Files
gerrit/java/com/google/gerrit/server/index/change/ReindexAfterRefUpdate.java
Patrick Hiesel d03143571d Replace reindexAfterRefUpdate setting with indexMergeable
Gerrit can index a boolean field called 'mergeable' that determines
if a change can be merged into the target ref. This bit can change
whenever the target ref advances. Gerrit therefore has logic to
reindex all open changes when the target ref advances.

Depending on the number of open changes, the frequency of updates of
the target ref and the size of the repo, this can be a very expensive
operation. For large installations, 'reindexAfterRefUpdate' was added
as a setting back in 2015 (I88ae7f4ad) to turn off automatic
reindexing.

This setting however, leads to inconsistent behavior: Gerrit stops
updating documents when the target ref advances, so the 'mergeable'
bit in the indexed document can be stale. For large repos, it is
most likely stale. Users can still query for 'is:mergeable' though and
Gerrit happily serves that stale bit in any query response.

It is worth noting, that all of this does not affect the UI as that
sends a separate, asynchronous request to compute mergeablitly when
needed and does not rely on the index.

This commit cleans this behavior up by replacing reindexAfterRefUpdate
with indexMergeable. After this commit, there are two modes of operation:
1) Gerrit indexes 'mergable' and keeps it up to date when the target ref
   advances. Gerrit allows queries for 'is:mergeable'.
2) Gerrit does not index 'mergeable' at all. Gerrit does not allow
   queries for 'is:mergeable'.

This way, users always get a consistent and correct result.

Change-Id: I053af1b99616920db7f0dda8f8ec770e8683df5c
2019-11-18 16:06:31 -08:00

167 lines
5.9 KiB
Java

// Copyright (C) 2014 The Android Open Source Project
//
// Licensed 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 com.google.gerrit.server.index.change;
import static com.google.common.util.concurrent.MoreExecutors.directExecutor;
import static com.google.gerrit.server.query.change.ChangeData.asChanges;
import com.google.common.flogger.FluentLogger;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.gerrit.entities.Account;
import com.google.gerrit.entities.BranchNameKey;
import com.google.gerrit.entities.Change;
import com.google.gerrit.entities.Project;
import com.google.gerrit.entities.RefNames;
import com.google.gerrit.extensions.events.GitReferenceUpdatedListener;
import com.google.gerrit.server.account.AccountCache;
import com.google.gerrit.server.config.AllUsersName;
import com.google.gerrit.server.config.GerritServerConfig;
import com.google.gerrit.server.git.QueueProvider.QueueType;
import com.google.gerrit.server.index.IndexExecutor;
import com.google.gerrit.server.index.account.AccountIndexer;
import com.google.gerrit.server.query.change.InternalChangeQuery;
import com.google.gerrit.server.util.ManualRequestContext;
import com.google.gerrit.server.util.OneOffRequestContext;
import com.google.gerrit.server.util.RequestContext;
import com.google.inject.Inject;
import com.google.inject.Provider;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.Future;
import org.eclipse.jgit.lib.Config;
public class ReindexAfterRefUpdate implements GitReferenceUpdatedListener {
private static final FluentLogger logger = FluentLogger.forEnclosingClass();
private final OneOffRequestContext requestContext;
private final Provider<InternalChangeQuery> queryProvider;
private final ChangeIndexer.Factory indexerFactory;
private final ChangeIndexCollection indexes;
private final AllUsersName allUsersName;
private final AccountCache accountCache;
private final Provider<AccountIndexer> indexer;
private final ListeningExecutorService executor;
private final boolean enabled;
@Inject
ReindexAfterRefUpdate(
@GerritServerConfig Config cfg,
OneOffRequestContext requestContext,
Provider<InternalChangeQuery> queryProvider,
ChangeIndexer.Factory indexerFactory,
ChangeIndexCollection indexes,
AllUsersName allUsersName,
AccountCache accountCache,
Provider<AccountIndexer> indexer,
@IndexExecutor(QueueType.BATCH) ListeningExecutorService executor) {
this.requestContext = requestContext;
this.queryProvider = queryProvider;
this.indexerFactory = indexerFactory;
this.indexes = indexes;
this.allUsersName = allUsersName;
this.accountCache = accountCache;
this.indexer = indexer;
this.executor = executor;
this.enabled = cfg.getBoolean("index", "change", "indexMergeable", true);
}
@Override
public void onGitReferenceUpdated(Event event) {
if (allUsersName.get().equals(event.getProjectName())) {
Account.Id accountId = Account.Id.fromRef(event.getRefName());
if (accountId != null && !event.getRefName().startsWith(RefNames.REFS_STARRED_CHANGES)) {
accountCache.evict(accountId);
indexer.get().index(accountId);
}
}
if (!enabled
|| event.getRefName().startsWith(RefNames.REFS_CHANGES)
|| event.getRefName().startsWith(RefNames.REFS_DRAFT_COMMENTS)
|| event.getRefName().startsWith(RefNames.REFS_USERS)) {
return;
}
Futures.addCallback(
executor.submit(new GetChanges(event)),
new FutureCallback<List<Change>>() {
@Override
public void onSuccess(List<Change> changes) {
for (Change c : changes) {
@SuppressWarnings("unused")
Future<?> possiblyIgnoredError =
indexerFactory.create(executor, indexes).indexAsync(c.getProject(), c.getId());
}
}
@Override
public void onFailure(Throwable ignored) {
// Logged by {@link GetChanges#call()}.
}
},
directExecutor());
}
private abstract class Task<V> implements Callable<V> {
protected Event event;
protected Task(Event event) {
this.event = event;
}
@Override
public final V call() throws Exception {
try (ManualRequestContext ctx = requestContext.open()) {
return impl(ctx);
} catch (Exception e) {
logger.atSevere().withCause(e).log("Failed to reindex changes after %s", event);
throw e;
}
}
protected abstract V impl(RequestContext ctx) throws Exception;
protected abstract void remove();
}
private class GetChanges extends Task<List<Change>> {
private GetChanges(Event event) {
super(event);
}
@Override
protected List<Change> impl(RequestContext ctx) {
String ref = event.getRefName();
Project.NameKey project = Project.nameKey(event.getProjectName());
if (ref.equals(RefNames.REFS_CONFIG)) {
return asChanges(queryProvider.get().byProjectOpen(project));
}
return asChanges(queryProvider.get().byBranchNew(BranchNameKey.create(project, ref)));
}
@Override
public String toString() {
return "Get changes to reindex caused by "
+ event.getRefName()
+ " update of project "
+ event.getProjectName();
}
@Override
protected void remove() {}
}
}