/**
*
* 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.hadoop.hbase.client;
import java.io.Closeable;
import java.io.IOException;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.lang.reflect.UndeclaredThrowableException;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.NavigableMap;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Chore;
import org.apache.hadoop.hbase.DoNotRetryIOException;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HRegionLocation;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.MasterAdminProtocol;
import org.apache.hadoop.hbase.MasterMonitorProtocol;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.MasterProtocol;
import org.apache.hadoop.hbase.IpcProtocol;
import org.apache.hadoop.hbase.RegionMovedException;
import org.apache.hadoop.hbase.RemoteExceptionHandler;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.Stoppable;
import org.apache.hadoop.hbase.TableNotFoundException;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
import org.apache.hadoop.hbase.client.MetaScanner.MetaScannerVisitor;
import org.apache.hadoop.hbase.client.MetaScanner.MetaScannerVisitorBase;
import org.apache.hadoop.hbase.client.coprocessor.Batch;
import org.apache.hadoop.hbase.ipc.HBaseClientRPC;
import org.apache.hadoop.hbase.ipc.ProtobufRpcClientEngine;
import org.apache.hadoop.hbase.ipc.RpcClientEngine;
import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.protobuf.RequestConverter;
import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.TableSchema;
import org.apache.hadoop.hbase.protobuf.generated.MasterMonitorProtos.GetTableDescriptorsRequest;
import org.apache.hadoop.hbase.protobuf.generated.MasterMonitorProtos.GetTableDescriptorsResponse;
import org.apache.hadoop.hbase.security.User;
import org.apache.hadoop.hbase.util.Addressing;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.hadoop.hbase.util.SoftValueSortedMap;
import org.apache.hadoop.hbase.util.Triple;
import org.apache.hadoop.hbase.zookeeper.MasterAddressTracker;
import org.apache.hadoop.hbase.zookeeper.RootRegionTracker;
import org.apache.hadoop.hbase.zookeeper.ZKClusterId;
import org.apache.hadoop.hbase.zookeeper.ZKTableReadOnly;
import org.apache.hadoop.hbase.zookeeper.ZKUtil;
import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
import org.apache.hadoop.ipc.RemoteException;
import org.apache.zookeeper.KeeperException;
import com.google.protobuf.ServiceException;
/**
* A non-instantiable class that manages {@link HConnection}s.
* This class has a static Map of {@link HConnection} instances keyed by
* {@link Configuration}; all invocations of {@link #getConnection(Configuration)}
* that pass the same {@link Configuration} instance will be returned the same
* {@link HConnection} instance (Adding properties to a Configuration
* instance does not change its object identity). Sharing {@link HConnection}
* instances is usually what you want; all clients of the {@link HConnection}
* instances share the HConnections' cache of Region locations rather than each
* having to discover for itself the location of meta, root, etc. It makes
* sense for the likes of the pool of HTables class {@link HTablePool}, for
* instance (If concerned that a single {@link HConnection} is insufficient
* for sharing amongst clients in say an heavily-multithreaded environment,
* in practise its not proven to be an issue. Besides, {@link HConnection} is
* implemented atop Hadoop RPC and as of this writing, Hadoop RPC does a
* connection per cluster-member, exclusively).
*
* <p>But sharing connections
* makes clean up of {@link HConnection} instances a little awkward. Currently,
* clients cleanup by calling
* {@link #deleteConnection(Configuration)}. This will shutdown the
* zookeeper connection the HConnection was using and clean up all
* HConnection resources as well as stopping proxies to servers out on the
* cluster. Not running the cleanup will not end the world; it'll
* just stall the closeup some and spew some zookeeper connection failed
* messages into the log. Running the cleanup on a {@link HConnection} that is
* subsequently used by another will cause breakage so be careful running
* cleanup.
* <p>To create a {@link HConnection} that is not shared by others, you can
* create a new {@link Configuration} instance, pass this new instance to
* {@link #getConnection(Configuration)}, and then when done, close it up by
* doing something like the following:
* <pre>
* {@code
* Configuration newConfig = new Configuration(originalConf);
* HConnection connection = HConnectionManager.getConnection(newConfig);
* // Use the connection to your hearts' delight and then when done...
* HConnectionManager.deleteConnection(newConfig, true);
* }
* </pre>
* <p>Cleanup used to be done inside in a shutdown hook. On startup we'd
* register a shutdown hook that called {@link #deleteAllConnections()}
* on its way out but the order in which shutdown hooks run is not defined so
* were problematic for clients of HConnection that wanted to register their
* own shutdown hooks so we removed ours though this shifts the onus for
* cleanup to the client.
*/
@SuppressWarnings("serial")
@InterfaceAudience.Public
@InterfaceStability.Evolving
public class HConnectionManager {
// An LRU Map of HConnectionKey -> HConnection (TableServer). All
// access must be synchronized. This map is not private because tests
// need to be able to tinker with it.
static final Map<HConnectionKey, HConnectionImplementation> HBASE_INSTANCES;
public static final int MAX_CACHED_HBASE_INSTANCES;
/** Parameter name for what client protocol to use. */
public static final String CLIENT_PROTOCOL_CLASS = "hbase.clientprotocol.class";
/** Default client protocol class name. */
public static final String DEFAULT_CLIENT_PROTOCOL_CLASS = ClientProtocol.class.getName();
/** Parameter name for what admin protocol to use. */
public static final String REGION_PROTOCOL_CLASS = "hbase.adminprotocol.class";
/** Default admin protocol class name. */
public static final String DEFAULT_ADMIN_PROTOCOL_CLASS = AdminProtocol.class.getName();
private static final Log LOG = LogFactory.getLog(HConnectionManager.class);
static {
// We set instances to one more than the value specified for {@link
// HConstants#ZOOKEEPER_MAX_CLIENT_CNXNS}. By default, the zk default max
// connections to the ensemble from the one client is 30, so in that case we
// should run into zk issues before the LRU hit this value of 31.
MAX_CACHED_HBASE_INSTANCES = HBaseConfiguration.create().getInt(
HConstants.ZOOKEEPER_MAX_CLIENT_CNXNS,
HConstants.DEFAULT_ZOOKEPER_MAX_CLIENT_CNXNS) + 1;
HBASE_INSTANCES = new LinkedHashMap<HConnectionKey, HConnectionImplementation>(
(int) (MAX_CACHED_HBASE_INSTANCES / 0.75F) + 1, 0.75F, true) {
@Override
protected boolean removeEldestEntry(
Map.Entry<HConnectionKey, HConnectionImplementation> eldest) {
return size() > MAX_CACHED_HBASE_INSTANCES;
}
};
}
/*
* Non-instantiable.
*/
protected HConnectionManager() {
super();
}
/**
* Get the connection that goes with the passed <code>conf</code>
* configuration instance.
* If no current connection exists, method creates a new connection for the
* passed <code>conf</code> instance.
* @param conf configuration
* @return HConnection object for <code>conf</code>
* @throws ZooKeeperConnectionException
*/
public static HConnection getConnection(Configuration conf)
throws ZooKeeperConnectionException {
HConnectionKey connectionKey = new HConnectionKey(conf);
synchronized (HBASE_INSTANCES) {
HConnectionImplementation connection = HBASE_INSTANCES.get(connectionKey);
if (connection == null) {
connection = new HConnectionImplementation(conf, true);
HBASE_INSTANCES.put(connectionKey, connection);
} else if (connection.isClosed()) {
HConnectionManager.deleteConnection(connectionKey, true);
connection = new HConnectionImplementation(conf, true);
HBASE_INSTANCES.put(connectionKey, connection);
}
connection.incCount();
return connection;
}
}
/**
* Create a new HConnection instance using the passed <code>conf</code>
* instance.
* Note: This bypasses the usual HConnection life cycle management!
* Use this with caution, the caller is responsible for closing the
* created connection.
* @param conf configuration
* @return HConnection object for <code>conf</code>
* @throws ZooKeeperConnectionException
*/
public static HConnection createConnection(Configuration conf)
throws ZooKeeperConnectionException {
return new HConnectionImplementation(conf, false);
}
/**
* Delete connection information for the instance specified by configuration.
* If there are no more references to it, this will then close connection to
* the zookeeper ensemble and let go of all resources.
*
* @param conf
* configuration whose identity is used to find {@link HConnection}
* instance.
*/
public static void deleteConnection(Configuration conf) {
deleteConnection(new HConnectionKey(conf), false);
}
/**
* Delete stale connection information for the instance specified by configuration.
* This will then close connection to
* the zookeeper ensemble and let go of all resources.
*
* @param connection
*/
public static void deleteStaleConnection(HConnection connection) {
deleteConnection(connection, true);
}
/**
* Delete information for all connections.
* @throws IOException
*/
public static void deleteAllConnections() {
synchronized (HBASE_INSTANCES) {
Set<HConnectionKey> connectionKeys = new HashSet<HConnectionKey>();
connectionKeys.addAll(HBASE_INSTANCES.keySet());
for (HConnectionKey connectionKey : connectionKeys) {
deleteConnection(connectionKey, false);
}
HBASE_INSTANCES.clear();
}
}
private static void deleteConnection(HConnection connection, boolean staleConnection) {
synchronized (HBASE_INSTANCES) {
for (Entry<HConnectionKey, HConnectionImplementation> connectionEntry : HBASE_INSTANCES
.entrySet()) {
if (connectionEntry.getValue() == connection) {
deleteConnection(connectionEntry.getKey(), staleConnection);
break;
}
}
}
}
private static void deleteConnection(HConnectionKey connectionKey, boolean staleConnection) {
synchronized (HBASE_INSTANCES) {
HConnectionImplementation connection = HBASE_INSTANCES
.get(connectionKey);
if (connection != null) {
connection.decCount();
if (connection.isZeroReference() || staleConnection) {
HBASE_INSTANCES.remove(connectionKey);
connection.internalClose();
}
} else {
LOG.error("Connection not found in the list, can't delete it "+
"(connection key="+connectionKey+"). May be the key was modified?");
}
}
}
/**
* It is provided for unit test cases which verify the behavior of region
* location cache prefetch.
* @return Number of cached regions for the table.
* @throws ZooKeeperConnectionException
*/
static int getCachedRegionCount(Configuration conf,
final byte[] tableName)
throws IOException {
return execute(new HConnectable<Integer>(conf) {
@Override
public Integer connect(HConnection connection) {
return ((HConnectionImplementation) connection)
.getNumberOfCachedRegionLocations(tableName);
}
});
}
/**
* It's provided for unit test cases which verify the behavior of region
* location cache prefetch.
* @return true if the region where the table and row reside is cached.
* @throws ZooKeeperConnectionException
*/
static boolean isRegionCached(Configuration conf,
final byte[] tableName, final byte[] row) throws IOException {
return execute(new HConnectable<Boolean>(conf) {
@Override
public Boolean connect(HConnection connection) {
return ((HConnectionImplementation) connection).isRegionCached(tableName, row);
}
});
}
/**
* This class makes it convenient for one to execute a command in the context
* of a {@link HConnection} instance based on the given {@link Configuration}.
*
* <p>
* If you find yourself wanting to use a {@link HConnection} for a relatively
* short duration of time, and do not want to deal with the hassle of creating
* and cleaning up that resource, then you should consider using this
* convenience class.
*
* @param <T>
* the return type of the {@link HConnectable#connect(HConnection)}
* method.
*/
public static abstract class HConnectable<T> {
public Configuration conf;
protected HConnectable(Configuration conf) {
this.conf = conf;
}
public abstract T connect(HConnection connection) throws IOException;
}
/**
* This convenience method invokes the given {@link HConnectable#connect}
* implementation using a {@link HConnection} instance that lasts just for the
* duration of that invocation.
*
* @param <T> the return type of the connect method
* @param connectable the {@link HConnectable} instance
* @return the value returned by the connect method
* @throws IOException
*/
public static <T> T execute(HConnectable<T> connectable) throws IOException {
if (connectable == null || connectable.conf == null) {
return null;
}
Configuration conf = connectable.conf;
HConnection connection = HConnectionManager.getConnection(conf);
boolean connectSucceeded = false;
try {
T returnValue = connectable.connect(connection);
connectSucceeded = true;
return returnValue;
} finally {
try {
connection.close();
} catch (Exception e) {
if (connectSucceeded) {
throw new IOException("The connection to " + connection
+ " could not be deleted.", e);
}
}
}
}
/**
* Denotes a unique key to a {@link HConnection} instance.
*
* In essence, this class captures the properties in {@link Configuration}
* that may be used in the process of establishing a connection. In light of
* that, if any new such properties are introduced into the mix, they must be
* added to the {@link HConnectionKey#properties} list.
*
*/
public static class HConnectionKey {
final static String[] CONNECTION_PROPERTIES = new String[] {
HConstants.ZOOKEEPER_QUORUM, HConstants.ZOOKEEPER_ZNODE_PARENT,
HConstants.ZOOKEEPER_CLIENT_PORT,
HConstants.ZOOKEEPER_RECOVERABLE_WAITTIME,
HConstants.HBASE_CLIENT_PAUSE, HConstants.HBASE_CLIENT_RETRIES_NUMBER,
HConstants.HBASE_CLIENT_RPC_MAXATTEMPTS,
HConstants.HBASE_RPC_TIMEOUT_KEY,
HConstants.HBASE_CLIENT_PREFETCH_LIMIT,
HConstants.HBASE_META_SCANNER_CACHING,
HConstants.HBASE_CLIENT_INSTANCE_ID };
private Map<String, String> properties;
private String username;
public HConnectionKey(Configuration conf) {
Map<String, String> m = new HashMap<String, String>();
if (conf != null) {
for (String property : CONNECTION_PROPERTIES) {
String value = conf.get(property);
if (value != null) {
m.put(property, value);
}
}
}
this.properties = Collections.unmodifiableMap(m);
try {
User currentUser = User.getCurrent();
if (currentUser != null) {
username = currentUser.getName();
}
} catch (IOException ioe) {
LOG.warn("Error obtaining current user, skipping username in HConnectionKey",
ioe);
}
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
if (username != null) {
result = username.hashCode();
}
for (String property : CONNECTION_PROPERTIES) {
String value = properties.get(property);
if (value != null) {
result = prime * result + value.hashCode();
}
}
return result;
}
@edu.umd.cs.findbugs.annotations.SuppressWarnings (value="ES_COMPARING_STRINGS_WITH_EQ",
justification="Optimization")
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
HConnectionKey that = (HConnectionKey) obj;
if (this.username != null && !this.username.equals(that.username)) {
return false;
} else if (this.username == null && that.username != null) {
return false;
}
if (this.properties == null) {
if (that.properties != null) {
return false;
}
} else {
if (that.properties == null) {
return false;
}
for (String property : CONNECTION_PROPERTIES) {
String thisValue = this.properties.get(property);
String thatValue = that.properties.get(property);
//noinspection StringEquality
if (thisValue == thatValue) {
continue;
}
if (thisValue == null || !thisValue.equals(thatValue)) {
return false;
}
}
}
return true;
}
@Override
public String toString() {
return "HConnectionKey{" +
"properties=" + properties +
", username='" + username + '\'' +
'}';
}
}
/** Encapsulates connection to zookeeper and regionservers.*/
static class HConnectionImplementation implements HConnection, Closeable {
static final Log LOG = LogFactory.getLog(HConnectionImplementation.class);
private final Class<? extends AdminProtocol> adminClass;
private final Class<? extends ClientProtocol> clientClass;
private final long pause;
private final int numRetries;
private final int maxRPCAttempts;
private final int rpcTimeout;
private final int prefetchRegionLimit;
private volatile boolean closed;
private volatile boolean aborted;
private final Object metaRegionLock = new Object();
private final Object userRegionLock = new Object();
// We have a single lock for master & zk to prevent deadlocks. Having
// one lock for ZK and one lock for master is not possible:
// When creating a connection to master, we need a connection to ZK to get
// its address. But another thread could have taken the ZK lock, and could
// be waiting for the master lock => deadlock.
private final Object masterAndZKLock = new Object();
private long keepZooKeeperWatcherAliveUntil = Long.MAX_VALUE;
private final DelayedClosing delayedClosing =
DelayedClosing.createAndStart(this);
private final Configuration conf;
// client RPC
private RpcClientEngine rpcEngine;
// Known region ServerName.toString() -> RegionClient/Admin
private final ConcurrentHashMap<String, Map<String, IpcProtocol>> servers =
new ConcurrentHashMap<String, Map<String, IpcProtocol>>();
private final ConcurrentHashMap<String, String> connectionLock =
new ConcurrentHashMap<String, String>();
/**
* Map of table to table {@link HRegionLocation}s. The table key is made
* by doing a {@link Bytes#mapKey(byte[])} of the table's name.
*/
private final Map<Integer, SoftValueSortedMap<byte [], HRegionLocation>>
cachedRegionLocations =
new HashMap<Integer, SoftValueSortedMap<byte [], HRegionLocation>>();
// The presence of a server in the map implies it's likely that there is an
// entry in cachedRegionLocations that map to this server; but the absence
// of a server in this map guarentees that there is no entry in cache that
// maps to the absent server.
private final Set<String> cachedServers =
new HashSet<String>();
// region cache prefetch is enabled by default. this set contains all
// tables whose region cache prefetch are disabled.
private final Set<Integer> regionCachePrefetchDisabledTables =
new CopyOnWriteArraySet<Integer>();
private int refCount;
// indicates whether this connection's life cycle is managed (by us)
private final boolean managed;
private int customId;
/**
* constructor
* @param conf Configuration object
*/
@SuppressWarnings("unchecked")
public HConnectionImplementation(Configuration conf, boolean managed)
throws ZooKeeperConnectionException {
this.conf = conf;
this.managed = managed;
// ProtobufRpcClientEngine is the main RpcClientEngine implementation,
// but we maintain access through an interface to allow overriding for tests
this.rpcEngine = new ProtobufRpcClientEngine(conf);
String adminClassName = conf.get(REGION_PROTOCOL_CLASS,
DEFAULT_ADMIN_PROTOCOL_CLASS);
this.closed = false;
try {
this.adminClass =
(Class<? extends AdminProtocol>) Class.forName(adminClassName);
} catch (ClassNotFoundException e) {
throw new UnsupportedOperationException(
"Unable to find region server interface " + adminClassName, e);
}
String clientClassName = conf.get(CLIENT_PROTOCOL_CLASS,
DEFAULT_CLIENT_PROTOCOL_CLASS);
try {
this.clientClass =
(Class<? extends ClientProtocol>) Class.forName(clientClassName);
} catch (ClassNotFoundException e) {
throw new UnsupportedOperationException(
"Unable to find client protocol " + clientClassName, e);
}
this.pause = conf.getLong(HConstants.HBASE_CLIENT_PAUSE,
HConstants.DEFAULT_HBASE_CLIENT_PAUSE);
this.numRetries = conf.getInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER,
HConstants.DEFAULT_HBASE_CLIENT_RETRIES_NUMBER);
this.maxRPCAttempts = conf.getInt(
HConstants.HBASE_CLIENT_RPC_MAXATTEMPTS,
HConstants.DEFAULT_HBASE_CLIENT_RPC_MAXATTEMPTS);
this.rpcTimeout = conf.getInt(
HConstants.HBASE_RPC_TIMEOUT_KEY,
HConstants.DEFAULT_HBASE_RPC_TIMEOUT);
this.prefetchRegionLimit = conf.getInt(
HConstants.HBASE_CLIENT_PREFETCH_LIMIT,
HConstants.DEFAULT_HBASE_CLIENT_PREFETCH_LIMIT);
retrieveClusterId();
}
/**
* An identifier that will remain the same for a given connection.
* @return
*/
public String toString(){
return "hconnection 0x" + Integer.toHexString( hashCode() );
}
private String clusterId = null;
public final void retrieveClusterId(){
if (conf.get(HConstants.CLUSTER_ID) != null){
return;
}
// No synchronized here, worse case we will retrieve it twice, that's
// not an issue.
if (this.clusterId == null){
this.clusterId = conf.get(HConstants.CLUSTER_ID);
if (this.clusterId == null) {
ZooKeeperKeepAliveConnection zkw = null;
try {
zkw = getKeepAliveZooKeeperWatcher();
this.clusterId = ZKClusterId.readClusterIdZNode(zkw);
if (clusterId == null) {
LOG.info("ClusterId read in ZooKeeper is null");
}
} catch (KeeperException e) {
LOG.warn("Can't retrieve clusterId from Zookeeper", e);
} catch (IOException e) {
LOG.warn("Can't retrieve clusterId from Zookeeper", e);
} finally {
if (zkw != null) {
zkw.close();
}
}
if (this.clusterId == null) {
this.clusterId = "default";
}
LOG.info("ClusterId is " + clusterId);
}
}
conf.set(HConstants.CLUSTER_ID, clusterId);
}
@Override
public Configuration getConfiguration() {
return this.conf;
}
private static class MasterProtocolState {
public MasterProtocol protocol;
public int userCount;
public long keepAliveUntil = Long.MAX_VALUE;
public final Class<? extends MasterProtocol> protocolClass;
public MasterProtocolState (
final Class<? extends MasterProtocol> protocolClass) {
this.protocolClass = protocolClass;
}
}
/**
* Create a new Master proxy. Try once only.
*/
private MasterProtocol createMasterInterface(
MasterProtocolState masterProtocolState)
throws IOException, KeeperException, ServiceException {
ZooKeeperKeepAliveConnection zkw;
try {
zkw = getKeepAliveZooKeeperWatcher();
} catch (IOException e) {
throw new ZooKeeperConnectionException("Can't connect to ZooKeeper", e);
}
try {
checkIfBaseNodeAvailable(zkw);
ServerName sn = MasterAddressTracker.getMasterAddress(zkw);
if (sn == null) {
String msg =
"ZooKeeper available but no active master location found";
LOG.info(msg);
throw new MasterNotRunningException(msg);
}
InetSocketAddress isa =
new InetSocketAddress(sn.getHostname(), sn.getPort());
MasterProtocol tryMaster = rpcEngine.getProxy(
masterProtocolState.protocolClass,
isa, this.conf, this.rpcTimeout);
if (tryMaster.isMasterRunning(
null, RequestConverter.buildIsMasterRunningRequest()).getIsMasterRunning()) {
return tryMaster;
} else {
String msg = "Can create a proxy to master, but it is not running";
LOG.info(msg);
throw new MasterNotRunningException(msg);
}
} finally {
zkw.close();
}
}
/**
* Create a master, retries if necessary.
*/
@edu.umd.cs.findbugs.annotations.SuppressWarnings (value="SWL_SLEEP_WITH_LOCK_HELD")
private MasterProtocol createMasterWithRetries(
MasterProtocolState masterProtocolState) throws MasterNotRunningException {
// The lock must be at the beginning to prevent multiple master creation
// (and leaks) in a multithread context
synchronized (this.masterAndZKLock) {
Exception exceptionCaught = null;
MasterProtocol master = null;
int tries = 0;
while (
!this.closed && master == null
) {
tries++;
try {
master = createMasterInterface(masterProtocolState);
} catch (IOException e) {
exceptionCaught = e;
} catch (KeeperException e) {
exceptionCaught = e;
} catch (ServiceException e) {
exceptionCaught = e;
}
if (exceptionCaught != null)
// It failed. If it's not the last try, we're going to wait a little
if (tries < numRetries) {
// tries at this point is 1 or more; decrement to start from 0.
long pauseTime = ConnectionUtils.getPauseTime(this.pause, tries - 1);
LOG.info("getMaster attempt " + tries + " of " + numRetries +
" failed; retrying after sleep of " +pauseTime, exceptionCaught);
try {
Thread.sleep(pauseTime);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new RuntimeException(
"Thread was interrupted while trying to connect to master.", e);
}
} else {
// Enough tries, we stop now
LOG.info("getMaster attempt " + tries + " of " + numRetries +
" failed; no more retrying.", exceptionCaught);
throw new MasterNotRunningException(exceptionCaught);
}
}
if (master == null) {
// implies this.closed true
throw new MasterNotRunningException(
"Connection was closed while trying to get master");
}
return master;
}
}
private void checkIfBaseNodeAvailable(ZooKeeperWatcher zkw)
throws MasterNotRunningException {
String errorMsg;
try {
if (ZKUtil.checkExists(zkw, zkw.baseZNode) == -1) {
errorMsg = "The node " + zkw.baseZNode+" is not in ZooKeeper. "
+ "It should have been written by the master. "
+ "Check the value configured in 'zookeeper.znode.parent'. "
+ "There could be a mismatch with the one configured in the master.";
LOG.error(errorMsg);
throw new MasterNotRunningException(errorMsg);
}
} catch (KeeperException e) {
errorMsg = "Can't get connection to ZooKeeper: " + e.getMessage();
LOG.error(errorMsg);
throw new MasterNotRunningException(errorMsg, e);
}
}
/**
* @return true if the master is running, throws an exception otherwise
* @throws MasterNotRunningException - if the master is not running
* @throws ZooKeeperConnectionException
*/
@Override
public boolean isMasterRunning()
throws MasterNotRunningException, ZooKeeperConnectionException {
// When getting the master proxy connection, we check it's running,
// so if there is no exception, it means we've been able to get a
// connection on a running master
getKeepAliveMasterMonitor().close();
return true;
}
@Override
public HRegionLocation getRegionLocation(final byte [] name,
final byte [] row, boolean reload)
throws IOException {
return reload? relocateRegion(name, row): locateRegion(name, row);
}
@Override
public boolean isTableEnabled(byte[] tableName) throws IOException {
return testTableOnlineState(tableName, true);
}
@Override
public boolean isTableDisabled(byte[] tableName) throws IOException {
return testTableOnlineState(tableName, false);
}
@Override
public boolean isTableAvailable(final byte[] tableName) throws IOException {
final AtomicBoolean available = new AtomicBoolean(true);
final AtomicInteger regionCount = new AtomicInteger(0);
MetaScannerVisitor visitor = new MetaScannerVisitorBase() {
@Override
public boolean processRow(Result row) throws IOException {
HRegionInfo info = MetaScanner.getHRegionInfo(row);
if (info != null) {
if (Bytes.equals(tableName, info.getTableName())) {
ServerName server = HRegionInfo.getServerName(row);
if (server == null) {
available.set(false);
return false;
}
regionCount.incrementAndGet();
}
}
return true;
}
};
MetaScanner.metaScan(conf, visitor);
return available.get() && (regionCount.get() > 0);
}
/*
* @param True if table is online
*/
private boolean testTableOnlineState(byte [] tableName, boolean online)
throws IOException {
if (Bytes.equals(tableName, HConstants.ROOT_TABLE_NAME)) {
// The root region is always enabled
return online;
}
String tableNameStr = Bytes.toString(tableName);
ZooKeeperKeepAliveConnection zkw = getKeepAliveZooKeeperWatcher();
try {
if (online) {
return ZKTableReadOnly.isEnabledTable(zkw, tableNameStr);
}
return ZKTableReadOnly.isDisabledTable(zkw, tableNameStr);
} catch (KeeperException e) {
throw new IOException("Enable/Disable failed", e);
}finally {
zkw.close();
}
}
@Override
public HRegionLocation locateRegion(final byte[] regionName) throws IOException {
return locateRegion(HRegionInfo.getTableName(regionName),
HRegionInfo.getStartKey(regionName), false, true);
}
@Override
public List<HRegionLocation> locateRegions(final byte[] tableName)
throws IOException {
return locateRegions (tableName, false, true);
}
@Override
public List<HRegionLocation> locateRegions(final byte[] tableName, final boolean useCache,
final boolean offlined) throws IOException {
NavigableMap<HRegionInfo, ServerName> regions = MetaScanner.allTableRegions(conf, tableName,
offlined);
final List<HRegionLocation> locations = new ArrayList<HRegionLocation>();
for (HRegionInfo regionInfo : regions.keySet()) {
locations.add(locateRegion(tableName, regionInfo.getStartKey(), useCache, true));
}
return locations;
}
@Override
public HRegionLocation locateRegion(final byte [] tableName,
final byte [] row)
throws IOException{
return locateRegion(tableName, row, true, true);
}
@Override
public HRegionLocation relocateRegion(final byte [] tableName,
final byte [] row)
throws IOException{
// Since this is an explicit request not to use any caching, finding
// disabled tables should not be desirable. This will ensure that an exception is thrown when
// the first time a disabled table is interacted with.
if (isTableDisabled(tableName)) {
throw new DoNotRetryIOException(Bytes.toString(tableName) + " is disabled.");
}
return locateRegion(tableName, row, false, true);
}
private HRegionLocation locateRegion(final byte [] tableName,
final byte [] row, boolean useCache, boolean retry)
throws IOException {
if (this.closed) throw new IOException(toString() + " closed");
if (tableName == null || tableName.length == 0) {
throw new IllegalArgumentException(
"table name cannot be null or zero length");
}
if (Bytes.equals(tableName, HConstants.ROOT_TABLE_NAME)) {
ZooKeeperKeepAliveConnection zkw = getKeepAliveZooKeeperWatcher();
try {
LOG.debug("Looking up root region location in ZK," +
" connection=" + this);
ServerName servername =
RootRegionTracker.blockUntilAvailable(zkw, this.rpcTimeout);
LOG.debug("Looked up root region location, connection=" + this +
"; serverName=" + ((servername == null) ? "null" : servername));
if (servername == null) return null;
return new HRegionLocation(HRegionInfo.ROOT_REGIONINFO, servername.getHostname(),
servername.getPort(), 0);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
return null;
} finally {
zkw.close();
}
} else if (Bytes.equals(tableName, HConstants.META_TABLE_NAME)) {
return locateRegionInMeta(HConstants.ROOT_TABLE_NAME, tableName, row,
useCache, metaRegionLock, retry);
} else {
// Region not in the cache - have to go to the meta RS
return locateRegionInMeta(HConstants.META_TABLE_NAME, tableName, row,
useCache, userRegionLock, retry);
}
}
/*
* Search .META. for the HRegionLocation info that contains the table and
* row we're seeking. It will prefetch certain number of regions info and
* save them to the global region cache.
*/
private void prefetchRegionCache(final byte[] tableName,
final byte[] row) {
// Implement a new visitor for MetaScanner, and use it to walk through
// the .META.
MetaScannerVisitor visitor = new MetaScannerVisitorBase() {
public boolean processRow(Result result) throws IOException {
try {
HRegionInfo regionInfo = MetaScanner.getHRegionInfo(result);
if (regionInfo == null) {
return true;
}
// possible we got a region of a different table...
if (!Bytes.equals(regionInfo.getTableName(), tableName)) {
return false; // stop scanning
}
if (regionInfo.isOffline()) {
// don't cache offline regions
return true;
}
ServerName serverName = HRegionInfo.getServerName(result);
if (serverName == null) {
return true; // don't cache it
}
// instantiate the location
HRegionLocation loc = new HRegionLocation(regionInfo, serverName.getHostname(),
serverName.getPort(), HRegionInfo.getSeqNumDuringOpen(result));
// cache this meta entry
cacheLocation(tableName, null, loc);
return true;
} catch (RuntimeException e) {
throw new IOException(e);
}
}
};
try {
// pre-fetch certain number of regions info at region cache.
MetaScanner.metaScan(conf, visitor, tableName, row,
this.prefetchRegionLimit);
} catch (IOException e) {
LOG.warn("Encountered problems when prefetch META table: ", e);
}
}
/*
* Search one of the meta tables (-ROOT- or .META.) for the HRegionLocation
* info that contains the table and row we're seeking.
*/
private HRegionLocation locateRegionInMeta(final byte [] parentTable,
final byte [] tableName, final byte [] row, boolean useCache,
Object regionLockObject, boolean retry)
throws IOException {
HRegionLocation location;
// If we are supposed to be using the cache, look in the cache to see if
// we already have the region.
if (useCache) {
location = getCachedLocation(tableName, row);
if (location != null) {
return location;
}
}
int localNumRetries = retry ? numRetries : 1;
// build the key of the meta region we should be looking for.
// the extra 9's on the end are necessary to allow "exact" matches
// without knowing the precise region names.
byte [] metaKey = HRegionInfo.createRegionName(tableName, row,
HConstants.NINES, false);
for (int tries = 0; true; tries++) {
if (tries >= localNumRetries) {
throw new NoServerForRegionException("Unable to find region for "
+ Bytes.toStringBinary(row) + " after " + numRetries + " tries.");
}
HRegionLocation metaLocation = null;
try {
// locate the root or meta region
metaLocation = locateRegion(parentTable, metaKey, true, false);
// If null still, go around again.
if (metaLocation == null) continue;
ClientProtocol server =
getClient(metaLocation.getHostname(), metaLocation.getPort());
Result regionInfoRow = null;
// This block guards against two threads trying to load the meta
// region at the same time. The first will load the meta region and
// the second will use the value that the first one found.
synchronized (regionLockObject) {
// If the parent table is META, we may want to pre-fetch some
// region info into the global region cache for this table.
if (Bytes.equals(parentTable, HConstants.META_TABLE_NAME) &&
(getRegionCachePrefetch(tableName)) ) {
prefetchRegionCache(tableName, row);
}
// Check the cache again for a hit in case some other thread made the
// same query while we were waiting on the lock. If not supposed to
// be using the cache, delete any existing cached location so it won't
// interfere.
if (useCache) {
location = getCachedLocation(tableName, row);
if (location != null) {
return location;
}
} else {
forceDeleteCachedLocation(tableName, row);
}
// Query the root or meta region for the location of the meta region
regionInfoRow = ProtobufUtil.getRowOrBefore(server,
metaLocation.getRegionInfo().getRegionName(), metaKey,
HConstants.CATALOG_FAMILY, customId);
}
if (regionInfoRow == null) {
throw new TableNotFoundException(Bytes.toString(tableName));
}
// convert the row result into the HRegionLocation we need!
HRegionInfo regionInfo = MetaScanner.getHRegionInfo(regionInfoRow);
if (regionInfo == null) {
throw new IOException("HRegionInfo was null or empty in " +
Bytes.toString(parentTable) + ", row=" + regionInfoRow);
}
// possible we got a region of a different table...
if (!Bytes.equals(regionInfo.getTableName(), tableName)) {
throw new TableNotFoundException(
"Table '" + Bytes.toString(tableName) + "' was not found, got: " +
Bytes.toString(regionInfo.getTableName()) + ".");
}
if (regionInfo.isSplit()) {
throw new RegionOfflineException("the only available region for" +
" the required row is a split parent," +
" the daughters should be online soon: " +
regionInfo.getRegionNameAsString());
}
if (regionInfo.isOffline()) {
throw new RegionOfflineException("the region is offline, could" +
" be caused by a disable table call: " +
regionInfo.getRegionNameAsString());
}
ServerName serverName = HRegionInfo.getServerName(regionInfoRow);
if (serverName == null) {
throw new NoServerForRegionException("No server address listed " +
"in " + Bytes.toString(parentTable) + " for region " +
regionInfo.getRegionNameAsString() + " containing row " +
Bytes.toStringBinary(row));
}
// Instantiate the location
location = new HRegionLocation(regionInfo, serverName.getHostname(),
serverName.getPort(), HRegionInfo.getSeqNumDuringOpen(regionInfoRow));
cacheLocation(tableName, null, location);
return location;
} catch (TableNotFoundException e) {
// if we got this error, probably means the table just plain doesn't
// exist. rethrow the error immediately. this should always be coming
// from the HTable constructor.
throw e;
} catch (IOException e) {
if (e instanceof RemoteException) {
e = RemoteExceptionHandler.decodeRemoteException((RemoteException) e);
}
if (tries < numRetries - 1) {
if (LOG.isDebugEnabled()) {
LOG.debug("locateRegionInMeta parentTable=" +
Bytes.toString(parentTable) + ", metaLocation=" +
((metaLocation == null)? "null": "{" + metaLocation + "}") +
", attempt=" + tries + " of " +
this.numRetries + " failed; retrying after sleep of " +
ConnectionUtils.getPauseTime(this.pause, tries) + " because: " + e.getMessage());
}
} else {
throw e;
}
// Only relocate the parent region if necessary
if(!(e instanceof RegionOfflineException ||
e instanceof NoServerForRegionException)) {
relocateRegion(parentTable, metaKey);
}
}
try{
Thread.sleep(ConnectionUtils.getPauseTime(this.pause, tries));
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
throw new IOException("Giving up trying to location region in " +
"meta: thread is interrupted.");
}
}
}
/*
* Search the cache for a location that fits our table and row key.
* Return null if no suitable region is located. TODO: synchronization note
*
* <p>TODO: This method during writing consumes 15% of CPU doing lookup
* into the Soft Reference SortedMap. Improve.
*
* @param tableName
* @param row
* @return Null or region location found in cache.
*/
HRegionLocation getCachedLocation(final byte [] tableName,
final byte [] row) {
SoftValueSortedMap<byte [], HRegionLocation> tableLocations =
getTableLocations(tableName);
// start to examine the cache. we can only do cache actions
// if there's something in the cache for this table.
if (tableLocations.isEmpty()) {
return null;
}
HRegionLocation possibleRegion = tableLocations.get(row);
if (possibleRegion != null) {
return possibleRegion;
}
possibleRegion = tableLocations.lowerValueByKey(row);
if (possibleRegion == null) {
return null;
}
// make sure that the end key is greater than the row we're looking
// for, otherwise the row actually belongs in the next region, not
// this one. the exception case is when the endkey is
// HConstants.EMPTY_END_ROW, signifying that the region we're
// checking is actually the last region in the table.
byte[] endKey = possibleRegion.getRegionInfo().getEndKey();
if (Bytes.equals(endKey, HConstants.EMPTY_END_ROW) ||
KeyValue.getRowComparator(tableName).compareRows(
endKey, 0, endKey.length, row, 0, row.length) > 0) {
return possibleRegion;
}
// Passed all the way through, so we got nothin - complete cache miss
return null;
}
/**
* Delete a cached location, no matter what it is. Called when we were told to not use cache.
* @param tableName tableName
* @param row
*/
void forceDeleteCachedLocation(final byte [] tableName, final byte [] row) {
HRegionLocation rl = null;
synchronized (this.cachedRegionLocations) {
Map<byte[], HRegionLocation> tableLocations =
getTableLocations(tableName);
// start to examine the cache. we can only do cache actions
// if there's something in the cache for this table.
if (!tableLocations.isEmpty()) {
rl = getCachedLocation(tableName, row);
if (rl != null) {
tableLocations.remove(rl.getRegionInfo().getStartKey());
}
}
}
if ((rl != null) && LOG.isDebugEnabled()) {
LOG.debug("Removed " + rl.getHostname() + ":" + rl.getPort()
+ " as a location of " + rl.getRegionInfo().getRegionNameAsString() +
" for tableName=" + Bytes.toString(tableName) +
" from cache to make sure we don't use cache for " + Bytes.toStringBinary(row));
}
}
@Override
public void clearCaches(String sn) {
clearCachedLocationForServer(sn);
}
/*
* Delete all cached entries of a table that maps to a specific location.
*
* @param tablename
* @param server
*/
private void clearCachedLocationForServer(final String server) {
boolean deletedSomething = false;
synchronized (this.cachedRegionLocations) {
if (!cachedServers.contains(server)) {
return;
}
for (Map<byte[], HRegionLocation> tableLocations :
cachedRegionLocations.values()) {
for (Entry<byte[], HRegionLocation> e : tableLocations.entrySet()) {
if (e.getValue().getHostnamePort().equals(server)) {
tableLocations.remove(e.getKey());
deletedSomething = true;
}
}
}
cachedServers.remove(server);
}
if (deletedSomething && LOG.isDebugEnabled()) {
LOG.debug("Removed all cached region locations that map to " + server);
}
}
/*
* @param tableName
* @return Map of cached locations for passed <code>tableName</code>
*/
private SoftValueSortedMap<byte [], HRegionLocation> getTableLocations(
final byte [] tableName) {
// find the map of cached locations for this table
Integer key = Bytes.mapKey(tableName);
SoftValueSortedMap<byte [], HRegionLocation> result;
synchronized (this.cachedRegionLocations) {
result = this.cachedRegionLocations.get(key);
// if tableLocations for this table isn't built yet, make one
if (result == null) {
result = new SoftValueSortedMap<byte [], HRegionLocation>(
Bytes.BYTES_COMPARATOR);
this.cachedRegionLocations.put(key, result);
}
}
return result;
}
@Override
public void clearRegionCache() {
synchronized(this.cachedRegionLocations) {
this.cachedRegionLocations.clear();
this.cachedServers.clear();
}
}
@Override
public void clearRegionCache(final byte [] tableName) {
synchronized (this.cachedRegionLocations) {
this.cachedRegionLocations.remove(Bytes.mapKey(tableName));
}
}
/**
* Put a newly discovered HRegionLocation into the cache.
* @param tableName The table name.
* @param source the source of the new location, if it's not coming from meta
* @param location the new location
*/
private void cacheLocation(final byte [] tableName, final HRegionLocation source,
final HRegionLocation location) {
boolean isFromMeta = (source == null);
byte [] startKey = location.getRegionInfo().getStartKey();
Map<byte [], HRegionLocation> tableLocations =
getTableLocations(tableName);
boolean isNewCacheEntry = false;
boolean isStaleUpdate = false;
HRegionLocation oldLocation = null;
synchronized (this.cachedRegionLocations) {
cachedServers.add(location.getHostnamePort());
oldLocation = tableLocations.get(startKey);
isNewCacheEntry = (oldLocation == null);
// If the server in cache sends us a redirect, assume it's always valid.
if (!isNewCacheEntry && !oldLocation.equals(source)) {
long newLocationSeqNum = location.getSeqNum();
// Meta record is stale - some (probably the same) server has closed the region
// with later seqNum and told us about the new location.
boolean isStaleMetaRecord = isFromMeta && (oldLocation.getSeqNum() > newLocationSeqNum);
// Same as above for redirect. However, in this case, if the number is equal to previous
// record, the most common case is that first the region was closed with seqNum, and then
// opened with the same seqNum; hence we will ignore the redirect.
// There are so many corner cases with various combinations of opens and closes that
// an additional counter on top of seqNum would be necessary to handle them all.
boolean isStaleRedirect = !isFromMeta && (oldLocation.getSeqNum() >= newLocationSeqNum);
isStaleUpdate = (isStaleMetaRecord || isStaleRedirect);
}
if (!isStaleUpdate) {
tableLocations.put(startKey, location);
}
}
if (isNewCacheEntry) {
LOG.debug("Cached location for " +
location.getRegionInfo().getRegionNameAsString() +
" is " + location.getHostnamePort());
} else if (isStaleUpdate && !location.equals(oldLocation)) {
LOG.debug("Ignoring stale location update for "
+ location.getRegionInfo().getRegionNameAsString() + ": "
+ location.getHostnamePort() + " at " + location.getSeqNum() + "; local "
+ oldLocation.getHostnamePort() + " at " + oldLocation.getSeqNum());
}
}
@Override
public AdminProtocol getAdmin(final String hostname,
final int port) throws IOException {
return getAdmin(hostname, port, false);
}
@Override
public ClientProtocol getClient(final String hostname, final int port)
throws IOException {
return (ClientProtocol)getProtocol(hostname, port, clientClass);
}
@Override
public AdminProtocol getAdmin(final String hostname, final int port,
final boolean master)
throws IOException {
return (AdminProtocol)getProtocol(hostname, port, adminClass);
}
/**
* Either the passed <code>isa</code> is null or <code>hostname</code>
* can be but not both.
* @param hostname
* @param port
* @param protocolClass
* @return Proxy.
* @throws IOException
*/
IpcProtocol getProtocol(final String hostname,
final int port, final Class <? extends IpcProtocol> protocolClass)
throws IOException {
String rsName = Addressing.createHostAndPortStr(hostname, port);
// See if we already have a connection (common case)
Map<String, IpcProtocol> protocols = this.servers.get(rsName);
if (protocols == null) {
protocols = new HashMap<String, IpcProtocol>();
Map<String, IpcProtocol> existingProtocols =
this.servers.putIfAbsent(rsName, protocols);
if (existingProtocols != null) {
protocols = existingProtocols;
}
}
String protocol = protocolClass.getName();
IpcProtocol server = protocols.get(protocol);
if (server == null) {
// create a unique lock for this RS + protocol (if necessary)
String lockKey = protocol + "@" + rsName;
this.connectionLock.putIfAbsent(lockKey, lockKey);
// get the RS lock
synchronized (this.connectionLock.get(lockKey)) {
// do one more lookup in case we were stalled above
server = protocols.get(protocol);
if (server == null) {
try {
// Only create isa when we need to.
InetSocketAddress address = new InetSocketAddress(hostname, port);
// definitely a cache miss. establish an RPC for this RS
server = HBaseClientRPC.waitForProxy(rpcEngine, protocolClass, address, this.conf,
this.maxRPCAttempts, this.rpcTimeout, this.rpcTimeout);
protocols.put(protocol, server);
} catch (RemoteException e) {
LOG.warn("RemoteException connecting to RS", e);
// Throw what the RemoteException was carrying.
throw e.unwrapRemoteException();
}
}
}
}
return server;
}
@Override
@Deprecated
public ZooKeeperWatcher getZooKeeperWatcher()
throws ZooKeeperConnectionException {
canCloseZKW = false;
try {
return getKeepAliveZooKeeperWatcher();
} catch (ZooKeeperConnectionException e){
throw e;
}catch (IOException e) {
// Encapsulate exception to keep interface
throw new ZooKeeperConnectionException(
"Can't create a zookeeper connection", e);
}
}
private ZooKeeperKeepAliveConnection keepAliveZookeeper;
private int keepAliveZookeeperUserCount;
private boolean canCloseZKW = true;
// keepAlive time, in ms. No reason to make it configurable.
private static final long keepAlive = 5 * 60 * 1000;
/**
* Retrieve a shared ZooKeeperWatcher. You must close it it once you've have
* finished with it.
* @return The shared instance. Never returns null.
*/
public ZooKeeperKeepAliveConnection getKeepAliveZooKeeperWatcher()
throws IOException {
synchronized (masterAndZKLock) {
if (keepAliveZookeeper == null) {
// We don't check that our link to ZooKeeper is still valid
// But there is a retry mechanism in the ZooKeeperWatcher itself
keepAliveZookeeper = new ZooKeeperKeepAliveConnection(
conf, this.toString(), this);
}
keepAliveZookeeperUserCount++;
keepZooKeeperWatcherAliveUntil = Long.MAX_VALUE;
return keepAliveZookeeper;
}
}
void releaseZooKeeperWatcher(ZooKeeperWatcher zkw) {
if (zkw == null){
return;
}
synchronized (masterAndZKLock) {
--keepAliveZookeeperUserCount;
if (keepAliveZookeeperUserCount <=0 ){
keepZooKeeperWatcherAliveUntil =
System.currentTimeMillis() + keepAlive;
}
}
}
/**
* Creates a Chore thread to check the connections to master & zookeeper
* and close them when they reach their closing time (
* {@link MasterProtocolState#keepAliveUntil} and
* {@link #keepZooKeeperWatcherAliveUntil}). Keep alive time is
* managed by the release functions and the variable {@link #keepAlive}
*/
private static class DelayedClosing extends Chore implements Stoppable {
private HConnectionImplementation hci;
Stoppable stoppable;
private DelayedClosing(
HConnectionImplementation hci, Stoppable stoppable){
super(
"ZooKeeperWatcher and Master delayed closing for connection "+hci,
60*1000, // We check every minutes
stoppable);
this.hci = hci;
this.stoppable = stoppable;
}
static DelayedClosing createAndStart(HConnectionImplementation hci){
Stoppable stoppable = new Stoppable() {
private volatile boolean isStopped = false;
@Override public void stop(String why) { isStopped = true;}
@Override public boolean isStopped() {return isStopped;}
};
return new DelayedClosing(hci, stoppable);
}
protected void closeMasterProtocol(MasterProtocolState protocolState) {
if (System.currentTimeMillis() > protocolState.keepAliveUntil) {
hci.closeMasterProtocol(protocolState);
protocolState.keepAliveUntil = Long.MAX_VALUE;
}
}
@Override
protected void chore() {
synchronized (hci.masterAndZKLock) {
if (hci.canCloseZKW) {
if (System.currentTimeMillis() >
hci.keepZooKeeperWatcherAliveUntil) {
hci.closeZooKeeperWatcher();
hci.keepZooKeeperWatcherAliveUntil = Long.MAX_VALUE;
}
}
closeMasterProtocol(hci.masterAdminProtocol);
closeMasterProtocol(hci.masterMonitorProtocol);
}
}
@Override
public void stop(String why) {
stoppable.stop(why);
}
@Override
public boolean isStopped() {
return stoppable.isStopped();
}
}
private void closeZooKeeperWatcher() {
synchronized (masterAndZKLock) {
if (keepAliveZookeeper != null) {
LOG.info("Closing zookeeper sessionid=0x" +
Long.toHexString(
keepAliveZookeeper.getRecoverableZooKeeper().getSessionId()));
keepAliveZookeeper.internalClose();
keepAliveZookeeper = null;
}
keepAliveZookeeperUserCount = 0;
}
}
private static class MasterProtocolHandler implements InvocationHandler {
private HConnectionImplementation connection;
private MasterProtocolState protocolStateTracker;
protected MasterProtocolHandler(HConnectionImplementation connection,
MasterProtocolState protocolStateTracker) {
this.connection = connection;
this.protocolStateTracker = protocolStateTracker;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
if (method.getName().equals("close") &&
method.getParameterTypes().length == 0) {
release(connection, protocolStateTracker);
return null;
} else {
try {
return method.invoke(protocolStateTracker.protocol, args);
}catch (InvocationTargetException e){
// We will have this for all the exception, checked on not, sent
// by any layer, including the functional exception
Throwable cause = e.getCause();
if (cause == null){
throw new RuntimeException(
"Proxy invocation failed and getCause is null", e);
}
if (cause instanceof UndeclaredThrowableException) {
cause = cause.getCause();
}
throw cause;
}
}
}
private void release(
HConnectionImplementation connection,
MasterProtocolState target) {
connection.releaseMaster(target);
}
}
MasterProtocolState masterAdminProtocol =
new MasterProtocolState(MasterAdminProtocol.class);
MasterProtocolState masterMonitorProtocol =
new MasterProtocolState(MasterMonitorProtocol.class);
/**
* This function allows HBaseAdmin and potentially others
* to get a shared master connection.
*
* @return The shared instance. Never returns null.
* @throws MasterNotRunningException
*/
private Object getKeepAliveMasterProtocol(
MasterProtocolState protocolState, Class connectionClass)
throws MasterNotRunningException {
synchronized (masterAndZKLock) {
if (!isKeepAliveMasterConnectedAndRunning(protocolState)) {
protocolState.protocol = null;
protocolState.protocol = createMasterWithRetries(protocolState);
}
protocolState.userCount++;
protocolState.keepAliveUntil = Long.MAX_VALUE;
return Proxy.newProxyInstance(
connectionClass.getClassLoader(),
new Class[]{connectionClass},
new MasterProtocolHandler(this, protocolState)
);
}
}
@Override
public MasterAdminProtocol getMasterAdmin() throws MasterNotRunningException {
return getKeepAliveMasterAdmin();
}
@Override
public MasterMonitorProtocol getMasterMonitor() throws MasterNotRunningException {
return getKeepAliveMasterMonitor();
}
@Override
public MasterAdminKeepAliveConnection getKeepAliveMasterAdmin()
throws MasterNotRunningException {
return (MasterAdminKeepAliveConnection)
getKeepAliveMasterProtocol(masterAdminProtocol, MasterAdminKeepAliveConnection.class);
}
@Override
public void setCustomId(int customId) {
this.customId = customId;
}
@Override
public MasterMonitorKeepAliveConnection getKeepAliveMasterMonitor()
throws MasterNotRunningException {
return (MasterMonitorKeepAliveConnection)
getKeepAliveMasterProtocol(masterMonitorProtocol, MasterMonitorKeepAliveConnection.class);
}
private boolean isKeepAliveMasterConnectedAndRunning(MasterProtocolState protocolState){
if (protocolState.protocol == null){
return false;
}
try {
return protocolState.protocol.isMasterRunning(
null, RequestConverter.buildIsMasterRunningRequest()).getIsMasterRunning();
}catch (UndeclaredThrowableException e){
// It's somehow messy, but we can receive exceptions such as
// java.net.ConnectException but they're not declared. So we catch
// it...
LOG.info("Master connection is not running anymore",
e.getUndeclaredThrowable());
return false;
} catch (ServiceException se) {
LOG.warn("Checking master connection", se);
return false;
}
}
private void releaseMaster(MasterProtocolState protocolState) {
if (protocolState.protocol == null){
return;
}
synchronized (masterAndZKLock) {
--protocolState.userCount;
if (protocolState.userCount <= 0) {
protocolState.keepAliveUntil =
System.currentTimeMillis() + keepAlive;
}
}
}
private void closeMasterProtocol(MasterProtocolState protocolState) {
if (protocolState.protocol != null){
LOG.info("Closing master protocol: " + protocolState.protocolClass.getName());
protocolState.protocol = null;
}
protocolState.userCount = 0;
}
/**
* Immediate close of the shared master. Can be by the delayed close or
* when closing the connection itself.
*/
private void closeMaster() {
synchronized (masterAndZKLock) {
closeMasterProtocol(masterAdminProtocol);
closeMasterProtocol(masterMonitorProtocol);
}
}
@Override
public <T> T getRegionServerWithRetries(ServerCallable<T> callable)
throws IOException, RuntimeException {
return callable.withRetries();
}
@Override
public <T> T getRegionServerWithoutRetries(ServerCallable<T> callable)
throws IOException, RuntimeException {
return callable.withoutRetries();
}
@Deprecated
private <R> Callable<MultiResponse> createCallable(
final HRegionLocation loc, final MultiAction<R> multi,
final byte [] tableName) {
// TODO: This does not belong in here!!! St.Ack HConnections should
// not be dealing in Callables; Callables have HConnections, not other
// way around.
final HConnection connection = this;
return new Callable<MultiResponse>() {
public MultiResponse call() throws IOException {
ServerCallable<MultiResponse> callable =
new ServerCallable<MultiResponse>(connection, tableName, null) {
public MultiResponse call() throws IOException {
return ProtobufUtil.multi(server, multi);
}
@Override
public void connect(boolean reload) throws IOException {
server = connection.getClient(
loc.getHostname(), loc.getPort());
}
};
return callable.withoutRetries();
}
};
}
void updateCachedLocation(HRegionInfo hri, HRegionLocation source,
String hostname, int port, long seqNum) {
HRegionLocation newHrl = new HRegionLocation(hri, hostname, port, seqNum);
synchronized (this.cachedRegionLocations) {
cacheLocation(hri.getTableName(), source, newHrl);
}
}
/**
* Deletes the cached location of the region if necessary, based on some error from source.
* @param hri The region in question.
* @param source The source of the error that prompts us to invalidate cache.
*/
void deleteCachedLocation(HRegionInfo hri, HRegionLocation source) {
boolean isStaleDelete = false;
HRegionLocation oldLocation = null;
synchronized (this.cachedRegionLocations) {
Map<byte[], HRegionLocation> tableLocations =
getTableLocations(hri.getTableName());
oldLocation = tableLocations.get(hri.getStartKey());
if (oldLocation != null) {
// Do not delete the cache entry if it's not for the same server that gave us the error.
isStaleDelete = (source != null) && !oldLocation.equals(source);
if (!isStaleDelete) {
tableLocations.remove(hri.getStartKey());
}
}
}
if (isStaleDelete) {
LOG.debug("Received an error from " + source.getHostnamePort() + " for region "
+ hri.getRegionNameAsString() + "; not removing "
+ oldLocation.getHostnamePort() + " from cache.");
}
}
/**
* Update the location with the new value (if the exception is a RegionMovedException)
* or delete it from the cache.
* @param exception an object (to simplify user code) on which we will try to find a nested
* or wrapped or both RegionMovedException
* @param source server that is the source of the location update.
*/
private void updateCachedLocations(final byte[] tableName, Row row,
final Object exception, final HRegionLocation source) {
if (row == null || tableName == null) {
LOG.warn("Coding error, see method javadoc. row=" + (row == null ? "null" : row) +
", tableName=" + (tableName == null ? "null" : Bytes.toString(tableName)));
return;
}
// Is it something we have already updated?
final HRegionLocation oldLocation = getCachedLocation(tableName, row.getRow());
if (oldLocation == null) {
// There is no such location in the cache => it's been removed already => nothing to do
return;
}
HRegionInfo regionInfo = oldLocation.getRegionInfo();
final RegionMovedException rme = RegionMovedException.find(exception);
if (rme != null) {
LOG.info("Region " + regionInfo.getRegionNameAsString() + " moved to " +
rme.getHostname() + ":" + rme.getPort() + " according to " + source.getHostnamePort());
updateCachedLocation(
regionInfo, source, rme.getHostname(), rme.getPort(), rme.getLocationSeqNum());
} else {
deleteCachedLocation(regionInfo, source);
}
}
@Override
@Deprecated
public void processBatch(List<? extends Row> list,
final byte[] tableName,
ExecutorService pool,
Object[] results) throws IOException, InterruptedException {
// This belongs in HTable!!! Not in here. St.Ack
// results must be the same size as list
if (results.length != list.size()) {
throw new IllegalArgumentException(
"argument results must be the same size as argument list");
}
processBatchCallback(list, tableName, pool, results, null);
}
/**
* Send the queries in parallel on the different region servers. Retries on failures.
* If the method returns it means that there is no error, and the 'results' array will
* contain no exception. On error, an exception is thrown, and the 'results' array will
* contain results and exceptions.
* @deprecated since 0.96 - Use {@link HTable#processBatchCallback} instead
*/
@Override
@Deprecated
public <R> void processBatchCallback(
List<? extends Row> list,
byte[] tableName,
ExecutorService pool,
Object[] results,
Batch.Callback<R> callback)
throws IOException, InterruptedException {
Process<R> p = new Process<R>(this, list, tableName, pool, results, callback);
p.processBatchCallback();
}
/**
* Methods and attributes to manage a batch process are grouped into this single class.
* This allows, by creating a Process<R> per batch process to ensure multithread safety.
*
* This code should be move to HTable once processBatchCallback is not supported anymore in
* the HConnection interface.
*/
private static class Process<R> {
// Info on the queries and their context
private final HConnectionImplementation hci;
private final List<? extends Row> rows;
private final byte[] tableName;
private final ExecutorService pool;
private final Object[] results;
private final Batch.Callback<R> callback;
// Used during the batch process
private final List<Action<R>> toReplay;
private final LinkedList<Triple<MultiAction<R>, HRegionLocation, Future<MultiResponse>>>
inProgress;
private int curNumRetries;
// Notified when a tasks is done
private final List<MultiAction<R>> finishedTasks = new ArrayList<MultiAction<R>>();
private Process(HConnectionImplementation hci, List<? extends Row> list,
byte[] tableName, ExecutorService pool, Object[] results,
Batch.Callback<R> callback){
this.hci = hci;
this.rows = list;
this.tableName = tableName;
this.pool = pool;
this.results = results;
this.callback = callback;
this.toReplay = new ArrayList<Action<R>>();
this.inProgress =
new LinkedList<Triple<MultiAction<R>, HRegionLocation, Future<MultiResponse>>>();
this.curNumRetries = 0;
}
/**
* Group a list of actions per region servers, and send them. The created MultiActions are
* added to the inProgress list.
* @param actionsList
* @param sleepTime - sleep time before actually executing the actions. Can be zero.
* @throws IOException - if we can't locate a region after multiple retries.
*/
private void submit(List<Action<R>> actionsList, final long sleepTime) throws IOException {
// group per location => regions server
final Map<HRegionLocation, MultiAction<R>> actionsByServer =
new HashMap<HRegionLocation, MultiAction<R>>();
for (Action<R> aAction : actionsList) {
final Row row = aAction.getAction();
if (row != null) {
final HRegionLocation loc = hci.locateRegion(this.tableName, row.getRow());
if (loc == null) {
throw new IOException("No location found, aborting submit.");
}
final byte[] regionName = loc.getRegionInfo().getRegionName();
MultiAction<R> actions = actionsByServer.get(loc);
if (actions == null) {
actions = new MultiAction<R>();
actionsByServer.put(loc, actions);
}
actions.add(regionName, aAction);
}
}
// Send the queries and add them to the inProgress list
for (Entry<HRegionLocation, MultiAction<R>> e : actionsByServer.entrySet()) {
Callable<MultiResponse> callable =
createDelayedCallable(sleepTime, e.getKey(), e.getValue());
if (LOG.isTraceEnabled() && (sleepTime > 0)) {
StringBuilder sb = new StringBuilder();
for (Action<R> action : e.getValue().allActions()) {
sb.append(Bytes.toStringBinary(action.getAction().getRow()) + ";");
}
LOG.trace("Sending requests to [" + e.getKey().getHostnamePort()
+ "] with delay of [" + sleepTime + "] for rows [" + sb.toString() + "]");
}
Triple<MultiAction<R>, HRegionLocation, Future<MultiResponse>> p =
new Triple<MultiAction<R>, HRegionLocation, Future<MultiResponse>>(
e.getValue(), e.getKey(), this.pool.submit(callable));
this.inProgress.addLast(p);
}
}
/**
* Resubmit the actions which have failed, after a sleep time.
* @throws IOException
*/
private void doRetry() throws IOException{
// curNumRetries at this point is 1 or more; decrement to start from 0.
final long sleepTime = ConnectionUtils.getPauseTime(hci.pause, this.curNumRetries - 1);
submit(this.toReplay, sleepTime);
this.toReplay.clear();
}
/**
* Parameterized batch processing, allowing varying return types for
* different {@link Row} implementations.
* Throws an exception on error. If there are no exceptions, it means that the 'results'
* array is clean.
*/
private void processBatchCallback() throws IOException, InterruptedException {
if (this.results.length != this.rows.size()) {
throw new IllegalArgumentException(
"argument results (size="+results.length+") must be the same size as " +
"argument list (size="+this.rows.size()+")");
}
if (this.rows.isEmpty()) {
return;
}
boolean isTraceEnabled = LOG.isTraceEnabled();
BatchErrors errors = new BatchErrors();
BatchErrors retriedErrors = null;
if (isTraceEnabled) {
retriedErrors = new BatchErrors();
}
// We keep the number of retry per action.
int[] nbRetries = new int[this.results.length];
// Build the action list. This list won't change after being created, hence the
// indexes will remain constant, allowing a direct lookup.
final List<Action<R>> listActions = new ArrayList<Action<R>>(this.rows.size());
for (int i = 0; i < this.rows.size(); i++) {
Action<R> action = new Action<R>(this.rows.get(i), i);
listActions.add(action);
}
// execute the actions. We will analyze and resubmit the actions in a 'while' loop.
submit(listActions, 0);
// LastRetry is true if, either:
// we had an exception 'DoNotRetry'
// we had more than numRetries for any action
// In this case, we will finish the current retries but we won't start new ones.
boolean lastRetry = false;
// despite its name numRetries means number of tries. So if numRetries == 1 it means we
// won't retry. And we compare vs. 2 in case someone set it to zero.
boolean noRetry = (hci.numRetries < 2);
// Analyze and resubmit until all actions are done successfully or failed after numRetries
while (!this.inProgress.isEmpty()) {
// We need the original multi action to find out what actions to replay if
// we have a 'total' failure of the Future<MultiResponse>
// We need the HRegionLocation as we give it back if we go out of retries
Triple<MultiAction<R>, HRegionLocation, Future<MultiResponse>> currentTask =
removeFirstDone();
// Get the answer, keep the exception if any as we will use it for the analysis
MultiResponse responses = null;
ExecutionException exception = null;
try {
responses = currentTask.getThird().get();
} catch (ExecutionException e) {
exception = e;
}
// Error case: no result at all for this multi action. We need to redo all actions
if (responses == null) {
for (List<Action<R>> actions : currentTask.getFirst().actions.values()) {
for (Action<R> action : actions) {
Row row = action.getAction();
hci.updateCachedLocations(tableName, row, exception, currentTask.getSecond());
if (noRetry) {
errors.add(exception, row, currentTask);
} else {
if (isTraceEnabled) {
retriedErrors.add(exception, row, currentTask);
}
lastRetry = addToReplay(nbRetries, action);
}
}
}
} else { // Success or partial success
// Analyze detailed results. We can still have individual failures to be redo.
// two specific exceptions are managed:
// - DoNotRetryIOException: we continue to retry for other actions
// - RegionMovedException: we update the cache with the new region location
for (Entry<byte[], List<Pair<Integer, Object>>> resultsForRS :
responses.getResults().entrySet()) {
for (Pair<Integer, Object> regionResult : resultsForRS.getValue()) {
Action<R> correspondingAction = listActions.get(regionResult.getFirst());
Object result = regionResult.getSecond();
this.results[correspondingAction.getOriginalIndex()] = result;
// Failure: retry if it's make sense else update the errors lists
if (result == null || result instanceof Throwable) {
Row row = correspondingAction.getAction();
hci.updateCachedLocations(this.tableName, row, result, currentTask.getSecond());
if (result instanceof DoNotRetryIOException || noRetry) {
errors.add((Exception)result, row, currentTask);
} else {
if (isTraceEnabled) {
retriedErrors.add((Exception)result, row, currentTask);
}
lastRetry = addToReplay(nbRetries, correspondingAction);
}
} else // success
if (callback != null) {
this.callback.update(resultsForRS.getKey(),
this.rows.get(regionResult.getFirst()).getRow(),
(R) result);
}
}
}
}
// Retry all actions in toReplay then clear it.
if (!noRetry && !toReplay.isEmpty()) {
if (isTraceEnabled) {
LOG.trace("Retrying due to errors: " + retriedErrors.getDescriptionAndClear());
}
doRetry();
if (lastRetry) {
if (isTraceEnabled) {
LOG.trace("No more retries");
}
noRetry = true;
}
}
}
errors.rethrowIfAny();
}
private class BatchErrors {
private List<Throwable> exceptions = new ArrayList<Throwable>();
private List<Row> actions = new ArrayList<Row>();
private List<String> addresses = new ArrayList<String>();
public void add(Exception ex, Row row,
Triple<MultiAction<R>, HRegionLocation, Future<MultiResponse>> obj) {
exceptions.add(ex);
actions.add(row);
addresses.add(obj.getSecond().getHostnamePort());
}
public void rethrowIfAny() throws RetriesExhaustedWithDetailsException {
if (!exceptions.isEmpty()) {
throw makeException();
}
}
public String getDescriptionAndClear()
{
if (exceptions.isEmpty()) {
return "";
}
String result = makeException().getMessage();
exceptions.clear();
actions.clear();
addresses.clear();
return result;
};
private RetriesExhaustedWithDetailsException makeException() {
return new RetriesExhaustedWithDetailsException(exceptions, actions, addresses);
}
}
/**
* Put the action that has to be retried in the Replay list.
* @return true if we're out of numRetries and it's the last retry.
*/
private boolean addToReplay(int[] nbRetries, Action<R> action) {
this.toReplay.add(action);
nbRetries[action.getOriginalIndex()]++;
if (nbRetries[action.getOriginalIndex()] > this.curNumRetries) {
this.curNumRetries = nbRetries[action.getOriginalIndex()];
}
// numRetries means number of tries, while curNumRetries means current number of retries. So
// we need to add 1 to make them comparable. And as we look for the last try we compare
// with '>=' and no '>'. And we need curNumRetries to means what it says as we don't want
// to initialize it to 1.
return ( (this.curNumRetries +1) >= hci.numRetries);
}
/**
* Wait for one of tasks to be done, and remove it from the list.
* @return the tasks done.
*/
private Triple<MultiAction<R>, HRegionLocation, Future<MultiResponse>>
removeFirstDone() throws InterruptedException {
while (true) {
synchronized (finishedTasks) {
if (!finishedTasks.isEmpty()) {
MultiAction<R> done = finishedTasks.remove(finishedTasks.size() - 1);
// We now need to remove it from the inProgress part.
Iterator<Triple<MultiAction<R>, HRegionLocation, Future<MultiResponse>>> it =
inProgress.iterator();
while (it.hasNext()) {
Triple<MultiAction<R>, HRegionLocation, Future<MultiResponse>> task = it.next();
if (task.getFirst() == done) { // We have the exact object. No java equals here.
it.remove();
return task;
}
}
LOG.error("Development error: We didn't see a task in the list. " +
done.getRegions());
}
finishedTasks.wait(10);
}
}
}
private Callable<MultiResponse> createDelayedCallable(
final long delay, final HRegionLocation loc, final MultiAction<R> multi) {
final Callable<MultiResponse> delegate = hci.createCallable(loc, multi, tableName);
return new Callable<MultiResponse>() {
private final long creationTime = System.currentTimeMillis();
@Override
public MultiResponse call() throws Exception {
try {
final long waitingTime = delay + creationTime - System.currentTimeMillis();
if (waitingTime > 0) {
Thread.sleep(waitingTime);
}
return delegate.call();
} finally {
synchronized (finishedTasks) {
finishedTasks.add(multi);
finishedTasks.notifyAll();
}
}
}
};
}
}
/*
* Return the number of cached region for a table. It will only be called
* from a unit test.
*/
int getNumberOfCachedRegionLocations(final byte[] tableName) {
Integer key = Bytes.mapKey(tableName);
synchronized (this.cachedRegionLocations) {
Map<byte[], HRegionLocation> tableLocs =
this.cachedRegionLocations.get(key);
if (tableLocs == null) {
return 0;
}
return tableLocs.values().size();
}
}
/**
* Check the region cache to see whether a region is cached yet or not.
* Called by unit tests.
* @param tableName tableName
* @param row row
* @return Region cached or not.
*/
boolean isRegionCached(final byte[] tableName, final byte[] row) {
HRegionLocation location = getCachedLocation(tableName, row);
return location != null;
}
@Override
public void setRegionCachePrefetch(final byte[] tableName,
final boolean enable) {
if (!enable) {
regionCachePrefetchDisabledTables.add(Bytes.mapKey(tableName));
}
else {
regionCachePrefetchDisabledTables.remove(Bytes.mapKey(tableName));
}
}
@Override
public boolean getRegionCachePrefetch(final byte[] tableName) {
return !regionCachePrefetchDisabledTables.contains(Bytes.mapKey(tableName));
}
@Override
public void abort(final String msg, Throwable t) {
if (t instanceof KeeperException.SessionExpiredException
&& keepAliveZookeeper != null) {
synchronized (masterAndZKLock) {
if (keepAliveZookeeper != null) {
LOG.warn("This client just lost it's session with ZooKeeper," +
" closing it." +
" It will be recreated next time someone needs it", t);
closeZooKeeperWatcher();
}
}
} else {
if (t != null) {
LOG.fatal(msg, t);
} else {
LOG.fatal(msg);
}
this.aborted = true;
close();
this.closed = true;
}
}
@Override
public boolean isClosed() {
return this.closed;
}
@Override
public boolean isAborted(){
return this.aborted;
}
@Override
public int getCurrentNrHRS() throws IOException {
ZooKeeperKeepAliveConnection zkw = getKeepAliveZooKeeperWatcher();
try {
// We go to zk rather than to master to get count of regions to avoid
// HTable having a Master dependency. See HBase-2828
return ZKUtil.getNumberOfChildren(zkw, zkw.rsZNode);
} catch (KeeperException ke) {
throw new IOException("Unexpected ZooKeeper exception", ke);
} finally {
zkw.close();
}
}
/**
* Increment this client's reference count.
*/
void incCount() {
++refCount;
}
/**
* Decrement this client's reference count.
*/
void decCount() {
if (refCount > 0) {
--refCount;
}
}
/**
* Return if this client has no reference
*
* @return true if this client has no reference; false otherwise
*/
boolean isZeroReference() {
return refCount == 0;
}
void internalClose() {
if (this.closed) {
return;
}
delayedClosing.stop("Closing connection");
closeMaster();
closeZooKeeperWatcher();
this.servers.clear();
this.rpcEngine.close();
this.closed = true;
}
@Override
public void close() {
if (managed) {
if (aborted) {
HConnectionManager.deleteStaleConnection(this);
} else {
HConnectionManager.deleteConnection(this, false);
}
} else {
internalClose();
}
}
/**
* Close the connection for good, regardless of what the current value of
* {@link #refCount} is. Ideally, {@link #refCount} should be zero at this
* point, which would be the case if all of its consumers close the
* connection. However, on the off chance that someone is unable to close
* the connection, perhaps because it bailed out prematurely, the method
* below will ensure that this {@link HConnection} instance is cleaned up.
* Caveat: The JVM may take an unknown amount of time to call finalize on an
* unreachable object, so our hope is that every consumer cleans up after
* itself, like any good citizen.
*/
@Override
protected void finalize() throws Throwable {
super.finalize();
// Pretend as if we are about to release the last remaining reference
refCount = 1;
close();
}
@Override
public HTableDescriptor[] listTables() throws IOException {
MasterMonitorKeepAliveConnection master = getKeepAliveMasterMonitor();
try {
GetTableDescriptorsRequest req =
RequestConverter.buildGetTableDescriptorsRequest(null);
return ProtobufUtil.getHTableDescriptorArray(master.getTableDescriptors(null, req));
} catch (ServiceException se) {
throw ProtobufUtil.getRemoteException(se);
} finally {
master.close();
}
}
@Override
public HTableDescriptor[] getHTableDescriptors(List<String> tableNames) throws IOException {
if (tableNames == null || tableNames.isEmpty()) return new HTableDescriptor[0];
MasterMonitorKeepAliveConnection master = getKeepAliveMasterMonitor();
try {
GetTableDescriptorsRequest req =
RequestConverter.buildGetTableDescriptorsRequest(tableNames);
return ProtobufUtil.getHTableDescriptorArray(master.getTableDescriptors(null, req));
} catch (ServiceException se) {
throw ProtobufUtil.getRemoteException(se);
} finally {
master.close();
}
}
/**
* Connects to the master to get the table descriptor.
* @param tableName table name
* @return
* @throws IOException if the connection to master fails or if the table
* is not found.
*/
@Override
public HTableDescriptor getHTableDescriptor(final byte[] tableName)
throws IOException {
if (tableName == null || tableName.length == 0) return null;
if (Bytes.equals(tableName, HConstants.ROOT_TABLE_NAME)) {
return new UnmodifyableHTableDescriptor(HTableDescriptor.ROOT_TABLEDESC);
}
if (Bytes.equals(tableName, HConstants.META_TABLE_NAME)) {
return HTableDescriptor.META_TABLEDESC;
}
MasterMonitorKeepAliveConnection master = getKeepAliveMasterMonitor();
GetTableDescriptorsResponse htds;
try {
GetTableDescriptorsRequest req =
RequestConverter.buildGetTableDescriptorsRequest(null);
htds = master.getTableDescriptors(null, req);
} catch (ServiceException se) {
throw ProtobufUtil.getRemoteException(se);
} finally {
master.close();
}
for (TableSchema ts : htds.getTableSchemaList()) {
if (Bytes.equals(tableName, ts.getName().toByteArray())) {
return HTableDescriptor.convert(ts);
}
}
throw new TableNotFoundException(Bytes.toString(tableName));
}
/**
* Override the RpcClientEngine implementation used by this connection.
* <strong>FOR TESTING PURPOSES ONLY!</strong>
*/
void setRpcEngine(RpcClientEngine engine) {
this.rpcEngine = engine;
}
}
/**
* Set the number of retries to use serverside when trying to communicate
* with another server over {@link HConnection}. Used updating catalog
* tables, etc. Call this method before we create any Connections.
* @param c The Configuration instance to set the retries into.
* @param log Used to log what we set in here.
*/
public static void setServerSideHConnectionRetries(final Configuration c,
final Log log) {
int hcRetries = c.getInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER,
HConstants.DEFAULT_HBASE_CLIENT_RETRIES_NUMBER);
// Go big. Multiply by 10. If we can't get to meta after this many retries
// then something seriously wrong.
int serversideMultiplier =
c.getInt("hbase.client.serverside.retries.multiplier", 10);
int retries = hcRetries * serversideMultiplier;
c.setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, retries);
log.debug("HConnection retries=" + retries);
}
}