonMasters = new HashSet<>(nodes); - nonMasters.remove(masterNode); - final String unluckyNode = randomFrom(nonMasters.toArray(Strings.EMPTY_ARRAY)); - - - // Simulate a network issue between the unlucky node and elected master node in both directions. - - NetworkDisruption networkDisconnect = new NetworkDisruption( - new NetworkDisruption.TwoPartitions(masterNode, unluckyNode), - new NetworkDisruption.NetworkDisconnect()); - setDisruptionScheme(networkDisconnect); - networkDisconnect.startDisrupting(); - - // Wait until elected master has removed that the unlucky node... - ensureStableCluster(2, masterNode); - - // The unlucky node must report *no* master node, since it can't connect to master and in fact it should - // continuously ping until network failures have been resolved. However - // It may a take a bit before the node detects it has been cut off from the elected master - assertNoMaster(unluckyNode); - - networkDisconnect.stopDisrupting(); - - // Wait until the master node sees all 3 nodes again. - ensureStableCluster(3); - - // The elected master shouldn't have changed, since the unlucky node never could have elected himself as - // master since m_m_n of 2 could never be satisfied. - assertMaster(masterNode, nodes); - } - - /** - * Verify that nodes fault detection works after master (re) election - */ - public void testNodesFDAfterMasterReelection() throws Exception { - startCluster(4); - - logger.info("--> stopping current master"); - internalCluster().stopCurrentMasterNode(); - - ensureStableCluster(3); - - String master = internalCluster().getMasterName(); - String nonMaster = null; - for (String node : internalCluster().getNodeNames()) { - if (!node.equals(master)) { - nonMaster = node; - } - } - - logger.info("--> isolating [{}]", nonMaster); - NetworkDisruption.TwoPartitions partitions = isolateNode(nonMaster); - NetworkDisruption networkDisruption = addRandomDisruptionType(partitions); - networkDisruption.startDisrupting(); - - logger.info("--> waiting for master to remove it"); - ensureStableCluster(2, master); - } - /** * Tests that emulates a frozen elected master node that unfreezes and pushes his cluster state to other nodes * that already are following another elected master node. These nodes should reject this cluster state and prevent diff --git a/server/src/test/java/org/elasticsearch/discovery/StableMasterDisruptionIT.java b/server/src/test/java/org/elasticsearch/discovery/StableMasterDisruptionIT.java new file mode 100644 index 00000000000..b5177b1ce3e --- /dev/null +++ b/server/src/test/java/org/elasticsearch/discovery/StableMasterDisruptionIT.java @@ -0,0 +1,170 @@ +/* + * Licensed to Elasticsearch under one or more contributor + * license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright + * ownership. Elasticsearch licenses this file to you under + * the Apache License, Version 2.0 (the "License"); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package org.elasticsearch.discovery; + +import org.elasticsearch.action.admin.cluster.state.ClusterStateRequest; +import org.elasticsearch.cluster.coordination.FollowersChecker; +import org.elasticsearch.cluster.coordination.LeaderChecker; +import org.elasticsearch.common.Strings; +import org.elasticsearch.common.settings.Settings; +import org.elasticsearch.common.util.set.Sets; +import org.elasticsearch.plugins.Plugin; +import org.elasticsearch.test.ESIntegTestCase; +import org.elasticsearch.test.disruption.NetworkDisruption; +import org.elasticsearch.test.disruption.NetworkDisruption.NetworkDisconnect; +import org.elasticsearch.test.disruption.NetworkDisruption.NetworkUnresponsive; +import org.elasticsearch.test.junit.annotations.TestLogging; +import org.elasticsearch.test.transport.MockTransportService.TestPlugin; + +import java.util.Arrays; +import java.util.Collection; +import java.util.Collections; +import java.util.HashSet; +import java.util.List; +import java.util.Set; +import java.util.stream.Collectors; +import java.util.stream.Stream; + +import static java.util.Collections.singleton; +import static org.hamcrest.Matchers.equalTo; + +/** + * Tests relating to the loss of the master, but which work with the default fault detection settings which are rather lenient and will + * not detect a master failure too quickly. + */ +@TestLogging("_root:DEBUG,org.elasticsearch.cluster.service:TRACE") +@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0, transportClientRatio = 0) +public class StableMasterDisruptionIT extends ESIntegTestCase { + + @Override + protected Collection> nodePlugins() { + return Collections.singletonList(TestPlugin.class); + } + + /** + * Test that no split brain occurs under partial network partition. See https://github.com/elastic/elasticsearch/issues/2488 + */ + public void testFailWithMinimumMasterNodesConfigured() throws Exception { + List nodes = internalCluster().startNodes(3); + ensureStableCluster(3); + + // Figure out what is the elected master node + final String masterNode = internalCluster().getMasterName(); + logger.info("---> legit elected master node={}", masterNode); + + // Pick a node that isn't the elected master. + Set nonMasters = new HashSet<>(nodes); + nonMasters.remove(masterNode); + final String unluckyNode = randomFrom(nonMasters.toArray(Strings.EMPTY_ARRAY)); + + // Simulate a network issue between the unlucky node and elected master node in both directions. + + NetworkDisruption networkDisconnect = new NetworkDisruption( + new NetworkDisruption.TwoPartitions(masterNode, unluckyNode), + new NetworkDisruption.NetworkDisconnect()); + setDisruptionScheme(networkDisconnect); + networkDisconnect.startDisrupting(); + + // Wait until elected master has removed that the unlucky node... + ensureStableCluster(2, masterNode); + + // The unlucky node must report *no* master node, since it can't connect to master and in fact it should + // continuously ping until network failures have been resolved. However + // It may a take a bit before the node detects it has been cut off from the elected master + assertBusy(() -> assertNull(client(unluckyNode).admin().cluster().state( + new ClusterStateRequest().local(true)).get().getState().nodes().getMasterNode())); + + networkDisconnect.stopDisrupting(); + + // Wait until the master node sees all 3 nodes again. + ensureStableCluster(3); + + // The elected master shouldn't have changed, since the unlucky node never could have elected itself as master + assertThat(internalCluster().getMasterName(), equalTo(masterNode)); + } + + /** + * Verify that nodes fault detection works after master (re) election + */ + public void testFollowerCheckerDetectsUnresponsiveNodeAfterMasterReelection() throws Exception { + internalCluster().startNodes(4, + Settings.builder() + .put(LeaderChecker.LEADER_CHECK_TIMEOUT_SETTING.getKey(), "1s") + .put(LeaderChecker.LEADER_CHECK_RETRY_COUNT_SETTING.getKey(), "10") + .put(FollowersChecker.FOLLOWER_CHECK_TIMEOUT_SETTING.getKey(), "1s") + .put(FollowersChecker.FOLLOWER_CHECK_RETRY_COUNT_SETTING.getKey(), 1).build()); + ensureStableCluster(4); + + logger.info("--> stopping current master"); + internalCluster().stopCurrentMasterNode(); + + ensureStableCluster(3); + + final String master = internalCluster().getMasterName(); + final List nonMasters = Arrays.stream(internalCluster().getNodeNames()).filter(n -> master.equals(n) == false) + .collect(Collectors.toList()); + final String isolatedNode = randomFrom(nonMasters); + final String otherNode = nonMasters.get(nonMasters.get(0).equals(isolatedNode) ? 1 : 0); + + logger.info("--> isolating [{}]", isolatedNode); + + final NetworkDisruption networkDisruption = new NetworkDisruption(new NetworkDisruption.TwoPartitions( + singleton(isolatedNode), Sets.newHashSet(master, otherNode)), new NetworkUnresponsive()); + setDisruptionScheme(networkDisruption); + networkDisruption.startDisrupting(); + + logger.info("--> waiting for master to remove it"); + ensureStableCluster(2, master); + + networkDisruption.stopDisrupting(); + ensureStableCluster(3); + } + + /** + * Verify that nodes fault detection works after master (re) election + */ + public void testFollowerCheckerDetectsDisconnectedNodeAfterMasterReelection() throws Exception { + internalCluster().startNodes(4); + ensureStableCluster(4); + + logger.info("--> stopping current master"); + internalCluster().stopCurrentMasterNode(); + + ensureStableCluster(3); + + final String master = internalCluster().getMasterName(); + final List nonMasters = Arrays.stream(internalCluster().getNodeNames()).filter(n -> master.equals(n) == false) + .collect(Collectors.toList()); + final String isolatedNode = randomFrom(nonMasters); + final String otherNode = nonMasters.get(nonMasters.get(0).equals(isolatedNode) ? 1 : 0); + + logger.info("--> isolating [{}]", isolatedNode); + + final NetworkDisruption networkDisruption = new NetworkDisruption(new NetworkDisruption.TwoPartitions( + singleton(isolatedNode), Stream.of(master, otherNode).collect(Collectors.toSet())), new NetworkDisconnect()); + setDisruptionScheme(networkDisruption); + networkDisruption.startDisrupting(); + + logger.info("--> waiting for master to remove it"); + ensureStableCluster(2, master); + + networkDisruption.stopDisrupting(); + ensureStableCluster(3); + } +}