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Fix trimUnsafeCommits for indices created before 6.2 (#57187)
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If an upgraded node is restarted multiple times without flushing a new
index commit, then we will wrongly exclude all commits from the starting
commits. This bug is reproducible with these minimal steps: (1) create
an empty index on 6.1.4 with translog retention disabled, (2) upgrade
the cluster to 7.7.0, (3) restart the upgraded the cluster. The problem
is that with the new translog policy can trim translog without having a
new index commit, while the existing commit still refers to the previous
translog generation.

Closes #57091
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dnhatn committed May 27, 2020
1 parent 14c732e commit 190d0dc
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Showing 10 changed files with 352 additions and 27 deletions.
Expand Up @@ -348,6 +348,11 @@ public void goToNextVersion() {
writeUnicastHostsFiles();
}

public void fullRestart() {
stop(false);
start();
}

public void nextNodeToNextVersion() {
if (nodeIndex + 1 > nodes.size()) {
throw new TestClustersException("Ran out of nodes to take to the next version");
Expand Down
Expand Up @@ -653,24 +653,6 @@ static String toStr(Response response) throws IOException {
return EntityUtils.toString(response.getEntity());
}

static void assertNoFailures(Map<?, ?> response) {
int failed = (int) XContentMapValues.extractValue("_shards.failed", response);
assertEquals(0, failed);
}

void assertTotalHits(int expectedTotalHits, Map<?, ?> response) {
int actualTotalHits = extractTotalHits(response);
assertEquals(response.toString(), expectedTotalHits, actualTotalHits);
}

int extractTotalHits(Map<?, ?> response) {
if (isRunningAgainstOldCluster() && getOldClusterVersion().before(Version.V_7_0_0)) {
return (Integer) XContentMapValues.extractValue("hits.total", response);
} else {
return (Integer) XContentMapValues.extractValue("hits.total.value", response);
}
}

/**
* Tests that a single document survives. Super basic smoke test.
*/
Expand Down Expand Up @@ -708,6 +690,12 @@ public void testEmptyShard() throws IOException {
// before timing out
.put(INDEX_DELAYED_NODE_LEFT_TIMEOUT_SETTING.getKey(), "100ms")
.put(SETTING_ALLOCATION_MAX_RETRY.getKey(), "0"); // fail faster
if (getOldClusterVersion().onOrAfter(Version.V_6_5_0)) {
settings.put(IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey(), randomBoolean());
}
if (randomBoolean()) {
settings.put(IndexSettings.INDEX_TRANSLOG_RETENTION_SIZE_SETTING.getKey(), "-1");
}
createIndex(index, settings.build());
}
ensureGreen(index);
Expand Down Expand Up @@ -1429,4 +1417,43 @@ public void testTurnOffTranslogRetentionAfterUpgraded() throws Exception {
ensurePeerRecoveryRetentionLeasesRenewedAndSynced(index);
}
}

public void testRecoveryWithTranslogRetentionDisabled() throws Exception {
if (isRunningAgainstOldCluster()) {
final Settings.Builder settings = Settings.builder()
.put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
.put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1);
if (getOldClusterVersion().onOrAfter(Version.V_6_5_0)) {
settings.put(IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey(), randomBoolean());
}
if (randomBoolean()) {
settings.put(IndexSettings.INDEX_TRANSLOG_RETENTION_SIZE_SETTING.getKey(), "-1");
}
if (randomBoolean()) {
settings.put(IndexSettings.INDEX_TRANSLOG_GENERATION_THRESHOLD_SIZE_SETTING.getKey(), "1kb");
}
createIndex(index, settings.build());
ensureGreen(index);
int numDocs = randomIntBetween(0, 100);
for (int i = 0; i < numDocs; i++) {
indexDocument(Integer.toString(i));
if (rarely()) {
flush(index, randomBoolean());
}
}
client().performRequest(new Request("POST", "/" + index + "/_refresh"));
if (randomBoolean()) {
ensurePeerRecoveryRetentionLeasesRenewedAndSynced(index);
}
if (randomBoolean()) {
flush(index, randomBoolean());
} else if (randomBoolean()) {
performSyncedFlush(index);
}
saveInfoDocument("doc_count", Integer.toString(numDocs));
}
ensureGreen(index);
final int numDocs = Integer.parseInt(loadInfoDocument("doc_count"));
assertTotalHits(numDocs, entityAsMap(client().performRequest(new Request("GET", "/" + index + "/_search"))));
}
}
101 changes: 101 additions & 0 deletions qa/translog-policy/build.gradle
@@ -0,0 +1,101 @@
/*
* 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.
*/


import org.elasticsearch.gradle.Version
import org.elasticsearch.gradle.info.BuildParams
import org.elasticsearch.gradle.testclusters.RestTestRunnerTask
import org.elasticsearch.gradle.testclusters.TestDistribution

apply plugin: 'elasticsearch.testclusters'
apply plugin: 'elasticsearch.standalone-test'
apply from : "$rootDir/gradle/bwc-test.gradle"

for (Version bwcVersion : BuildParams.bwcVersions.indexCompatible) {
String baseName = "v${bwcVersion}"

testClusters {
"${baseName}" {
versions = [bwcVersion.toString(), project.version]
numberOfNodes = 2
setting 'http.content_type.required', 'true'
}
}

tasks.register("${baseName}#Step1OldClusterTest", RestTestRunnerTask) {
useCluster testClusters."${baseName}"
mustRunAfter(precommit)
systemProperty 'tests.test_step', 'step1'
systemProperty 'tests.is_old_cluster', 'true'
}

tasks.register("${baseName}#Step2OldClusterTest", RestTestRunnerTask) {
useCluster testClusters."${baseName}"
dependsOn "${baseName}#Step1OldClusterTest"
doFirst {
testClusters."${baseName}".fullRestart()
}
systemProperty 'tests.test_step', 'step2'
systemProperty 'tests.is_old_cluster', 'true'
}

tasks.register("${baseName}#Step3NewClusterTest", RestTestRunnerTask) {
useCluster testClusters."${baseName}"
dependsOn "${baseName}#Step2OldClusterTest"
doFirst {
testClusters."${baseName}".goToNextVersion()
}
systemProperty 'tests.test_step', 'step3'
systemProperty 'tests.is_old_cluster', 'false'
}

tasks.register("${baseName}#Step4NewClusterTest", RestTestRunnerTask) {
useCluster testClusters."${baseName}"
dependsOn "${baseName}#Step3NewClusterTest"
doFirst {
testClusters."${baseName}".fullRestart()
}
systemProperty 'tests.test_step', 'step4'
systemProperty 'tests.is_old_cluster', 'false'
}

String oldVersion = bwcVersion.toString().minus("-SNAPSHOT")
tasks.matching { it.name.startsWith(baseName) && it.name.endsWith("ClusterTest") }.configureEach {
it.systemProperty 'tests.old_cluster_version', oldVersion
it.nonInputProperties.systemProperty('tests.rest.cluster', "${-> testClusters."${baseName}".allHttpSocketURI.join(",")}")
it.nonInputProperties.systemProperty('tests.clustername', "${-> testClusters."${baseName}".getName()}")
}

tasks.register(bwcTaskName(bwcVersion)) {
dependsOn tasks.named("${baseName}#Step4NewClusterTest")
}
}

configurations {
testArtifacts.extendsFrom testRuntime
}

task testJar(type: Jar) {
appendix 'test'
from sourceSets.test.output
}

artifacts {
testArtifacts testJar
}
@@ -0,0 +1,147 @@
/*
* 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.upgrades;

import org.elasticsearch.Version;
import org.elasticsearch.client.Request;
import org.elasticsearch.cluster.metadata.IndexMetadata;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.xcontent.json.JsonXContent;
import org.elasticsearch.index.IndexSettings;
import org.junit.Before;

import java.io.IOException;
import java.util.Locale;

/**
* Ensures that we correctly trim unsafe commits when migrating from a translog generation to the sequence number based policy.
* See https://github.com/elastic/elasticsearch/issues/57091
*/
public class TranslogPolicyIT extends AbstractFullClusterRestartTestCase {

private enum TestStep {
STEP1_OLD_CLUSTER("step1"),
STEP2_OLD_CLUSTER("step2"),
STEP3_NEW_CLUSTER("step3"),
STEP4_NEW_CLUSTER("step4");

private final String name;

TestStep(String name) {
this.name = name;
}

@Override
public String toString() {
return name;
}

public static TestStep parse(String value) {
switch (value) {
case "step1":
return STEP1_OLD_CLUSTER;
case "step2":
return STEP2_OLD_CLUSTER;
case "step3":
return STEP3_NEW_CLUSTER;
case "step4":
return STEP4_NEW_CLUSTER;
default:
throw new AssertionError("unknown test step: " + value);
}
}
}

protected static final TestStep TEST_STEP = TestStep.parse(System.getProperty("tests.test_step"));

private String index;
private String type;

@Before
public void setIndex() {
index = getTestName().toLowerCase(Locale.ROOT);
}

@Before
public void setType() {
type = getOldClusterVersion().before(Version.V_6_7_0) ? "doc" : "_doc";
}

public void testEmptyIndex() throws Exception {
if (TEST_STEP == TestStep.STEP1_OLD_CLUSTER) {
final Settings.Builder settings = Settings.builder()
.put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
.put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, between(0, 1));
if (getOldClusterVersion().onOrAfter(Version.V_6_5_0)) {
settings.put(IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey(), randomBoolean());
}
if (randomBoolean()) {
settings.put(IndexSettings.INDEX_TRANSLOG_RETENTION_SIZE_SETTING.getKey(), "-1");
}
createIndex(index, settings.build());
}
ensureGreen(index);
assertTotalHits(0, entityAsMap(client().performRequest(new Request("GET", "/" + index + "/_search"))));
}

public void testRecoverReplica() throws Exception {
int numDocs = 100;
if (TEST_STEP == TestStep.STEP1_OLD_CLUSTER) {
final Settings.Builder settings = Settings.builder()
.put(IndexMetadata.SETTING_NUMBER_OF_SHARDS, 1)
.put(IndexMetadata.SETTING_NUMBER_OF_REPLICAS, 1);
if (getOldClusterVersion().onOrAfter(Version.V_6_5_0)) {
settings.put(IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey(), randomBoolean());
}
if (randomBoolean()) {
settings.put(IndexSettings.INDEX_TRANSLOG_RETENTION_SIZE_SETTING.getKey(), "-1");
}
if (randomBoolean()) {
settings.put(IndexSettings.INDEX_TRANSLOG_GENERATION_THRESHOLD_SIZE_SETTING.getKey(), "1kb");
}
createIndex(index, settings.build());
ensureGreen(index);
for (int i = 0; i < numDocs; i++) {
indexDocument(Integer.toString(i));
if (rarely()) {
flush(index, randomBoolean());
}
}
client().performRequest(new Request("POST", "/" + index + "/_refresh"));
if (randomBoolean()) {
ensurePeerRecoveryRetentionLeasesRenewedAndSynced(index);
}
if (randomBoolean()) {
flush(index, randomBoolean());
} else if (randomBoolean()) {
performSyncedFlush(index);
}
}
ensureGreen(index);
assertTotalHits(100, entityAsMap(client().performRequest(new Request("GET", "/" + index + "/_search"))));
}

private void indexDocument(String id) throws IOException {
final Request indexRequest = new Request("POST", "/" + index + "/" + type + "/" + id);
indexRequest.setJsonEntity(Strings.toString(JsonXContent.contentBuilder().startObject().field("f", "v").endObject()));
assertOK(client().performRequest(indexRequest));
}
}
Expand Up @@ -179,7 +179,7 @@ synchronized boolean releaseCommit(final IndexCommit snapshotCommit) {
*/
public static IndexCommit findSafeCommitPoint(List<IndexCommit> commits, long globalCheckpoint) throws IOException {
if (commits.isEmpty()) {
throw new IllegalArgumentException("Commit list must not empty");
throw new IllegalArgumentException("Commit list must not be empty");
}
final int keptPosition = indexOfKeptCommits(commits, globalCheckpoint);
return commits.get(keptPosition);
Expand Down
Expand Up @@ -1423,14 +1423,16 @@ public long recoverLocallyUpToGlobalCheckpoint() {
logger.debug("skip local recovery as failed to find the safe commit", e);
return UNASSIGNED_SEQ_NO;
}
if (safeCommit.isPresent() == false) {
logger.trace("skip local recovery as no safe commit found");
return UNASSIGNED_SEQ_NO;
}
assert safeCommit.get().localCheckpoint <= globalCheckpoint : safeCommit.get().localCheckpoint + " > " + globalCheckpoint;
try {
maybeCheckIndex(); // check index here and won't do it again if ops-based recovery occurs
recoveryState.setStage(RecoveryState.Stage.TRANSLOG);
if (safeCommit.isPresent() == false) {
assert globalCheckpoint == UNASSIGNED_SEQ_NO || indexSettings.getIndexVersionCreated().before(Version.V_6_2_0) :
"global checkpoint [" + globalCheckpoint + "] [ created version [" + indexSettings.getIndexVersionCreated() + "]";
logger.trace("skip local recovery as no safe commit found");
return UNASSIGNED_SEQ_NO;
}
assert safeCommit.get().localCheckpoint <= globalCheckpoint : safeCommit.get().localCheckpoint + " > " + globalCheckpoint;
if (safeCommit.get().localCheckpoint == globalCheckpoint) {
logger.trace("skip local recovery as the safe commit is up to date; safe commit {} global checkpoint {}",
safeCommit.get(), globalCheckpoint);
Expand Down
8 changes: 6 additions & 2 deletions server/src/main/java/org/elasticsearch/index/store/Store.java
Expand Up @@ -1525,8 +1525,12 @@ public void trimUnsafeCommits(final long lastSyncedGlobalCheckpoint, final long
recoverableCommits.add(commit);
}
}
assert recoverableCommits.isEmpty() == false : "No commit point with translog found; " +
"commits [" + existingCommits + "], minRetainedTranslogGen [" + minRetainedTranslogGen + "]";
// We could reach here if the node is restarted multiple times after upgraded without flushing a new index commit.
// In this case, we can safely consider all commits as the starting commit because we have trimmed the unsafe
// commits in the first restart.
if (recoverableCommits.isEmpty()) {
recoverableCommits.addAll(existingCommits);
}
startingIndexCommit = CombinedDeletionPolicy.findSafeCommitPoint(recoverableCommits, lastSyncedGlobalCheckpoint);
} else {
// TODO: Asserts the starting commit is a safe commit once peer-recovery sets global checkpoint.
Expand Down

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