/*
* 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 static org.apache.solr.common.cloud.ZkStateReader.COLLECTION_PROP;
import static org.apache.solr.common.cloud.ZkStateReader.CORE_NAME_PROP;
import static org.apache.solr.common.params.CommonAdminParams.ASYNC;
import static org.apache.solr.common.params.CommonParams.NAME;
import java.lang.invoke.MethodHandles;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.SolrException.ErrorCode;
import org.apache.solr.common.cloud.ClusterState;
import org.apache.solr.common.cloud.DocCollection;
import org.apache.solr.common.cloud.Replica;
import org.apache.solr.common.cloud.Slice;
import org.apache.solr.common.cloud.SolrZkClient;
import org.apache.solr.common.cloud.ZkNodeProps;
import org.apache.solr.common.cloud.Replica.State;
import org.apache.solr.common.params.CoreAdminParams;
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.snapshots.CollectionSnapshotMetaData;
import org.apache.solr.core.snapshots.CollectionSnapshotMetaData.CoreSnapshotMetaData;
import org.apache.solr.core.snapshots.CollectionSnapshotMetaData.SnapshotStatus;
import org.apache.solr.core.snapshots.SolrSnapshotManager;
import org.apache.solr.handler.component.ShardHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* This class implements the functionality of creating a collection level snapshot.
*/
public class CreateSnapshotCmd implements OverseerCollectionMessageHandler.Cmd {
private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
private final OverseerCollectionMessageHandler ocmh;
public CreateSnapshotCmd (OverseerCollectionMessageHandler ocmh) {
this.ocmh = ocmh;
}
@Override
public void call(ClusterState state, ZkNodeProps message, NamedList results) throws Exception {
String collectionName = message.getStr(COLLECTION_PROP);
String commitName = message.getStr(CoreAdminParams.COMMIT_NAME);
String asyncId = message.getStr(ASYNC);
SolrZkClient zkClient = this.ocmh.overseer.getZkController().getZkClient();
Date creationDate = new Date();
if(SolrSnapshotManager.snapshotExists(zkClient, collectionName, commitName)) {
throw new SolrException(ErrorCode.BAD_REQUEST, "Snapshot with name " + commitName
+ " already exists for collection " + collectionName);
}
log.info("Creating a snapshot for collection={} with commitName={}", collectionName, commitName);
// Create a node in ZK to store the collection level snapshot meta-data.
SolrSnapshotManager.createCollectionLevelSnapshot(zkClient, collectionName, new CollectionSnapshotMetaData(commitName));
log.info("Created a ZK path to store snapshot information for collection={} with commitName={}", collectionName, commitName);
Map<String, String> requestMap = new HashMap<>();
NamedList shardRequestResults = new NamedList();
Map<String, Slice> shardByCoreName = new HashMap<>();
ShardHandler shardHandler = ocmh.shardHandlerFactory.getShardHandler();
for (Slice slice : ocmh.zkStateReader.getClusterState().getCollection(collectionName).getSlices()) {
for (Replica replica : slice.getReplicas()) {
if (replica.getState() != State.ACTIVE) {
log.info("Replica {} is not active. Hence not sending the createsnapshot request", replica.getCoreName());
continue; // Since replica is not active - no point sending a request.
}
String coreName = replica.getStr(CORE_NAME_PROP);
ModifiableSolrParams params = new ModifiableSolrParams();
params.set(CoreAdminParams.ACTION, CoreAdminAction.CREATESNAPSHOT.toString());
params.set(NAME, slice.getName());
params.set(CORE_NAME_PROP, coreName);
params.set(CoreAdminParams.COMMIT_NAME, commitName);
ocmh.sendShardRequest(replica.getNodeName(), params, shardHandler, asyncId, requestMap);
log.debug("Sent createsnapshot request to core={} with commitName={}", coreName, commitName);
shardByCoreName.put(coreName, slice);
}
}
// At this point we want to make sure that at-least one replica for every shard
// is able to create the snapshot. If that is not the case, then we fail the request.
// This is to take care of the situation where e.g. entire shard is unavailable.
Set<String> failedShards = new HashSet<>();
ocmh.processResponses(shardRequestResults, shardHandler, false, null, asyncId, requestMap);
NamedList success = (NamedList) shardRequestResults.get("success");
List<CoreSnapshotMetaData> replicas = new ArrayList<>();
if (success != null) {
for ( int i = 0 ; i < success.size() ; i++) {
NamedList resp = (NamedList)success.getVal(i);
// Check if this core is the leader for the shard. The idea here is that during the backup
// operation we preferably use the snapshot of the "leader" replica since it is most likely
// to have latest state.
String coreName = (String)resp.get(CoreAdminParams.CORE);
Slice slice = shardByCoreName.remove(coreName);
boolean leader = (slice.getLeader() != null && slice.getLeader().getCoreName().equals(coreName));
resp.add(SolrSnapshotManager.SHARD_ID, slice.getName());
resp.add(SolrSnapshotManager.LEADER, leader);
CoreSnapshotMetaData c = new CoreSnapshotMetaData(resp);
replicas.add(c);
log.info("Snapshot with commitName {} is created successfully for core {}", commitName, c.getCoreName());
}
}
if (!shardByCoreName.isEmpty()) { // One or more failures.
log.warn("Unable to create a snapshot with name {} for following cores {}", commitName, shardByCoreName.keySet());
// Count number of failures per shard.
Map<String, Integer> failuresByShardId = new HashMap<>();
for (Map.Entry<String,Slice> entry : shardByCoreName.entrySet()) {
int f = 0;
if (failuresByShardId.get(entry.getValue().getName()) != null) {
f = failuresByShardId.get(entry.getValue().getName());
}
failuresByShardId.put(entry.getValue().getName(), f + 1);
}
// Now that we know number of failures per shard, we can figure out
// if at-least one replica per shard was able to create a snapshot or not.
DocCollection collectionStatus = ocmh.zkStateReader.getClusterState().getCollection(collectionName);
for (Map.Entry<String,Integer> entry : failuresByShardId.entrySet()) {
int replicaCount = collectionStatus.getSlice(entry.getKey()).getReplicas().size();
if (replicaCount <= entry.getValue()) {
failedShards.add(entry.getKey());
}
}
}
if (failedShards.isEmpty()) { // No failures.
CollectionSnapshotMetaData meta = new CollectionSnapshotMetaData(commitName, SnapshotStatus.Successful, creationDate, replicas);
SolrSnapshotManager.updateCollectionLevelSnapshot(zkClient, collectionName, meta);
log.info("Saved following snapshot information for collection={} with commitName={} in Zookeeper : {}", collectionName,
commitName, meta.toNamedList());
} else {
log.warn("Failed to create a snapshot for collection {} with commitName = {}. Snapshot could not be captured for following shards {}",
collectionName, commitName, failedShards);
// Update the ZK meta-data to include only cores with the snapshot. This will enable users to figure out
// which cores have the named snapshot.
CollectionSnapshotMetaData meta = new CollectionSnapshotMetaData(commitName, SnapshotStatus.Failed, creationDate, replicas);
SolrSnapshotManager.updateCollectionLevelSnapshot(zkClient, collectionName, meta);
log.info("Saved following snapshot information for collection={} with commitName={} in Zookeeper : {}", collectionName,
commitName, meta.toNamedList());
throw new SolrException(ErrorCode.SERVER_ERROR, "Failed to create snapshot on shards " + failedShards);
}
}
}