Fix Watcher deadlock that can cause in-abilty to index documents. (#41418) (#41684)

This commit removes the usage of the `BulkProcessor` to write history documents
and delete triggered watches on a `EsRejectedExecutionException`. Since the
exception could be handled on the write thread, the write thread can be blocked
waiting on watcher threads (due to a synchronous method). This is problematic
since those watcher threads can be blocked waiting on write threads.

This commit also moves the handling of the exception to the generic threadpool
to avoid submitting write requests from the write thread pool.

fixes #41390
This commit is contained in:
Jake Landis 2019-04-30 16:13:24 -05:00 committed by GitHub
parent b3f4533e1c
commit 7ac3283509
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3 changed files with 218 additions and 22 deletions

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@ -16,8 +16,10 @@ import org.elasticsearch.ResourceNotFoundException;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.bulk.BulkItemResponse;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.support.PlainActionFuture;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.client.Client;
@ -33,19 +35,25 @@ import org.elasticsearch.common.util.concurrent.EsRejectedExecutionException;
import org.elasticsearch.common.util.concurrent.ThreadContext;
import org.elasticsearch.common.xcontent.ToXContent;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.common.xcontent.json.JsonXContent;
import org.elasticsearch.index.engine.DocumentMissingException;
import org.elasticsearch.index.engine.VersionConflictEngineException;
import org.elasticsearch.xpack.core.watcher.actions.ActionWrapper;
import org.elasticsearch.xpack.core.watcher.actions.ActionWrapperResult;
import org.elasticsearch.xpack.core.watcher.common.stats.Counters;
import org.elasticsearch.xpack.core.watcher.condition.Condition;
import org.elasticsearch.xpack.core.watcher.execution.ExecutionState;
import org.elasticsearch.xpack.core.watcher.execution.QueuedWatch;
import org.elasticsearch.xpack.core.watcher.execution.TriggeredWatchStoreField;
import org.elasticsearch.xpack.core.watcher.execution.WatchExecutionContext;
import org.elasticsearch.xpack.core.watcher.execution.WatchExecutionSnapshot;
import org.elasticsearch.xpack.core.watcher.execution.Wid;
import org.elasticsearch.xpack.core.watcher.history.HistoryStoreField;
import org.elasticsearch.xpack.core.watcher.history.WatchRecord;
import org.elasticsearch.xpack.core.watcher.input.Input;
import org.elasticsearch.xpack.core.watcher.support.xcontent.WatcherParams;
import org.elasticsearch.xpack.core.watcher.transform.Transform;
import org.elasticsearch.xpack.core.watcher.trigger.TriggerEvent;
import org.elasticsearch.xpack.core.watcher.watch.Watch;
@ -67,8 +75,10 @@ import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicReference;
@ -399,24 +409,70 @@ public class ExecutionService {
try {
executor.execute(new WatchExecutionTask(ctx, () -> execute(ctx)));
} catch (EsRejectedExecutionException e) {
String message = "failed to run triggered watch [" + triggeredWatch.id() + "] due to thread pool capacity";
WatchRecord record = ctx.abortBeforeExecution(ExecutionState.THREADPOOL_REJECTION, message);
try {
if (ctx.overrideRecordOnConflict()) {
historyStore.forcePut(record);
} else {
historyStore.put(record);
//Using the generic pool here since this can happen from a write thread and we don't want to block a write
//thread to kick off these additional write/delete requests.
//Intentionally not using the HistoryStore or TriggerWatchStore to avoid re-using the same synchronous
//BulkProcessor which can cause a deadlock see #41390
genericExecutor.execute(new WatchExecutionTask(ctx, () -> {
String message = "failed to run triggered watch [" + triggeredWatch.id() + "] due to thread pool capacity";
logger.warn(message);
WatchRecord record = ctx.abortBeforeExecution(ExecutionState.THREADPOOL_REJECTION, message);
try {
forcePutHistory(record);
} catch (Exception exc) {
logger.error((Supplier<?>) () ->
new ParameterizedMessage(
"Error storing watch history record for watch [{}] after thread pool rejection",
triggeredWatch.id()), exc);
}
} catch (Exception exc) {
logger.error((Supplier<?>) () ->
new ParameterizedMessage("Error storing watch history record for watch [{}] after thread pool rejection",
triggeredWatch.id()), exc);
}
triggeredWatchStore.delete(triggeredWatch.id());
deleteTrigger(triggeredWatch.id());
}));
}
}
/**
* Stores the specified watchRecord.
* Any existing watchRecord will be overwritten.
*/
private void forcePutHistory(WatchRecord watchRecord) {
String index = HistoryStoreField.getHistoryIndexNameForTime(watchRecord.triggerEvent().triggeredTime());
try {
try (XContentBuilder builder = XContentFactory.jsonBuilder();
ThreadContext.StoredContext ignore = client.threadPool().getThreadContext().stashWithOrigin(WATCHER_ORIGIN)) {
watchRecord.toXContent(builder, WatcherParams.HIDE_SECRETS);
IndexRequest request = new IndexRequest(index)
.id(watchRecord.id().value())
.source(builder)
.opType(IndexRequest.OpType.CREATE);
client.index(request).get(30, TimeUnit.SECONDS);
logger.debug("indexed watch history record [{}]", watchRecord.id().value());
} catch (VersionConflictEngineException vcee) {
watchRecord = new WatchRecord.MessageWatchRecord(watchRecord, ExecutionState.EXECUTED_MULTIPLE_TIMES,
"watch record [{ " + watchRecord.id() + " }] has been stored before, previous state [" + watchRecord.state() + "]");
try (XContentBuilder xContentBuilder = XContentFactory.jsonBuilder();
ThreadContext.StoredContext ignore = client.threadPool().getThreadContext().stashWithOrigin(WATCHER_ORIGIN)) {
IndexRequest request = new IndexRequest(index)
.id(watchRecord.id().value())
.source(xContentBuilder.value(watchRecord));
client.index(request).get(30, TimeUnit.SECONDS);
}
logger.debug("overwrote watch history record [{}]", watchRecord.id().value());
}
} catch (InterruptedException | ExecutionException | TimeoutException | IOException ioe) {
final WatchRecord wr = watchRecord;
logger.error((Supplier<?>) () -> new ParameterizedMessage("failed to persist watch record [{}]", wr), ioe);
}
}
private void deleteTrigger(Wid watcherId) {
DeleteRequest request = new DeleteRequest(TriggeredWatchStoreField.INDEX_NAME);
request.id(watcherId.value());
try (ThreadContext.StoredContext ignore = client.threadPool().getThreadContext().stashWithOrigin(WATCHER_ORIGIN)) {
client.delete(request).actionGet(30, TimeUnit.SECONDS);
}
logger.trace("successfully deleted triggered watch with id [{}]", watcherId);
}
WatchRecord executeInner(WatchExecutionContext ctx) {
ctx.start();
Watch watch = ctx.watch();

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@ -5,11 +5,13 @@
*/
package org.elasticsearch.xpack.watcher.execution;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.Version;
import org.elasticsearch.action.ActionFuture;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.support.PlainActionFuture;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.action.update.UpdateResponse;
@ -28,8 +30,11 @@ import org.elasticsearch.common.xcontent.ObjectPath;
import org.elasticsearch.common.xcontent.XContentFactory;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.Index;
import org.elasticsearch.index.IndexNotFoundException;
import org.elasticsearch.index.engine.VersionConflictEngineException;
import org.elasticsearch.index.get.GetResult;
import org.elasticsearch.index.shard.ShardId;
import org.elasticsearch.test.ESTestCase;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.xpack.core.security.authc.Authentication;
@ -48,6 +53,7 @@ import org.elasticsearch.xpack.core.watcher.condition.ExecutableCondition;
import org.elasticsearch.xpack.core.watcher.execution.ExecutionPhase;
import org.elasticsearch.xpack.core.watcher.execution.ExecutionState;
import org.elasticsearch.xpack.core.watcher.execution.QueuedWatch;
import org.elasticsearch.xpack.core.watcher.execution.TriggeredWatchStoreField;
import org.elasticsearch.xpack.core.watcher.execution.WatchExecutionContext;
import org.elasticsearch.xpack.core.watcher.execution.WatchExecutionSnapshot;
import org.elasticsearch.xpack.core.watcher.execution.Wid;
@ -91,6 +97,7 @@ import static java.util.Arrays.asList;
import static java.util.Collections.singletonMap;
import static org.elasticsearch.common.unit.TimeValue.timeValueSeconds;
import static org.elasticsearch.index.seqno.SequenceNumbers.UNASSIGNED_SEQ_NO;
import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.greaterThan;
import static org.hamcrest.Matchers.hasSize;
@ -844,11 +851,15 @@ public class ExecutionServiceTests extends ESTestCase {
when(getResponse.isExists()).thenReturn(true);
when(getResponse.getId()).thenReturn("foo");
mockGetWatchResponse(client, "foo", getResponse);
ActionFuture actionFuture = mock(ActionFuture.class);
when(actionFuture.get()).thenReturn("");
when(client.index(any())).thenReturn(actionFuture);
when(client.delete(any())).thenReturn(actionFuture);
when(parser.parseWithSecrets(eq("foo"), eq(true), any(), any(), any(), anyLong(), anyLong())).thenReturn(watch);
// execute needs to fail as well as storing the history
// execute needs to fail
doThrow(new EsRejectedExecutionException()).when(executor).execute(any());
doThrow(new ElasticsearchException("whatever")).when(historyStore).forcePut(any());
Wid wid = new Wid(watch.id(), ZonedDateTime.now(ZoneOffset.UTC));
@ -856,10 +867,58 @@ public class ExecutionServiceTests extends ESTestCase {
new ScheduleTriggerEvent(ZonedDateTime.now(ZoneOffset.UTC) ,ZonedDateTime.now(ZoneOffset.UTC)));
executionService.executeTriggeredWatches(Collections.singleton(triggeredWatch));
verify(triggeredWatchStore, times(1)).delete(wid);
ArgumentCaptor<WatchRecord> captor = ArgumentCaptor.forClass(WatchRecord.class);
verify(historyStore, times(1)).forcePut(captor.capture());
assertThat(captor.getValue().state(), is(ExecutionState.THREADPOOL_REJECTION));
ArgumentCaptor<DeleteRequest> deleteCaptor = ArgumentCaptor.forClass(DeleteRequest.class);
verify(client).delete(deleteCaptor.capture());
assertThat(deleteCaptor.getValue().index(), equalTo(TriggeredWatchStoreField.INDEX_NAME));
assertThat(deleteCaptor.getValue().id(), equalTo(wid.value()));
ArgumentCaptor<IndexRequest> watchHistoryCaptor = ArgumentCaptor.forClass(IndexRequest.class);
verify(client).index(watchHistoryCaptor.capture());
assertThat(watchHistoryCaptor.getValue().source().utf8ToString(), containsString(ExecutionState.THREADPOOL_REJECTION.toString()));
assertThat(watchHistoryCaptor.getValue().index(), containsString(".watcher-history"));
}
public void testForcePutHistoryOnExecutionRejection() throws Exception {
Watch watch = mock(Watch.class);
when(watch.id()).thenReturn("foo");
WatchStatus status = new WatchStatus(ZonedDateTime.now(ZoneOffset.UTC), Collections.emptyMap());
when(watch.status()).thenReturn(status);
GetResponse getResponse = mock(GetResponse.class);
when(getResponse.isExists()).thenReturn(true);
when(getResponse.getId()).thenReturn("foo");
mockGetWatchResponse(client, "foo", getResponse);
ActionFuture actionFuture = mock(ActionFuture.class);
when(actionFuture.get()).thenReturn("");
when(client.index(any()))
.thenThrow(new VersionConflictEngineException(
new ShardId(new Index("mockindex", "mockuuid"), 0), "id", "explaination"))
.thenReturn(actionFuture);
when(client.delete(any())).thenReturn(actionFuture);
when(parser.parseWithSecrets(eq("foo"), eq(true), any(), any(), any(), anyLong(), anyLong())).thenReturn(watch);
// execute needs to fail
doThrow(new EsRejectedExecutionException()).when(executor).execute(any());
Wid wid = new Wid(watch.id(), ZonedDateTime.now(ZoneOffset.UTC));
TriggeredWatch triggeredWatch = new TriggeredWatch(wid,
new ScheduleTriggerEvent(ZonedDateTime.now(ZoneOffset.UTC), ZonedDateTime.now(ZoneOffset.UTC)));
executionService.executeTriggeredWatches(Collections.singleton(triggeredWatch));
ArgumentCaptor<DeleteRequest> deleteCaptor = ArgumentCaptor.forClass(DeleteRequest.class);
verify(client).delete(deleteCaptor.capture());
assertThat(deleteCaptor.getValue().index(), equalTo(TriggeredWatchStoreField.INDEX_NAME));
assertThat(deleteCaptor.getValue().id(), equalTo(wid.value()));
ArgumentCaptor<IndexRequest> watchHistoryCaptor = ArgumentCaptor.forClass(IndexRequest.class);
verify(client, times(2)).index(watchHistoryCaptor.capture());
List<IndexRequest> indexRequests = watchHistoryCaptor.getAllValues();
assertThat(indexRequests.get(0).id(), equalTo(indexRequests.get(1).id()));
assertThat(indexRequests.get(0).source().utf8ToString(), containsString(ExecutionState.THREADPOOL_REJECTION.toString()));
assertThat(indexRequests.get(1).source().utf8ToString(), containsString(ExecutionState.EXECUTED_MULTIPLE_TIMES.toString()));
}
public void testThatTriggeredWatchDeletionHappensOnlyIfWatchExists() throws Exception {
@ -898,7 +957,7 @@ public class ExecutionServiceTests extends ESTestCase {
when(watch.status()).thenReturn(watchStatus);
executionService.execute(context);
verify(triggeredWatchStore, never()).delete(any());
verify(client, never()).delete(any());
}
public void testThatSingleWatchCannotBeExecutedConcurrently() throws Exception {

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@ -0,0 +1,81 @@
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License;
* you may not use this file except in compliance with the Elastic License.
*/
package org.elasticsearch.xpack.watcher.test.integration;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.license.LicenseService;
import org.elasticsearch.xpack.core.XPackSettings;
import org.elasticsearch.xpack.core.watcher.client.WatcherClient;
import org.elasticsearch.xpack.watcher.condition.CompareCondition;
import org.elasticsearch.xpack.watcher.support.search.WatcherSearchTemplateRequest;
import org.elasticsearch.xpack.watcher.test.AbstractWatcherIntegrationTestCase;
import org.elasticsearch.xpack.watcher.trigger.schedule.IntervalSchedule;
import java.util.concurrent.TimeUnit;
import static org.elasticsearch.index.query.QueryBuilders.termQuery;
import static org.elasticsearch.search.builder.SearchSourceBuilder.searchSource;
import static org.elasticsearch.xpack.watcher.actions.ActionBuilders.loggingAction;
import static org.elasticsearch.xpack.watcher.client.WatchSourceBuilders.watchBuilder;
import static org.elasticsearch.xpack.watcher.input.InputBuilders.searchInput;
import static org.elasticsearch.xpack.watcher.test.WatcherTestUtils.templateRequest;
import static org.elasticsearch.xpack.watcher.trigger.TriggerBuilders.schedule;
import static org.elasticsearch.xpack.watcher.trigger.schedule.Schedules.interval;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.greaterThanOrEqualTo;
public class RejectedExecutionTests extends AbstractWatcherIntegrationTestCase {
@Override
protected boolean timeWarped() {
//need to use the real scheduler
return false;
}
public void testHistoryAndTriggeredOnRejection() throws Exception {
WatcherClient watcherClient = watcherClient();
createIndex("idx");
client().prepareIndex("idx", "_doc").setSource("field", "a").get();
refresh();
WatcherSearchTemplateRequest request = templateRequest(searchSource().query(termQuery("field", "a")), "idx");
watcherClient.preparePutWatch(randomAlphaOfLength(5))
.setSource(watchBuilder()
.trigger(schedule(interval(1, IntervalSchedule.Interval.Unit.SECONDS)))
.input(searchInput(request))
.condition(new CompareCondition("ctx.payload.hits.total", CompareCondition.Op.EQ, 1L))
.addAction("_logger", loggingAction("_logging")
.setCategory("_category")))
.get();
assertBusy(() -> {
flushAndRefresh(".watcher-history-*");
SearchResponse searchResponse = client().prepareSearch(".watcher-history-*").get();
assertThat(searchResponse.getHits().getTotalHits().value, greaterThanOrEqualTo(2L));
}, 10, TimeUnit.SECONDS);
flushAndRefresh(".triggered_watches");
SearchResponse searchResponse = client().prepareSearch(".triggered_watches").get();
assertThat(searchResponse.getHits().getTotalHits().value, equalTo(0L));
}
@Override
protected Settings nodeSettings(int nodeOrdinal) {
return Settings.builder()
.put(super.nodeSettings(nodeOrdinal))
.put(XPackSettings.MONITORING_ENABLED.getKey(), false)
.put(XPackSettings.SECURITY_ENABLED.getKey(), false)
.put(LicenseService.SELF_GENERATED_LICENSE_TYPE.getKey(), "trial")
.put("thread_pool.write.size", 1)
.put("thread_pool.write.queue_size", 1)
.put("xpack.watcher.thread_pool.size", 1)
.put("xpack.watcher.thread_pool.queue_size", 0)
.build();
}
}