org.apache.solr.common.cloud.ZkStateReader Maven / Gradle / Ivy
package org.apache.solr.common.cloud;
/*
* 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.
*/
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.noggit.CharArr;
import org.noggit.JSONParser;
import org.noggit.JSONWriter;
import org.noggit.ObjectBuilder;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.SolrException.ErrorCode;
import org.apache.solr.common.util.ByteUtils;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.apache.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class ZkStateReader {
private static Logger log = LoggerFactory.getLogger(ZkStateReader.class);
public static final String BASE_URL_PROP = "base_url";
public static final String NODE_NAME_PROP = "node_name";
public static final String CORE_NODE_NAME_PROP = "core_node_name";
public static final String ROLES_PROP = "roles";
public static final String STATE_PROP = "state";
public static final String CORE_NAME_PROP = "core";
public static final String COLLECTION_PROP = "collection";
public static final String SHARD_ID_PROP = "shard";
public static final String REPLICA_PROP = "replica";
public static final String SHARD_RANGE_PROP = "shard_range";
public static final String SHARD_STATE_PROP = "shard_state";
public static final String SHARD_PARENT_PROP = "shard_parent";
public static final String NUM_SHARDS_PROP = "numShards";
public static final String LEADER_PROP = "leader";
public static final String COLLECTIONS_ZKNODE = "/collections";
public static final String LIVE_NODES_ZKNODE = "/live_nodes";
public static final String ALIASES = "/aliases.json";
public static final String CLUSTER_STATE = "/clusterstate.json";
public static final String RECOVERING = "recovering";
public static final String RECOVERY_FAILED = "recovery_failed";
public static final String ACTIVE = "active";
public static final String DOWN = "down";
public static final String SYNC = "sync";
private volatile ClusterState clusterState;
private static final long SOLRCLOUD_UPDATE_DELAY = Long.parseLong(System.getProperty("solrcloud.update.delay", "5000"));
public static final String LEADER_ELECT_ZKNODE = "/leader_elect";
public static final String SHARD_LEADERS_ZKNODE = "leaders";
//
// convenience methods... should these go somewhere else?
//
public static byte[] toJSON(Object o) {
CharArr out = new CharArr();
new JSONWriter(out, 2).write(o); // indentation by default
return toUTF8(out);
}
public static byte[] toUTF8(CharArr out) {
byte[] arr = new byte[out.size() << 2]; // is 4x the real worst-case upper-bound?
int nBytes = ByteUtils.UTF16toUTF8(out, 0, out.size(), arr, 0);
return Arrays.copyOf(arr, nBytes);
}
public static Object fromJSON(byte[] utf8) {
// convert directly from bytes to chars
// and parse directly from that instead of going through
// intermediate strings or readers
CharArr chars = new CharArr();
ByteUtils.UTF8toUTF16(utf8, 0, utf8.length, chars);
JSONParser parser = new JSONParser(chars.getArray(), chars.getStart(), chars.length());
try {
return ObjectBuilder.getVal(parser);
} catch (IOException e) {
throw new RuntimeException(e); // should never happen w/o using real IO
}
}
private static class ZKTF implements ThreadFactory {
private static ThreadGroup tg = new ThreadGroup("ZkStateReader");
@Override
public Thread newThread(Runnable r) {
Thread td = new Thread(tg, r);
td.setDaemon(true);
return td;
}
}
private ScheduledExecutorService updateCloudExecutor = Executors.newScheduledThreadPool(1, new ZKTF());
private boolean clusterStateUpdateScheduled;
private SolrZkClient zkClient;
private boolean closeClient = false;
private ZkCmdExecutor cmdExecutor;
private Aliases aliases = new Aliases();
private volatile boolean closed = false;
public ZkStateReader(SolrZkClient zkClient) {
this.zkClient = zkClient;
initZkCmdExecutor(zkClient.getZkClientTimeout());
}
public ZkStateReader(String zkServerAddress, int zkClientTimeout, int zkClientConnectTimeout) throws InterruptedException, TimeoutException, IOException {
closeClient = true;
initZkCmdExecutor(zkClientTimeout);
zkClient = new SolrZkClient(zkServerAddress, zkClientTimeout, zkClientConnectTimeout,
// on reconnect, reload cloud info
new OnReconnect() {
@Override
public void command() {
try {
ZkStateReader.this.createClusterStateWatchersAndUpdate();
} catch (KeeperException e) {
log.error("", e);
throw new ZooKeeperException(SolrException.ErrorCode.SERVER_ERROR,
"", e);
} catch (InterruptedException e) {
// Restore the interrupted status
Thread.currentThread().interrupt();
log.error("", e);
throw new ZooKeeperException(SolrException.ErrorCode.SERVER_ERROR,
"", e);
}
}
});
}
private void initZkCmdExecutor(int zkClientTimeout) {
// we must retry at least as long as the session timeout
cmdExecutor = new ZkCmdExecutor(zkClientTimeout);
}
// load and publish a new CollectionInfo
public void updateClusterState(boolean immediate) throws KeeperException, InterruptedException {
updateClusterState(immediate, false);
}
// load and publish a new CollectionInfo
public void updateLiveNodes() throws KeeperException, InterruptedException {
updateClusterState(true, true);
}
public Aliases getAliases() {
return aliases;
}
public synchronized void createClusterStateWatchersAndUpdate() throws KeeperException,
InterruptedException {
// We need to fetch the current cluster state and the set of live nodes
synchronized (getUpdateLock()) {
cmdExecutor.ensureExists(CLUSTER_STATE, zkClient);
cmdExecutor.ensureExists(ALIASES, zkClient);
log.info("Updating cluster state from ZooKeeper... ");
zkClient.exists(CLUSTER_STATE, new Watcher() {
@Override
public void process(WatchedEvent event) {
// session events are not change events,
// and do not remove the watcher
if (EventType.None.equals(event.getType())) {
return;
}
log.info("A cluster state change: {}, has occurred - updating... (live nodes size: {})", (event) , ZkStateReader.this.clusterState == null ? 0 : ZkStateReader.this.clusterState.getLiveNodes().size());
try {
// delayed approach
// ZkStateReader.this.updateClusterState(false, false);
synchronized (ZkStateReader.this.getUpdateLock()) {
// remake watch
final Watcher thisWatch = this;
Stat stat = new Stat();
byte[] data = zkClient.getData(CLUSTER_STATE, thisWatch, stat ,
true);
Set ln = ZkStateReader.this.clusterState.getLiveNodes();
ClusterState clusterState = ClusterState.load(stat.getVersion(), data, ln);
// update volatile
ZkStateReader.this.clusterState = clusterState;
}
} catch (KeeperException e) {
if (e.code() == KeeperException.Code.SESSIONEXPIRED
|| e.code() == KeeperException.Code.CONNECTIONLOSS) {
log.warn("ZooKeeper watch triggered, but Solr cannot talk to ZK");
return;
}
log.error("", e);
throw new ZooKeeperException(SolrException.ErrorCode.SERVER_ERROR,
"", e);
} catch (InterruptedException e) {
// Restore the interrupted status
Thread.currentThread().interrupt();
log.warn("", e);
return;
}
}
}, true);
}
synchronized (ZkStateReader.this.getUpdateLock()) {
List liveNodes = zkClient.getChildren(LIVE_NODES_ZKNODE,
new Watcher() {
@Override
public void process(WatchedEvent event) {
// session events are not change events,
// and do not remove the watcher
if (EventType.None.equals(event.getType())) {
return;
}
try {
// delayed approach
// ZkStateReader.this.updateClusterState(false, true);
synchronized (ZkStateReader.this.getUpdateLock()) {
List liveNodes = zkClient.getChildren(
LIVE_NODES_ZKNODE, this, true);
log.info("Updating live nodes... ({})", liveNodes.size());
Set liveNodesSet = new HashSet();
liveNodesSet.addAll(liveNodes);
ClusterState clusterState = new ClusterState(
ZkStateReader.this.clusterState.getZkClusterStateVersion(),
liveNodesSet, ZkStateReader.this.clusterState
.getCollectionStates());
ZkStateReader.this.clusterState = clusterState;
}
} catch (KeeperException e) {
if (e.code() == KeeperException.Code.SESSIONEXPIRED
|| e.code() == KeeperException.Code.CONNECTIONLOSS) {
log.warn("ZooKeeper watch triggered, but Solr cannot talk to ZK");
return;
}
log.error("", e);
throw new ZooKeeperException(
SolrException.ErrorCode.SERVER_ERROR, "", e);
} catch (InterruptedException e) {
// Restore the interrupted status
Thread.currentThread().interrupt();
log.warn("", e);
return;
}
}
}, true);
Set liveNodeSet = new HashSet();
liveNodeSet.addAll(liveNodes);
ClusterState clusterState = ClusterState.load(zkClient, liveNodeSet);
this.clusterState = clusterState;
zkClient.exists(ALIASES,
new Watcher() {
@Override
public void process(WatchedEvent event) {
// session events are not change events,
// and do not remove the watcher
if (EventType.None.equals(event.getType())) {
return;
}
try {
synchronized (ZkStateReader.this.getUpdateLock()) {
log.info("Updating aliases... ");
// remake watch
final Watcher thisWatch = this;
Stat stat = new Stat();
byte[] data = zkClient.getData(ALIASES, thisWatch, stat ,
true);
Aliases aliases = ClusterState.load(data);
ZkStateReader.this.aliases = aliases;
}
} catch (KeeperException e) {
if (e.code() == KeeperException.Code.SESSIONEXPIRED
|| e.code() == KeeperException.Code.CONNECTIONLOSS) {
log.warn("ZooKeeper watch triggered, but Solr cannot talk to ZK");
return;
}
log.error("", e);
throw new ZooKeeperException(
SolrException.ErrorCode.SERVER_ERROR, "", e);
} catch (InterruptedException e) {
// Restore the interrupted status
Thread.currentThread().interrupt();
log.warn("", e);
return;
}
}
}, true);
}
updateAliases();
}
// load and publish a new CollectionInfo
private synchronized void updateClusterState(boolean immediate,
final boolean onlyLiveNodes) throws KeeperException,
InterruptedException {
// build immutable CloudInfo
if (immediate) {
ClusterState clusterState;
synchronized (getUpdateLock()) {
List liveNodes = zkClient.getChildren(LIVE_NODES_ZKNODE, null,
true);
Set liveNodesSet = new HashSet();
liveNodesSet.addAll(liveNodes);
if (!onlyLiveNodes) {
log.info("Updating cloud state from ZooKeeper... ");
clusterState = ClusterState.load(zkClient, liveNodesSet);
} else {
log.info("Updating live nodes from ZooKeeper... ({})", liveNodesSet.size());
clusterState = new ClusterState(
ZkStateReader.this.clusterState.getZkClusterStateVersion(), liveNodesSet,
ZkStateReader.this.clusterState.getCollectionStates());
}
this.clusterState = clusterState;
}
} else {
if (clusterStateUpdateScheduled) {
log.info("Cloud state update for ZooKeeper already scheduled");
return;
}
log.info("Scheduling cloud state update from ZooKeeper...");
clusterStateUpdateScheduled = true;
updateCloudExecutor.schedule(new Runnable() {
@Override
public void run() {
log.info("Updating cluster state from ZooKeeper...");
synchronized (getUpdateLock()) {
clusterStateUpdateScheduled = false;
ClusterState clusterState;
try {
List liveNodes = zkClient.getChildren(LIVE_NODES_ZKNODE,
null, true);
Set liveNodesSet = new HashSet();
liveNodesSet.addAll(liveNodes);
if (!onlyLiveNodes) {
log.info("Updating cloud state from ZooKeeper... ");
clusterState = ClusterState.load(zkClient, liveNodesSet);
} else {
log.info("Updating live nodes from ZooKeeper... ");
clusterState = new ClusterState(ZkStateReader.this.clusterState.getZkClusterStateVersion(), liveNodesSet, ZkStateReader.this.clusterState.getCollectionStates());
}
ZkStateReader.this.clusterState = clusterState;
} catch (KeeperException e) {
if (e.code() == KeeperException.Code.SESSIONEXPIRED
|| e.code() == KeeperException.Code.CONNECTIONLOSS) {
log.warn("ZooKeeper watch triggered, but Solr cannot talk to ZK");
return;
}
log.error("", e);
throw new ZooKeeperException(
SolrException.ErrorCode.SERVER_ERROR, "", e);
} catch (InterruptedException e) {
// Restore the interrupted status
Thread.currentThread().interrupt();
log.error("", e);
throw new ZooKeeperException(
SolrException.ErrorCode.SERVER_ERROR, "", e);
}
// update volatile
ZkStateReader.this.clusterState = clusterState;
}
}
}, SOLRCLOUD_UPDATE_DELAY, TimeUnit.MILLISECONDS);
}
}
/**
* @return information about the cluster from ZooKeeper
*/
public ClusterState getClusterState() {
return clusterState;
}
public Object getUpdateLock() {
return this;
}
public void close() {
this.closed = true;
if (closeClient) {
zkClient.close();
}
}
abstract class RunnableWatcher implements Runnable {
Watcher watcher;
public RunnableWatcher(Watcher watcher){
this.watcher = watcher;
}
}
public String getLeaderUrl(String collection, String shard, int timeout)
throws InterruptedException, KeeperException {
ZkCoreNodeProps props = new ZkCoreNodeProps(getLeaderRetry(collection,
shard, timeout));
return props.getCoreUrl();
}
/**
* Get shard leader properties, with retry if none exist.
*/
public Replica getLeaderRetry(String collection, String shard) throws InterruptedException {
return getLeaderRetry(collection, shard, 1000);
}
/**
* Get shard leader properties, with retry if none exist.
*/
public Replica getLeaderRetry(String collection, String shard, int timeout) throws InterruptedException {
long timeoutAt = System.currentTimeMillis() + timeout;
while (System.currentTimeMillis() < timeoutAt && !closed) {
if (clusterState != null) {
Replica replica = clusterState.getLeader(collection, shard);
if (replica != null && getClusterState().liveNodesContain(replica.getNodeName())) {
return replica;
}
}
Thread.sleep(50);
}
throw new SolrException(ErrorCode.SERVICE_UNAVAILABLE, "No registered leader was found, collection:" + collection + " slice:" + shard);
}
/**
* Get path where shard leader properties live in zookeeper.
*/
public static String getShardLeadersPath(String collection, String shardId) {
return COLLECTIONS_ZKNODE + "/" + collection + "/"
+ SHARD_LEADERS_ZKNODE + (shardId != null ? ("/" + shardId)
: "");
}
public List getReplicaProps(String collection,
String shardId, String thisCoreNodeName, String coreName) {
return getReplicaProps(collection, shardId, thisCoreNodeName, coreName, null);
}
public List getReplicaProps(String collection,
String shardId, String thisCoreNodeName, String coreName, String mustMatchStateFilter) {
return getReplicaProps(collection, shardId, thisCoreNodeName, coreName, mustMatchStateFilter, null);
}
public List getReplicaProps(String collection,
String shardId, String thisCoreNodeName, String coreName, String mustMatchStateFilter, String mustNotMatchStateFilter) {
assert thisCoreNodeName != null;
ClusterState clusterState = this.clusterState;
if (clusterState == null) {
return null;
}
Map slices = clusterState.getSlicesMap(collection);
if (slices == null) {
throw new ZooKeeperException(ErrorCode.BAD_REQUEST,
"Could not find collection in zk: " + collection + " "
+ clusterState.getCollections());
}
Slice replicas = slices.get(shardId);
if (replicas == null) {
throw new ZooKeeperException(ErrorCode.BAD_REQUEST, "Could not find shardId in zk: " + shardId);
}
Map shardMap = replicas.getReplicasMap();
List nodes = new ArrayList(shardMap.size());
for (Entry entry : shardMap.entrySet()) {
ZkCoreNodeProps nodeProps = new ZkCoreNodeProps(entry.getValue());
String coreNodeName = entry.getValue().getName();
if (clusterState.liveNodesContain(nodeProps.getNodeName()) && !coreNodeName.equals(thisCoreNodeName)) {
if (mustMatchStateFilter == null || mustMatchStateFilter.equals(nodeProps.getState())) {
if (mustNotMatchStateFilter == null || !mustNotMatchStateFilter.equals(nodeProps.getState())) {
nodes.add(nodeProps);
}
}
}
}
if (nodes.size() == 0) {
// no replicas
return null;
}
return nodes;
}
public SolrZkClient getZkClient() {
return zkClient;
}
public void updateAliases() throws KeeperException, InterruptedException {
byte[] data = zkClient.getData(ALIASES, null, null, true);
Aliases aliases = ClusterState.load(data);
ZkStateReader.this.aliases = aliases;
}
}
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