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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF 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.apache.solr.cloud;
import java.io.IOException;
import java.lang.invoke.MethodHandles;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import org.apache.http.client.HttpClient;
import org.apache.solr.client.solrj.SolrServerException;
import org.apache.solr.client.solrj.impl.HttpSolrClient;
import org.apache.solr.client.solrj.request.CoreAdminRequest.RequestRecovery;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.cloud.ZkCoreNodeProps;
import org.apache.solr.common.cloud.ZkNodeProps;
import org.apache.solr.common.params.CoreAdminParams.CoreAdminAction;
import org.apache.solr.common.params.ModifiableSolrParams;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.core.CoreContainer;
import org.apache.solr.core.CoreDescriptor;
import org.apache.solr.core.SolrCore;
import org.apache.solr.handler.component.ShardHandler;
import org.apache.solr.handler.component.ShardRequest;
import org.apache.solr.handler.component.ShardResponse;
import org.apache.solr.logging.MDCLoggingContext;
import org.apache.solr.update.PeerSync;
import org.apache.solr.update.UpdateShardHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.solr.common.params.CommonParams.DISTRIB;
public class SyncStrategy {
private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
private final boolean SKIP_AUTO_RECOVERY = Boolean.getBoolean("solrcloud.skip.autorecovery");
private final ShardHandler shardHandler;
private volatile boolean isClosed;
private final HttpClient client;
private final ExecutorService updateExecutor;
private final List<RecoveryRequest> recoveryRequests = new ArrayList<>();
private static class RecoveryRequest {
ZkNodeProps leaderProps;
String baseUrl;
String coreName;
}
public SyncStrategy(CoreContainer cc) {
UpdateShardHandler updateShardHandler = cc.getUpdateShardHandler();
client = updateShardHandler.getHttpClient();
shardHandler = cc.getShardHandlerFactory().getShardHandler();
updateExecutor = updateShardHandler.getUpdateExecutor();
}
private static class ShardCoreRequest extends ShardRequest {
String coreName;
public String baseUrl;
}
public PeerSync.PeerSyncResult sync(ZkController zkController, SolrCore core, ZkNodeProps leaderProps) {
return sync(zkController, core, leaderProps, false);
}
public PeerSync.PeerSyncResult sync(ZkController zkController, SolrCore core, ZkNodeProps leaderProps,
boolean peerSyncOnlyWithActive) {
if (SKIP_AUTO_RECOVERY) {
return PeerSync.PeerSyncResult.success();
}
MDCLoggingContext.setCore(core);
try {
if (isClosed) {
log.warn("Closed, skipping sync up.");
return PeerSync.PeerSyncResult.failure();
}
recoveryRequests.clear();
log.info("Sync replicas to " + ZkCoreNodeProps.getCoreUrl(leaderProps));
if (core.getUpdateHandler().getUpdateLog() == null) {
log.error("No UpdateLog found - cannot sync");
return PeerSync.PeerSyncResult.failure();
}
return syncReplicas(zkController, core, leaderProps, peerSyncOnlyWithActive);
} finally {
MDCLoggingContext.clear();
}
}
private PeerSync.PeerSyncResult syncReplicas(ZkController zkController, SolrCore core,
ZkNodeProps leaderProps, boolean peerSyncOnlyWithActive) {
boolean success = false;
PeerSync.PeerSyncResult result = null;
CloudDescriptor cloudDesc = core.getCoreDescriptor().getCloudDescriptor();
String collection = cloudDesc.getCollectionName();
String shardId = cloudDesc.getShardId();
if (isClosed) {
log.info("We have been closed, won't sync with replicas");
return PeerSync.PeerSyncResult.failure();
}
// first sync ourselves - we are the potential leader after all
try {
result = syncWithReplicas(zkController, core, leaderProps, collection,
shardId, peerSyncOnlyWithActive);
success = result.isSuccess();
} catch (Exception e) {
SolrException.log(log, "Sync Failed", e);
}
try {
if (isClosed) {
log.info("We have been closed, won't attempt to sync replicas back to leader");
return PeerSync.PeerSyncResult.failure();
}
if (success) {
log.info("Sync Success - now sync replicas to me");
syncToMe(zkController, collection, shardId, leaderProps, core.getCoreDescriptor(), core.getUpdateHandler().getUpdateLog().getNumRecordsToKeep());
} else {
log.info("Leader's attempt to sync with shard failed, moving to the next candidate");
// lets see who seems ahead...
}
} catch (Exception e) {
SolrException.log(log, "Sync Failed", e);
}
return result == null ? PeerSync.PeerSyncResult.failure() : result;
}
private PeerSync.PeerSyncResult syncWithReplicas(ZkController zkController, SolrCore core,
ZkNodeProps props, String collection, String shardId, boolean peerSyncOnlyWithActive) {
List<ZkCoreNodeProps> nodes = zkController.getZkStateReader()
.getReplicaProps(collection, shardId,core.getCoreDescriptor().getCloudDescriptor().getCoreNodeName());
if (nodes == null) {
// I have no replicas
return PeerSync.PeerSyncResult.success();
}
List<String> syncWith = new ArrayList<>(nodes.size());
for (ZkCoreNodeProps node : nodes) {
syncWith.add(node.getCoreUrl());
}
// if we can't reach a replica for sync, we still consider the overall sync a success
// TODO: as an assurance, we should still try and tell the sync nodes that we couldn't reach
// to recover once more?
// Fingerprinting here is off because the we currently rely on having at least one of the nodes return "true", and if replicas are out-of-sync
// we still need to pick one as leader. A followup sync from the replica to the new leader (with fingerprinting on) should then fail and
// initiate recovery-by-replication.
PeerSync peerSync = new PeerSync(core, syncWith, core.getUpdateHandler().getUpdateLog().getNumRecordsToKeep(), true, true, peerSyncOnlyWithActive, false);
return peerSync.sync();
}
private void syncToMe(ZkController zkController, String collection,
String shardId, ZkNodeProps leaderProps, CoreDescriptor cd,
int nUpdates) {
// sync everyone else
// TODO: we should do this in parallel at least
List<ZkCoreNodeProps> nodes = zkController
.getZkStateReader()
.getReplicaProps(collection, shardId,
cd.getCloudDescriptor().getCoreNodeName());
if (nodes == null) {
log.info(ZkCoreNodeProps.getCoreUrl(leaderProps) + " has no replicas");
return;
}
ZkCoreNodeProps zkLeader = new ZkCoreNodeProps(leaderProps);
for (ZkCoreNodeProps node : nodes) {
try {
log.info(ZkCoreNodeProps.getCoreUrl(leaderProps) + ": try and ask " + node.getCoreUrl() + " to sync");
requestSync(node.getBaseUrl(), node.getCoreUrl(), zkLeader.getCoreUrl(), node.getCoreName(), nUpdates);
} catch (Exception e) {
SolrException.log(log, "Error syncing replica to leader", e);
}
}
for(;;) {
ShardResponse srsp = shardHandler.takeCompletedOrError();
if (srsp == null) break;
boolean success = handleResponse(srsp);
if (srsp.getException() != null) {
SolrException.log(log, "Sync request error: " + srsp.getException());
}
if (!success) {
log.info(ZkCoreNodeProps.getCoreUrl(leaderProps) + ": Sync failed - we will ask replica (" + srsp.getShardAddress()
+ ") to recover.");
if (isClosed) {
log.info("We have been closed, don't request that a replica recover");
} else {
RecoveryRequest rr = new RecoveryRequest();
rr.leaderProps = leaderProps;
rr.baseUrl = ((ShardCoreRequest) srsp.getShardRequest()).baseUrl;
rr.coreName = ((ShardCoreRequest) srsp.getShardRequest()).coreName;
recoveryRequests.add(rr);
}
} else {
log.info(ZkCoreNodeProps.getCoreUrl(leaderProps) + ": " + " sync completed with " + srsp.getShardAddress());
}
}
}
private boolean handleResponse(ShardResponse srsp) {
NamedList<Object> response = srsp.getSolrResponse().getResponse();
// TODO: why does this return null sometimes?
if (response == null) {
return false;
}
Boolean success = (Boolean) response.get("sync");
if (success == null) {
success = false;
}
return success;
}
private void requestSync(String baseUrl, String replica, String leaderUrl, String coreName, int nUpdates) {
ShardCoreRequest sreq = new ShardCoreRequest();
sreq.coreName = coreName;
sreq.baseUrl = baseUrl;
sreq.purpose = 1;
sreq.shards = new String[]{replica};
sreq.actualShards = sreq.shards;
sreq.params = new ModifiableSolrParams();
sreq.params.set("qt","/get");
sreq.params.set(DISTRIB,false);
sreq.params.set("getVersions",Integer.toString(nUpdates));
sreq.params.set("sync",leaderUrl);
shardHandler.submit(sreq, replica, sreq.params);
}
public void close() {
this.isClosed = true;
}
public void requestRecoveries() {
for (RecoveryRequest rr : recoveryRequests) {
try {
requestRecovery(rr.leaderProps, rr.baseUrl, rr.coreName);
} catch (SolrServerException | IOException e) {
log.error("Problem requesting that a replica recover", e);
}
}
}
private void requestRecovery(final ZkNodeProps leaderProps, final String baseUrl, final String coreName) throws SolrServerException, IOException {
Thread thread = new Thread() {
{
setDaemon(true);
}
@Override
public void run() {
RequestRecovery recoverRequestCmd = new RequestRecovery();
recoverRequestCmd.setAction(CoreAdminAction.REQUESTRECOVERY);
recoverRequestCmd.setCoreName(coreName);
try (HttpSolrClient client = new HttpSolrClient.Builder(baseUrl).withHttpClient(SyncStrategy.this.client).build()) {
client.setConnectionTimeout(30000);
client.setSoTimeout(120000);
client.request(recoverRequestCmd);
} catch (Throwable t) {
SolrException.log(log, ZkCoreNodeProps.getCoreUrl(leaderProps) + ": Could not tell a replica to recover", t);
if (t instanceof Error) {
throw (Error) t;
}
}
}
};
updateExecutor.execute(thread);
}
public static ModifiableSolrParams params(String... params) {
ModifiableSolrParams msp = new ModifiableSolrParams();
for (int i = 0; i < params.length; i += 2) {
msp.add(params[i], params[i + 1]);
}
return msp;
}
}