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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.
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package org.apache.solr.cloud;
import java.lang.invoke.MethodHandles;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.solr.client.solrj.request.CoreAdminRequest;
import org.apache.solr.cloud.OverseerCollectionMessageHandler.Cmd;
import org.apache.solr.cloud.overseer.OverseerAction;
import org.apache.solr.cloud.rule.ReplicaAssigner;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.cloud.ClusterState;
import org.apache.solr.common.cloud.CompositeIdRouter;
import org.apache.solr.common.cloud.DocCollection;
import org.apache.solr.common.cloud.DocRouter;
import org.apache.solr.common.cloud.PlainIdRouter;
import org.apache.solr.common.cloud.Replica;
import org.apache.solr.common.cloud.Slice;
import org.apache.solr.common.cloud.ZkNodeProps;
import org.apache.solr.common.cloud.ZkStateReader;
import org.apache.solr.common.params.CoreAdminParams;
import org.apache.solr.common.params.ModifiableSolrParams;
import org.apache.solr.common.util.NamedList;
import org.apache.solr.common.util.Utils;
import org.apache.solr.handler.component.ShardHandler;
import org.apache.solr.util.TestInjection;
import org.apache.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.solr.cloud.OverseerCollectionMessageHandler.COLL_PROP_PREFIX;
import static org.apache.solr.cloud.OverseerCollectionMessageHandler.SKIP_CREATE_REPLICA_IN_CLUSTER_STATE;
import static org.apache.solr.common.cloud.ZkStateReader.COLLECTION_PROP;
import static org.apache.solr.common.cloud.ZkStateReader.SHARD_ID_PROP;
import static org.apache.solr.common.params.CollectionParams.CollectionAction.ADDREPLICA;
import static org.apache.solr.common.params.CollectionParams.CollectionAction.CREATESHARD;
import static org.apache.solr.common.params.CollectionParams.CollectionAction.DELETESHARD;
import static org.apache.solr.common.params.CommonAdminParams.ASYNC;
public class SplitShardCmd implements Cmd {
private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
private final OverseerCollectionMessageHandler ocmh;
public SplitShardCmd(OverseerCollectionMessageHandler ocmh) {
this.ocmh = ocmh;
}
@Override
public void call(ClusterState state, ZkNodeProps message, NamedList results) throws Exception {
split(state, message, results);
}
public boolean split(ClusterState clusterState, ZkNodeProps message, NamedList results) throws Exception {
String collectionName = message.getStr("collection");
String slice = message.getStr(ZkStateReader.SHARD_ID_PROP);
log.info("Split shard invoked");
ZkStateReader zkStateReader = ocmh.zkStateReader;
zkStateReader.forceUpdateCollection(collectionName);
String splitKey = message.getStr("split.key");
ShardHandler shardHandler = ocmh.shardHandlerFactory.getShardHandler();
DocCollection collection = clusterState.getCollection(collectionName);
DocRouter router = collection.getRouter() != null ? collection.getRouter() : DocRouter.DEFAULT;
Slice parentSlice;
if (slice == null) {
if (router instanceof CompositeIdRouter) {
Collection<Slice> searchSlices = router.getSearchSlicesSingle(splitKey, new ModifiableSolrParams(), collection);
if (searchSlices.isEmpty()) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Unable to find an active shard for split.key: " + splitKey);
}
if (searchSlices.size() > 1) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
"Splitting a split.key: " + splitKey + " which spans multiple shards is not supported");
}
parentSlice = searchSlices.iterator().next();
slice = parentSlice.getName();
log.info("Split by route.key: {}, parent shard is: {} ", splitKey, slice);
} else {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
"Split by route key can only be used with CompositeIdRouter or subclass. Found router: "
+ router.getClass().getName());
}
} else {
parentSlice = collection.getSlice(slice);
}
if (parentSlice == null) {
// no chance of the collection being null because ClusterState#getCollection(String) would have thrown
// an exception already
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "No shard with the specified name exists: " + slice);
}
// find the leader for the shard
Replica parentShardLeader = null;
try {
parentShardLeader = zkStateReader.getLeaderRetry(collectionName, slice, 10000);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
}
// let's record the ephemeralOwner of the parent leader node
Stat leaderZnodeStat = zkStateReader.getZkClient().exists(ZkStateReader.LIVE_NODES_ZKNODE + "/" + parentShardLeader.getNodeName(), null, true);
if (leaderZnodeStat == null) {
// we just got to know the leader but its live node is gone already!
throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "The shard leader node: " + parentShardLeader.getNodeName() + " is not live anymore!");
}
DocRouter.Range range = parentSlice.getRange();
if (range == null) {
range = new PlainIdRouter().fullRange();
}
List<DocRouter.Range> subRanges = null;
String rangesStr = message.getStr(CoreAdminParams.RANGES);
if (rangesStr != null) {
String[] ranges = rangesStr.split(",");
if (ranges.length == 0 || ranges.length == 1) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "There must be at least two ranges specified to split a shard");
} else {
subRanges = new ArrayList<>(ranges.length);
for (int i = 0; i < ranges.length; i++) {
String r = ranges[i];
try {
subRanges.add(DocRouter.DEFAULT.fromString(r));
} catch (Exception e) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Exception in parsing hexadecimal hash range: " + r, e);
}
if (!subRanges.get(i).isSubsetOf(range)) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
"Specified hash range: " + r + " is not a subset of parent shard's range: " + range.toString());
}
}
List<DocRouter.Range> temp = new ArrayList<>(subRanges); // copy to preserve original order
Collections.sort(temp);
if (!range.equals(new DocRouter.Range(temp.get(0).min, temp.get(temp.size() - 1).max))) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
"Specified hash ranges: " + rangesStr + " do not cover the entire range of parent shard: " + range);
}
for (int i = 1; i < temp.size(); i++) {
if (temp.get(i - 1).max + 1 != temp.get(i).min) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "Specified hash ranges: " + rangesStr
+ " either overlap with each other or " + "do not cover the entire range of parent shard: " + range);
}
}
}
} else if (splitKey != null) {
if (router instanceof CompositeIdRouter) {
CompositeIdRouter compositeIdRouter = (CompositeIdRouter) router;
subRanges = compositeIdRouter.partitionRangeByKey(splitKey, range);
if (subRanges.size() == 1) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "The split.key: " + splitKey
+ " has a hash range that is exactly equal to hash range of shard: " + slice);
}
for (DocRouter.Range subRange : subRanges) {
if (subRange.min == subRange.max) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, "The split.key: " + splitKey + " must be a compositeId");
}
}
log.info("Partitioning parent shard " + slice + " range: " + parentSlice.getRange() + " yields: " + subRanges);
rangesStr = "";
for (int i = 0; i < subRanges.size(); i++) {
DocRouter.Range subRange = subRanges.get(i);
rangesStr += subRange.toString();
if (i < subRanges.size() - 1) rangesStr += ',';
}
}
} else {
// todo: fixed to two partitions?
subRanges = router.partitionRange(2, range);
}
try {
List<String> subSlices = new ArrayList<>(subRanges.size());
List<String> subShardNames = new ArrayList<>(subRanges.size());
String nodeName = parentShardLeader.getNodeName();
for (int i = 0; i < subRanges.size(); i++) {
String subSlice = slice + "_" + i;
subSlices.add(subSlice);
String subShardName = collectionName + "_" + subSlice + "_replica1";
subShardNames.add(subShardName);
}
boolean oldShardsDeleted = false;
for (String subSlice : subSlices) {
Slice oSlice = collection.getSlice(subSlice);
if (oSlice != null) {
final Slice.State state = oSlice.getState();
if (state == Slice.State.ACTIVE) {
throw new SolrException(SolrException.ErrorCode.BAD_REQUEST,
"Sub-shard: " + subSlice + " exists in active state. Aborting split shard.");
} else if (state == Slice.State.CONSTRUCTION || state == Slice.State.RECOVERY) {
// delete the shards
log.info("Sub-shard: {} already exists therefore requesting its deletion", subSlice);
Map<String, Object> propMap = new HashMap<>();
propMap.put(Overseer.QUEUE_OPERATION, "deleteshard");
propMap.put(COLLECTION_PROP, collectionName);
propMap.put(SHARD_ID_PROP, subSlice);
ZkNodeProps m = new ZkNodeProps(propMap);
try {
ocmh.commandMap.get(DELETESHARD).call(clusterState, m, new NamedList());
} catch (Exception e) {
throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Unable to delete already existing sub shard: " + subSlice,
e);
}
oldShardsDeleted = true;
}
}
}
if (oldShardsDeleted) {
// refresh the locally cached cluster state
// we know we have the latest because otherwise deleteshard would have failed
clusterState = zkStateReader.getClusterState();
collection = clusterState.getCollection(collectionName);
}
final String asyncId = message.getStr(ASYNC);
Map<String, String> requestMap = new HashMap<>();
for (int i = 0; i < subRanges.size(); i++) {
String subSlice = subSlices.get(i);
String subShardName = subShardNames.get(i);
DocRouter.Range subRange = subRanges.get(i);
log.info("Creating slice " + subSlice + " of collection " + collectionName + " on " + nodeName);
Map<String, Object> propMap = new HashMap<>();
propMap.put(Overseer.QUEUE_OPERATION, CREATESHARD.toLower());
propMap.put(ZkStateReader.SHARD_ID_PROP, subSlice);
propMap.put(ZkStateReader.COLLECTION_PROP, collectionName);
propMap.put(ZkStateReader.SHARD_RANGE_PROP, subRange.toString());
propMap.put(ZkStateReader.SHARD_STATE_PROP, Slice.State.CONSTRUCTION.toString());
propMap.put(ZkStateReader.SHARD_PARENT_PROP, parentSlice.getName());
propMap.put("shard_parent_node", parentShardLeader.getNodeName());
propMap.put("shard_parent_zk_session", leaderZnodeStat.getEphemeralOwner());
DistributedQueue inQueue = Overseer.getStateUpdateQueue(zkStateReader.getZkClient());
inQueue.offer(Utils.toJSON(new ZkNodeProps(propMap)));
// wait until we are able to see the new shard in cluster state
ocmh.waitForNewShard(collectionName, subSlice);
// refresh cluster state
clusterState = zkStateReader.getClusterState();
log.info("Adding replica " + subShardName + " as part of slice " + subSlice + " of collection " + collectionName
+ " on " + nodeName);
propMap = new HashMap<>();
propMap.put(Overseer.QUEUE_OPERATION, ADDREPLICA.toLower());
propMap.put(COLLECTION_PROP, collectionName);
propMap.put(SHARD_ID_PROP, subSlice);
propMap.put("node", nodeName);
propMap.put(CoreAdminParams.NAME, subShardName);
// copy over property params:
for (String key : message.keySet()) {
if (key.startsWith(COLL_PROP_PREFIX)) {
propMap.put(key, message.getStr(key));
}
}
// add async param
if (asyncId != null) {
propMap.put(ASYNC, asyncId);
}
ocmh.addReplica(clusterState, new ZkNodeProps(propMap), results, null);
}
ocmh.processResponses(results, shardHandler, true, "SPLITSHARD failed to create subshard leaders", asyncId, requestMap);
for (String subShardName : subShardNames) {
// wait for parent leader to acknowledge the sub-shard core
log.info("Asking parent leader to wait for: " + subShardName + " to be alive on: " + nodeName);
String coreNodeName = ocmh.waitForCoreNodeName(collectionName, nodeName, subShardName);
CoreAdminRequest.WaitForState cmd = new CoreAdminRequest.WaitForState();
cmd.setCoreName(subShardName);
cmd.setNodeName(nodeName);
cmd.setCoreNodeName(coreNodeName);
cmd.setState(Replica.State.ACTIVE);
cmd.setCheckLive(true);
cmd.setOnlyIfLeader(true);
ModifiableSolrParams p = new ModifiableSolrParams(cmd.getParams());
ocmh.sendShardRequest(nodeName, p, shardHandler, asyncId, requestMap);
}
ocmh.processResponses(results, shardHandler, true, "SPLITSHARD timed out waiting for subshard leaders to come up",
asyncId, requestMap);
log.info("Successfully created all sub-shards for collection " + collectionName + " parent shard: " + slice
+ " on: " + parentShardLeader);
log.info("Splitting shard " + parentShardLeader.getName() + " as part of slice " + slice + " of collection "
+ collectionName + " on " + parentShardLeader);
ModifiableSolrParams params = new ModifiableSolrParams();
params.set(CoreAdminParams.ACTION, CoreAdminParams.CoreAdminAction.SPLIT.toString());
params.set(CoreAdminParams.CORE, parentShardLeader.getStr("core"));
for (int i = 0; i < subShardNames.size(); i++) {
String subShardName = subShardNames.get(i);
params.add(CoreAdminParams.TARGET_CORE, subShardName);
}
params.set(CoreAdminParams.RANGES, rangesStr);
ocmh.sendShardRequest(parentShardLeader.getNodeName(), params, shardHandler, asyncId, requestMap);
ocmh.processResponses(results, shardHandler, true, "SPLITSHARD failed to invoke SPLIT core admin command", asyncId,
requestMap);
log.info("Index on shard: " + nodeName + " split into two successfully");
// apply buffered updates on sub-shards
for (int i = 0; i < subShardNames.size(); i++) {
String subShardName = subShardNames.get(i);
log.info("Applying buffered updates on : " + subShardName);
params = new ModifiableSolrParams();
params.set(CoreAdminParams.ACTION, CoreAdminParams.CoreAdminAction.REQUESTAPPLYUPDATES.toString());
params.set(CoreAdminParams.NAME, subShardName);
ocmh.sendShardRequest(nodeName, params, shardHandler, asyncId, requestMap);
}
ocmh.processResponses(results, shardHandler, true, "SPLITSHARD failed while asking sub shard leaders" +
" to apply buffered updates", asyncId, requestMap);
log.info("Successfully applied buffered updates on : " + subShardNames);
// Replica creation for the new Slices
// look at the replication factor and see if it matches reality
// if it does not, find best nodes to create more cores
// TODO: Have replication factor decided in some other way instead of numShards for the parent
int repFactor = parentSlice.getReplicas().size();
// we need to look at every node and see how many cores it serves
// add our new cores to existing nodes serving the least number of cores
// but (for now) require that each core goes on a distinct node.
// TODO: add smarter options that look at the current number of cores per
// node?
// for now we just go random
Set<String> nodes = clusterState.getLiveNodes();
List<String> nodeList = new ArrayList<>(nodes.size());
nodeList.addAll(nodes);
// TODO: Have maxShardsPerNode param for this operation?
// Remove the node that hosts the parent shard for replica creation.
nodeList.remove(nodeName);
// TODO: change this to handle sharding a slice into > 2 sub-shards.
Map<ReplicaAssigner.Position, String> nodeMap = ocmh.identifyNodes(clusterState,
new ArrayList<>(clusterState.getLiveNodes()),
new ZkNodeProps(collection.getProperties()),
subSlices, repFactor - 1);
List<Map<String, Object>> replicas = new ArrayList<>((repFactor - 1) * 2);
for (Map.Entry<ReplicaAssigner.Position, String> entry : nodeMap.entrySet()) {
String sliceName = entry.getKey().shard;
String subShardNodeName = entry.getValue();
String shardName = collectionName + "_" + sliceName + "_replica" + (entry.getKey().index);
log.info("Creating replica shard " + shardName + " as part of slice " + sliceName + " of collection "
+ collectionName + " on " + subShardNodeName);
ZkNodeProps props = new ZkNodeProps(Overseer.QUEUE_OPERATION, ADDREPLICA.toLower(),
ZkStateReader.COLLECTION_PROP, collectionName,
ZkStateReader.SHARD_ID_PROP, sliceName,
ZkStateReader.CORE_NAME_PROP, shardName,
ZkStateReader.STATE_PROP, Replica.State.DOWN.toString(),
ZkStateReader.BASE_URL_PROP, zkStateReader.getBaseUrlForNodeName(subShardNodeName),
ZkStateReader.NODE_NAME_PROP, subShardNodeName);
Overseer.getStateUpdateQueue(zkStateReader.getZkClient()).offer(Utils.toJSON(props));
HashMap<String, Object> propMap = new HashMap<>();
propMap.put(Overseer.QUEUE_OPERATION, ADDREPLICA.toLower());
propMap.put(COLLECTION_PROP, collectionName);
propMap.put(SHARD_ID_PROP, sliceName);
propMap.put("node", subShardNodeName);
propMap.put(CoreAdminParams.NAME, shardName);
// copy over property params:
for (String key : message.keySet()) {
if (key.startsWith(COLL_PROP_PREFIX)) {
propMap.put(key, message.getStr(key));
}
}
// add async param
if (asyncId != null) {
propMap.put(ASYNC, asyncId);
}
// special flag param to instruct addReplica not to create the replica in cluster state again
propMap.put(SKIP_CREATE_REPLICA_IN_CLUSTER_STATE, "true");
replicas.add(propMap);
}
assert TestInjection.injectSplitFailureBeforeReplicaCreation();
long ephemeralOwner = leaderZnodeStat.getEphemeralOwner();
// compare against the ephemeralOwner of the parent leader node
leaderZnodeStat = zkStateReader.getZkClient().exists(ZkStateReader.LIVE_NODES_ZKNODE + "/" + parentShardLeader.getNodeName(), null, true);
if (leaderZnodeStat == null || ephemeralOwner != leaderZnodeStat.getEphemeralOwner()) {
// put sub-shards in recovery_failed state
DistributedQueue inQueue = Overseer.getStateUpdateQueue(zkStateReader.getZkClient());
Map<String, Object> propMap = new HashMap<>();
propMap.put(Overseer.QUEUE_OPERATION, OverseerAction.UPDATESHARDSTATE.toLower());
for (String subSlice : subSlices) {
propMap.put(subSlice, Slice.State.RECOVERY_FAILED.toString());
}
propMap.put(ZkStateReader.COLLECTION_PROP, collectionName);
ZkNodeProps m = new ZkNodeProps(propMap);
inQueue.offer(Utils.toJSON(m));
if (leaderZnodeStat == null) {
// the leader is not live anymore, fail the split!
throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "The shard leader node: " + parentShardLeader.getNodeName() + " is not live anymore!");
} else if (ephemeralOwner != leaderZnodeStat.getEphemeralOwner()) {
// there's a new leader, fail the split!
throw new SolrException(SolrException.ErrorCode.SERVER_ERROR,
"The zk session id for the shard leader node: " + parentShardLeader.getNodeName() + " has changed from "
+ ephemeralOwner + " to " + leaderZnodeStat.getEphemeralOwner() + ". This can cause data loss so we must abort the split");
}
}
// we must set the slice state into recovery before actually creating the replica cores
// this ensures that the logic inside Overseer to update sub-shard state to 'active'
// always gets a chance to execute. See SOLR-7673
if (repFactor == 1) {
// switch sub shard states to 'active'
log.info("Replication factor is 1 so switching shard states");
DistributedQueue inQueue = Overseer.getStateUpdateQueue(zkStateReader.getZkClient());
Map<String, Object> propMap = new HashMap<>();
propMap.put(Overseer.QUEUE_OPERATION, OverseerAction.UPDATESHARDSTATE.toLower());
propMap.put(slice, Slice.State.INACTIVE.toString());
for (String subSlice : subSlices) {
propMap.put(subSlice, Slice.State.ACTIVE.toString());
}
propMap.put(ZkStateReader.COLLECTION_PROP, collectionName);
ZkNodeProps m = new ZkNodeProps(propMap);
inQueue.offer(Utils.toJSON(m));
} else {
log.info("Requesting shard state be set to 'recovery'");
DistributedQueue inQueue = Overseer.getStateUpdateQueue(zkStateReader.getZkClient());
Map<String, Object> propMap = new HashMap<>();
propMap.put(Overseer.QUEUE_OPERATION, OverseerAction.UPDATESHARDSTATE.toLower());
for (String subSlice : subSlices) {
propMap.put(subSlice, Slice.State.RECOVERY.toString());
}
propMap.put(ZkStateReader.COLLECTION_PROP, collectionName);
ZkNodeProps m = new ZkNodeProps(propMap);
inQueue.offer(Utils.toJSON(m));
}
// now actually create replica cores on sub shard nodes
for (Map<String, Object> replica : replicas) {
ocmh.addReplica(clusterState, new ZkNodeProps(replica), results, null);
}
ocmh.processResponses(results, shardHandler, true, "SPLITSHARD failed to create subshard replicas", asyncId, requestMap);
log.info("Successfully created all replica shards for all sub-slices " + subSlices);
ocmh.commit(results, slice, parentShardLeader);
return true;
} catch (SolrException e) {
throw e;
} catch (Exception e) {
log.error("Error executing split operation for collection: " + collectionName + " parent shard: " + slice, e);
throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, null, e);
}
}
}