/**
* Copyright 2011 The Apache Software Foundation
*
* 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.master;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import javax.management.ObjectName;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Chore;
import org.apache.hadoop.hbase.ClusterStatus;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HServerLoad;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.Server;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.TableDescriptors;
import org.apache.hadoop.hbase.TableNotDisabledException;
import org.apache.hadoop.hbase.TableNotFoundException;
import org.apache.hadoop.hbase.UnknownRegionException;
import org.apache.hadoop.hbase.catalog.CatalogTracker;
import org.apache.hadoop.hbase.catalog.MetaReader;
import org.apache.hadoop.hbase.client.HConnectionManager;
import org.apache.hadoop.hbase.client.MetaScanner;
import org.apache.hadoop.hbase.client.MetaScanner.MetaScannerVisitor;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
import org.apache.hadoop.hbase.executor.ExecutorService;
import org.apache.hadoop.hbase.executor.ExecutorService.ExecutorType;
import org.apache.hadoop.hbase.ipc.HBaseRPC;
import org.apache.hadoop.hbase.ipc.HBaseServer;
import org.apache.hadoop.hbase.ipc.HMasterInterface;
import org.apache.hadoop.hbase.ipc.HMasterRegionInterface;
import org.apache.hadoop.hbase.ipc.ProtocolSignature;
import org.apache.hadoop.hbase.ipc.RpcServer;
import org.apache.hadoop.hbase.master.handler.CreateTableHandler;
import org.apache.hadoop.hbase.master.handler.DeleteTableHandler;
import org.apache.hadoop.hbase.master.handler.DisableTableHandler;
import org.apache.hadoop.hbase.master.handler.EnableTableHandler;
import org.apache.hadoop.hbase.master.handler.ModifyTableHandler;
import org.apache.hadoop.hbase.master.handler.ServerShutdownHandler;
import org.apache.hadoop.hbase.master.handler.TableAddFamilyHandler;
import org.apache.hadoop.hbase.master.handler.TableDeleteFamilyHandler;
import org.apache.hadoop.hbase.master.handler.TableModifyFamilyHandler;
import org.apache.hadoop.hbase.master.metrics.MasterMetrics;
import org.apache.hadoop.hbase.monitoring.MemoryBoundedLogMessageBuffer;
import org.apache.hadoop.hbase.monitoring.MonitoredTask;
import org.apache.hadoop.hbase.monitoring.TaskMonitor;
import org.apache.hadoop.hbase.replication.regionserver.Replication;
import org.apache.hadoop.hbase.security.User;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.FSTableDescriptors;
import org.apache.hadoop.hbase.util.HasThread;
import org.apache.hadoop.hbase.util.InfoServer;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.hadoop.hbase.util.Sleeper;
import org.apache.hadoop.hbase.util.Threads;
import org.apache.hadoop.hbase.util.VersionInfo;
import org.apache.hadoop.hbase.zookeeper.ClusterId;
import org.apache.hadoop.hbase.zookeeper.ClusterStatusTracker;
import org.apache.hadoop.hbase.zookeeper.DrainingServerTracker;
import org.apache.hadoop.hbase.zookeeper.RegionServerTracker;
import org.apache.hadoop.hbase.zookeeper.ZKUtil;
import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
import org.apache.hadoop.io.MapWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.metrics.util.MBeanUtil;
import org.apache.hadoop.net.DNS;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.Watcher;
/**
* HMaster is the "master server" for HBase. An HBase cluster has one active
* master. If many masters are started, all compete. Whichever wins goes on to
* run the cluster. All others park themselves in their constructor until
* master or cluster shutdown or until the active master loses its lease in
* zookeeper. Thereafter, all running master jostle to take over master role.
*
* <p>The Master can be asked shutdown the cluster. See {@link #shutdown()}. In
* this case it will tell all regionservers to go down and then wait on them
* all reporting in that they are down. This master will then shut itself down.
*
* <p>You can also shutdown just this master. Call {@link #stopMaster()}.
*
* @see HMasterInterface
* @see HMasterRegionInterface
* @see Watcher
*/
public class HMaster extends HasThread
implements HMasterInterface, HMasterRegionInterface, MasterServices,
Server {
private static final Log LOG = LogFactory.getLog(HMaster.class.getName());
// MASTER is name of the webapp and the attribute name used stuffing this
//instance into web context.
public static final String MASTER = "master";
// The configuration for the Master
private final Configuration conf;
// server for the web ui
private InfoServer infoServer;
// Our zk client.
private ZooKeeperWatcher zooKeeper;
// Manager and zk listener for master election
private ActiveMasterManager activeMasterManager;
// Region server tracker
private RegionServerTracker regionServerTracker;
// Draining region server tracker
private DrainingServerTracker drainingServerTracker;
// RPC server for the HMaster
private final RpcServer rpcServer;
/**
* This servers address.
*/
private final InetSocketAddress isa;
// Metrics for the HMaster
private final MasterMetrics metrics;
// file system manager for the master FS operations
private MasterFileSystem fileSystemManager;
// server manager to deal with region server info
private ServerManager serverManager;
// manager of assignment nodes in zookeeper
AssignmentManager assignmentManager;
// manager of catalog regions
private CatalogTracker catalogTracker;
// Cluster status zk tracker and local setter
private ClusterStatusTracker clusterStatusTracker;
// buffer for "fatal error" notices from region servers
// in the cluster. This is only used for assisting
// operations/debugging.
private MemoryBoundedLogMessageBuffer rsFatals;
// This flag is for stopping this Master instance. Its set when we are
// stopping or aborting
private volatile boolean stopped = false;
// Set on abort -- usually failure of our zk session.
private volatile boolean abort = false;
// flag set after we become the active master (used for testing)
private volatile boolean isActiveMaster = false;
// flag set after we complete initialization once active (used for testing)
private volatile boolean initialized = false;
// Instance of the hbase executor service.
ExecutorService executorService;
private LoadBalancer balancer;
private Thread balancerChore;
// If 'true', the balancer is 'on'. If 'false', the balancer will not run.
private volatile boolean balanceSwitch = true;
private CatalogJanitor catalogJanitorChore;
private LogCleaner logCleaner;
private MasterCoprocessorHost cpHost;
private final ServerName serverName;
private TableDescriptors tableDescriptors;
// Time stamps for when a hmaster was started and when it became active
private long masterStartTime;
private long masterActiveTime;
/**
* MX Bean for MasterInfo
*/
private ObjectName mxBean = null;
/**
* Initializes the HMaster. The steps are as follows:
* <p>
* <ol>
* <li>Initialize HMaster RPC and address
* <li>Connect to ZooKeeper.
* </ol>
* <p>
* Remaining steps of initialization occur in {@link #run()} so that they
* run in their own thread rather than within the context of the constructor.
* @throws InterruptedException
*/
public HMaster(final Configuration conf)
throws IOException, KeeperException, InterruptedException {
this.conf = new Configuration(conf);
// Disable the block cache on the master
this.conf.setFloat(HConstants.HFILE_BLOCK_CACHE_SIZE_KEY, 0.0f);
// Set how many times to retry talking to another server over HConnection.
HConnectionManager.setServerSideHConnectionRetries(this.conf, LOG);
// Server to handle client requests.
String hostname = DNS.getDefaultHost(
conf.get("hbase.master.dns.interface", "default"),
conf.get("hbase.master.dns.nameserver", "default"));
int port = conf.getInt(HConstants.MASTER_PORT, HConstants.DEFAULT_MASTER_PORT);
// Creation of a HSA will force a resolve.
InetSocketAddress initialIsa = new InetSocketAddress(hostname, port);
if (initialIsa.getAddress() == null) {
throw new IllegalArgumentException("Failed resolve of " + this.isa);
}
int numHandlers = conf.getInt("hbase.master.handler.count",
conf.getInt("hbase.regionserver.handler.count", 25));
this.rpcServer = HBaseRPC.getServer(this,
new Class<?>[]{HMasterInterface.class, HMasterRegionInterface.class},
initialIsa.getHostName(), // BindAddress is IP we got for this server.
initialIsa.getPort(),
numHandlers,
0, // we dont use high priority handlers in master
conf.getBoolean("hbase.rpc.verbose", false), conf,
0); // this is a DNC w/o high priority handlers
// Set our address.
this.isa = this.rpcServer.getListenerAddress();
this.serverName = new ServerName(this.isa.getHostName(),
this.isa.getPort(), System.currentTimeMillis());
this.rsFatals = new MemoryBoundedLogMessageBuffer(
conf.getLong("hbase.master.buffer.for.rs.fatals", 1*1024*1024));
// initialize server principal (if using secure Hadoop)
User.login(conf, "hbase.master.keytab.file",
"hbase.master.kerberos.principal", this.isa.getHostName());
// set the thread name now we have an address
setName(MASTER + "-" + this.serverName.toString());
Replication.decorateMasterConfiguration(this.conf);
// Hack! Maps DFSClient => Master for logs. HDFS made this
// config param for task trackers, but we can piggyback off of it.
if (this.conf.get("mapred.task.id") == null) {
this.conf.set("mapred.task.id", "hb_m_" + this.serverName.toString());
}
this.zooKeeper = new ZooKeeperWatcher(conf, MASTER + ":" + isa.getPort(), this, true);
this.rpcServer.startThreads();
this.metrics = new MasterMetrics(getServerName().toString());
}
/**
* Stall startup if we are designated a backup master; i.e. we want someone
* else to become the master before proceeding.
* @param c
* @param amm
* @throws InterruptedException
*/
private static void stallIfBackupMaster(final Configuration c,
final ActiveMasterManager amm)
throws InterruptedException {
// If we're a backup master, stall until a primary to writes his address
if (!c.getBoolean(HConstants.MASTER_TYPE_BACKUP,
HConstants.DEFAULT_MASTER_TYPE_BACKUP)) {
return;
}
LOG.debug("HMaster started in backup mode. " +
"Stalling until master znode is written.");
// This will only be a minute or so while the cluster starts up,
// so don't worry about setting watches on the parent znode
while (!amm.isActiveMaster()) {
LOG.debug("Waiting for master address ZNode to be written " +
"(Also watching cluster state node)");
Thread.sleep(c.getInt("zookeeper.session.timeout", 180 * 1000));
}
}
/**
* Main processing loop for the HMaster.
* <ol>
* <li>Block until becoming active master
* <li>Finish initialization via finishInitialization(MonitoredTask)
* <li>Enter loop until we are stopped
* <li>Stop services and perform cleanup once stopped
* </ol>
*/
@Override
public void run() {
MonitoredTask startupStatus =
TaskMonitor.get().createStatus("Master startup");
startupStatus.setDescription("Master startup");
masterStartTime = System.currentTimeMillis();
try {
/*
* Block on becoming the active master.
*
* We race with other masters to write our address into ZooKeeper. If we
* succeed, we are the primary/active master and finish initialization.
*
* If we do not succeed, there is another active master and we should
* now wait until it dies to try and become the next active master. If we
* do not succeed on our first attempt, this is no longer a cluster startup.
*/
becomeActiveMaster(startupStatus);
// We are either the active master or we were asked to shutdown
if (!this.stopped) {
finishInitialization(startupStatus);
loop();
}
} catch (Throwable t) {
abort("Unhandled exception. Starting shutdown.", t);
} finally {
startupStatus.cleanup();
stopChores();
// Wait for all the remaining region servers to report in IFF we were
// running a cluster shutdown AND we were NOT aborting.
if (!this.abort && this.serverManager != null &&
this.serverManager.isClusterShutdown()) {
this.serverManager.letRegionServersShutdown();
}
stopServiceThreads();
// Stop services started for both backup and active masters
if (this.activeMasterManager != null) this.activeMasterManager.stop();
if (this.catalogTracker != null) this.catalogTracker.stop();
if (this.serverManager != null) this.serverManager.stop();
if (this.assignmentManager != null) this.assignmentManager.stop();
if (this.fileSystemManager != null) this.fileSystemManager.stop();
this.zooKeeper.close();
}
LOG.info("HMaster main thread exiting");
}
/**
* Try becoming active master.
* @param startupStatus
* @return True if we could successfully become the active master.
* @throws InterruptedException
*/
private boolean becomeActiveMaster(MonitoredTask startupStatus)
throws InterruptedException {
// TODO: This is wrong!!!! Should have new servername if we restart ourselves,
// if we come back to life.
this.activeMasterManager = new ActiveMasterManager(zooKeeper, this.serverName,
this);
this.zooKeeper.registerListener(activeMasterManager);
stallIfBackupMaster(this.conf, this.activeMasterManager);
return this.activeMasterManager.blockUntilBecomingActiveMaster(startupStatus);
}
/**
* Initialize all ZK based system trackers.
* @throws IOException
* @throws InterruptedException
*/
private void initializeZKBasedSystemTrackers() throws IOException,
InterruptedException, KeeperException {
this.catalogTracker = new CatalogTracker(this.zooKeeper, this.conf,
this, conf.getInt("hbase.master.catalog.timeout", Integer.MAX_VALUE));
this.catalogTracker.start();
this.assignmentManager = new AssignmentManager(this, serverManager,
this.catalogTracker, this.executorService);
this.balancer = LoadBalancerFactory.getLoadBalancer(conf);
zooKeeper.registerListenerFirst(assignmentManager);
this.regionServerTracker = new RegionServerTracker(zooKeeper, this,
this.serverManager);
this.regionServerTracker.start();
this.drainingServerTracker = new DrainingServerTracker(zooKeeper, this,
this.serverManager);
this.drainingServerTracker.start();
// Set the cluster as up. If new RSs, they'll be waiting on this before
// going ahead with their startup.
this.clusterStatusTracker = new ClusterStatusTracker(getZooKeeper(), this);
this.clusterStatusTracker.start();
boolean wasUp = this.clusterStatusTracker.isClusterUp();
if (!wasUp) this.clusterStatusTracker.setClusterUp();
LOG.info("Server active/primary master; " + this.serverName +
", sessionid=0x" +
Long.toHexString(this.zooKeeper.getRecoverableZooKeeper().getSessionId()) +
", cluster-up flag was=" + wasUp);
}
private void loop() {
// Check if we should stop every second.
Sleeper sleeper = new Sleeper(1000, this);
while (!this.stopped) {
sleeper.sleep();
}
}
/**
* Finish initialization of HMaster after becoming the primary master.
*
* <ol>
* <li>Initialize master components - file system manager, server manager,
* assignment manager, region server tracker, catalog tracker, etc</li>
* <li>Start necessary service threads - rpc server, info server,
* executor services, etc</li>
* <li>Set cluster as UP in ZooKeeper</li>
* <li>Wait for RegionServers to check-in</li>
* <li>Split logs and perform data recovery, if necessary</li>
* <li>Ensure assignment of root and meta regions<li>
* <li>Handle either fresh cluster start or master failover</li>
* </ol>
*
* @throws IOException
* @throws InterruptedException
* @throws KeeperException
*/
private void finishInitialization(MonitoredTask status)
throws IOException, InterruptedException, KeeperException {
isActiveMaster = true;
/*
* We are active master now... go initialize components we need to run.
* Note, there may be dross in zk from previous runs; it'll get addressed
* below after we determine if cluster startup or failover.
*/
status.setStatus("Initializing Master file system");
this.masterActiveTime = System.currentTimeMillis();
// TODO: Do this using Dependency Injection, using PicoContainer, Guice or Spring.
this.fileSystemManager = new MasterFileSystem(this, this, metrics);
this.tableDescriptors =
new FSTableDescriptors(this.fileSystemManager.getFileSystem(),
this.fileSystemManager.getRootDir());
// publish cluster ID
status.setStatus("Publishing Cluster ID in ZooKeeper");
ClusterId.setClusterId(this.zooKeeper, fileSystemManager.getClusterId());
this.executorService = new ExecutorService(getServerName().toString());
this.serverManager = new ServerManager(this, this);
status.setStatus("Initializing ZK system trackers");
initializeZKBasedSystemTrackers();
// initialize master side coprocessors before we start handling requests
status.setStatus("Initializing master coprocessors");
this.cpHost = new MasterCoprocessorHost(this, this.conf);
// start up all service threads.
status.setStatus("Initializing master service threads");
startServiceThreads();
// Wait for region servers to report in.
this.serverManager.waitForRegionServers(status);
// Check zk for regionservers that are up but didn't register
for (ServerName sn: this.regionServerTracker.getOnlineServers()) {
if (!this.serverManager.isServerOnline(sn)) {
// Not registered; add it.
LOG.info("Registering server found up in zk but who has not yet " +
"reported in: " + sn);
this.serverManager.recordNewServer(sn, HServerLoad.EMPTY_HSERVERLOAD);
}
}
// TODO: Should do this in background rather than block master startup
status.setStatus("Splitting logs after master startup");
this.fileSystemManager.
splitLogAfterStartup(this.serverManager.getOnlineServers().keySet());
// Make sure root and meta assigned before proceeding.
assignRootAndMeta(status);
// Update meta with new HRI if required. i.e migrate all HRI with HTD to
// HRI with out HTD in meta and update the status in ROOT. This must happen
// before we assign all user regions or else the assignment will fail.
// TODO: Remove this when we do 0.94.
org.apache.hadoop.hbase.catalog.MetaMigrationRemovingHTD.
updateMetaWithNewHRI(this);
// Fixup assignment manager status
status.setStatus("Starting assignment manager");
this.assignmentManager.joinCluster();
this.balancer.setClusterStatus(getClusterStatus());
this.balancer.setMasterServices(this);
// Fixing up missing daughters if any
status.setStatus("Fixing up missing daughters");
fixupDaughters(status);
// Start balancer and meta catalog janitor after meta and regions have
// been assigned.
status.setStatus("Starting balancer and catalog janitor");
this.balancerChore = getAndStartBalancerChore(this);
this.catalogJanitorChore = new CatalogJanitor(this, this);
Threads.setDaemonThreadRunning(catalogJanitorChore.getThread());
registerMBean();
status.markComplete("Initialization successful");
LOG.info("Master has completed initialization");
initialized = true;
if (this.cpHost != null) {
// don't let cp initialization errors kill the master
try {
this.cpHost.postStartMaster();
} catch (IOException ioe) {
LOG.error("Coprocessor postStartMaster() hook failed", ioe);
}
}
}
/**
* Check <code>-ROOT-</code> and <code>.META.</code> are assigned. If not,
* assign them.
* @throws InterruptedException
* @throws IOException
* @throws KeeperException
* @return Count of regions we assigned.
*/
int assignRootAndMeta(MonitoredTask status)
throws InterruptedException, IOException, KeeperException {
int assigned = 0;
long timeout = this.conf.getLong("hbase.catalog.verification.timeout", 1000);
// Work on ROOT region. Is it in zk in transition?
status.setStatus("Assigning ROOT region");
boolean rit = this.assignmentManager.
processRegionInTransitionAndBlockUntilAssigned(HRegionInfo.ROOT_REGIONINFO);
ServerName expiredServer = null;
if (!catalogTracker.verifyRootRegionLocation(timeout)) {
ServerName currentRootServer = this.catalogTracker.getRootLocation();
if (expireIfOnline(currentRootServer)) {
// We are expiring this server. The processing of expiration will assign
// root so don't do it here.
expiredServer = currentRootServer;
} else {
// Root was not on an online server when we failed verification
this.assignmentManager.assignRoot();
}
this.catalogTracker.waitForRoot();
//This guarantees that the transition has completed
this.assignmentManager.waitForAssignment(HRegionInfo.ROOT_REGIONINFO);
assigned++;
} else {
// Region already assigned. We didn't assign it. Add to in-memory state.
this.assignmentManager.regionOnline(HRegionInfo.ROOT_REGIONINFO,
this.catalogTracker.getRootLocation());
}
LOG.info("-ROOT- assigned=" + assigned + ", rit=" + rit +
", location=" + catalogTracker.getRootLocation());
// Work on meta region
status.setStatus("Assigning META region");
rit = this.assignmentManager.
processRegionInTransitionAndBlockUntilAssigned(HRegionInfo.FIRST_META_REGIONINFO);
if (!this.catalogTracker.verifyMetaRegionLocation(timeout)) {
ServerName currentMetaServer =
this.catalogTracker.getMetaLocationOrReadLocationFromRoot();
if (currentMetaServer != null && currentMetaServer.equals(expiredServer)) {
// We are expiring the server that is carrying meta already.
// The expiration processing will take care of reassigning meta.
expireIfOnline(currentMetaServer);
} else {
this.assignmentManager.assignMeta();
}
this.catalogTracker.waitForMeta();
// Above check waits for general meta availability but this does not
// guarantee that the transition has completed
this.assignmentManager.waitForAssignment(HRegionInfo.FIRST_META_REGIONINFO);
assigned++;
} else {
// Region already assigned. We didnt' assign it. Add to in-memory state.
this.assignmentManager.regionOnline(HRegionInfo.FIRST_META_REGIONINFO,
this.catalogTracker.getMetaLocation());
}
LOG.info(".META. assigned=" + assigned + ", rit=" + rit +
", location=" + catalogTracker.getMetaLocation());
status.setStatus("META and ROOT assigned.");
return assigned;
}
void fixupDaughters(final MonitoredTask status) throws IOException {
final Map<HRegionInfo, Result> offlineSplitParents =
new HashMap<HRegionInfo, Result>();
// This visitor collects offline split parents in the .META. table
MetaReader.Visitor visitor = new MetaReader.Visitor() {
@Override
public boolean visit(Result r) throws IOException {
if (r == null || r.isEmpty()) return true;
HRegionInfo info =
MetaReader.parseHRegionInfoFromCatalogResult(
r, HConstants.REGIONINFO_QUALIFIER);
if (info == null) return true; // Keep scanning
if (info.isOffline() && info.isSplit()) {
offlineSplitParents.put(info, r);
}
// Returning true means "keep scanning"
return true;
}
};
// Run full scan of .META. catalog table passing in our custom visitor
MetaReader.fullScan(this.catalogTracker, visitor);
// Now work on our list of found parents. See if any we can clean up.
int fixups = 0;
for (Map.Entry<HRegionInfo, Result> e : offlineSplitParents.entrySet()) {
fixups += ServerShutdownHandler.fixupDaughters(
e.getValue(), assignmentManager, catalogTracker);
}
if (fixups != 0) {
LOG.info("Scanned the catalog and fixed up " + fixups +
" missing daughter region(s)");
}
}
/**
* Expire a server if we find it is one of the online servers set.
* @param sn ServerName to check.
* @return True if server was online and so we expired it as unreachable.
*/
private boolean expireIfOnline(final ServerName sn) {
if (sn == null) return false;
if (!this.serverManager.isServerOnline(sn)) return false;
LOG.info("Forcing expiration of " + sn);
this.serverManager.expireServer(sn);
return true;
}
@Override
public ProtocolSignature getProtocolSignature(
String protocol, long version, int clientMethodsHashCode)
throws IOException {
if (HMasterInterface.class.getName().equals(protocol)) {
return new ProtocolSignature(HMasterInterface.VERSION, null);
} else if (HMasterRegionInterface.class.getName().equals(protocol)) {
return new ProtocolSignature(HMasterRegionInterface.VERSION, null);
}
throw new IOException("Unknown protocol: " + protocol);
}
public long getProtocolVersion(String protocol, long clientVersion) {
if (HMasterInterface.class.getName().equals(protocol)) {
return HMasterInterface.VERSION;
} else if (HMasterRegionInterface.class.getName().equals(protocol)) {
return HMasterRegionInterface.VERSION;
}
// unknown protocol
LOG.warn("Version requested for unimplemented protocol: "+protocol);
return -1;
}
@Override
public TableDescriptors getTableDescriptors() {
return this.tableDescriptors;
}
/** @return InfoServer object. Maybe null.*/
public InfoServer getInfoServer() {
return this.infoServer;
}
@Override
public Configuration getConfiguration() {
return this.conf;
}
@Override
public ServerManager getServerManager() {
return this.serverManager;
}
@Override
public ExecutorService getExecutorService() {
return this.executorService;
}
@Override
public MasterFileSystem getMasterFileSystem() {
return this.fileSystemManager;
}
/**
* Get the ZK wrapper object - needed by master_jsp.java
* @return the zookeeper wrapper
*/
public ZooKeeperWatcher getZooKeeperWatcher() {
return this.zooKeeper;
}
/*
* Start up all services. If any of these threads gets an unhandled exception
* then they just die with a logged message. This should be fine because
* in general, we do not expect the master to get such unhandled exceptions
* as OOMEs; it should be lightly loaded. See what HRegionServer does if
* need to install an unexpected exception handler.
*/
private void startServiceThreads() throws IOException{
// Start the executor service pools
this.executorService.startExecutorService(ExecutorType.MASTER_OPEN_REGION,
conf.getInt("hbase.master.executor.openregion.threads", 5));
this.executorService.startExecutorService(ExecutorType.MASTER_CLOSE_REGION,
conf.getInt("hbase.master.executor.closeregion.threads", 5));
this.executorService.startExecutorService(ExecutorType.MASTER_SERVER_OPERATIONS,
conf.getInt("hbase.master.executor.serverops.threads", 3));
this.executorService.startExecutorService(ExecutorType.MASTER_META_SERVER_OPERATIONS,
conf.getInt("hbase.master.executor.serverops.threads", 5));
// We depend on there being only one instance of this executor running
// at a time. To do concurrency, would need fencing of enable/disable of
// tables.
this.executorService.startExecutorService(ExecutorType.MASTER_TABLE_OPERATIONS, 1);
// Start log cleaner thread
String n = Thread.currentThread().getName();
this.logCleaner =
new LogCleaner(conf.getInt("hbase.master.cleaner.interval", 60 * 1000),
this, conf, getMasterFileSystem().getFileSystem(),
getMasterFileSystem().getOldLogDir());
Threads.setDaemonThreadRunning(logCleaner.getThread(), n + ".oldLogCleaner");
// Put up info server.
int port = this.conf.getInt("hbase.master.info.port", 60010);
if (port >= 0) {
String a = this.conf.get("hbase.master.info.bindAddress", "0.0.0.0");
this.infoServer = new InfoServer(MASTER, a, port, false, this.conf);
this.infoServer.addServlet("status", "/master-status", MasterStatusServlet.class);
this.infoServer.addServlet("dump", "/dump", MasterDumpServlet.class);
this.infoServer.setAttribute(MASTER, this);
this.infoServer.start();
}
// Start allowing requests to happen.
this.rpcServer.openServer();
if (LOG.isDebugEnabled()) {
LOG.debug("Started service threads");
}
}
private void stopServiceThreads() {
if (LOG.isDebugEnabled()) {
LOG.debug("Stopping service threads");
}
if (this.rpcServer != null) this.rpcServer.stop();
// Clean up and close up shop
if (this.logCleaner!= null) this.logCleaner.interrupt();
if (this.infoServer != null) {
LOG.info("Stopping infoServer");
try {
this.infoServer.stop();
} catch (Exception ex) {
ex.printStackTrace();
}
}
if (this.executorService != null) this.executorService.shutdown();
}
private static Thread getAndStartBalancerChore(final HMaster master) {
String name = master.getServerName() + "-BalancerChore";
int balancerPeriod =
master.getConfiguration().getInt("hbase.balancer.period", 300000);
// Start up the load balancer chore
Chore chore = new Chore(name, balancerPeriod, master) {
@Override
protected void chore() {
master.balance();
}
};
return Threads.setDaemonThreadRunning(chore.getThread());
}
private void stopChores() {
if (this.balancerChore != null) {
this.balancerChore.interrupt();
}
if (this.catalogJanitorChore != null) {
this.catalogJanitorChore.interrupt();
}
}
@Override
public MapWritable regionServerStartup(final int port,
final long serverStartCode, final long serverCurrentTime)
throws IOException {
// Register with server manager
InetAddress ia = HBaseServer.getRemoteIp();
ServerName rs = this.serverManager.regionServerStartup(ia, port,
serverStartCode, serverCurrentTime);
// Send back some config info
MapWritable mw = createConfigurationSubset();
mw.put(new Text(HConstants.KEY_FOR_HOSTNAME_SEEN_BY_MASTER),
new Text(rs.getHostname()));
return mw;
}
/**
* @return Subset of configuration to pass initializing regionservers: e.g.
* the filesystem to use and root directory to use.
*/
protected MapWritable createConfigurationSubset() {
MapWritable mw = addConfig(new MapWritable(), HConstants.HBASE_DIR);
return addConfig(mw, "fs.default.name");
}
private MapWritable addConfig(final MapWritable mw, final String key) {
mw.put(new Text(key), new Text(this.conf.get(key)));
return mw;
}
@Override
public void regionServerReport(final byte [] sn, final HServerLoad hsl)
throws IOException {
this.serverManager.regionServerReport(ServerName.parseVersionedServerName(sn), hsl);
if (hsl != null && this.metrics != null) {
// Up our metrics.
this.metrics.incrementRequests(hsl.getTotalNumberOfRequests());
}
}
@Override
public void reportRSFatalError(byte [] sn, String errorText) {
String msg = "Region server " + Bytes.toString(sn) +
" reported a fatal error:\n" + errorText;
LOG.error(msg);
rsFatals.add(msg);
}
public boolean isMasterRunning() {
return !isStopped();
}
/**
* @return Maximum time we should run balancer for
*/
private int getBalancerCutoffTime() {
int balancerCutoffTime =
getConfiguration().getInt("hbase.balancer.max.balancing", -1);
if (balancerCutoffTime == -1) {
// No time period set so create one -- do half of balancer period.
int balancerPeriod =
getConfiguration().getInt("hbase.balancer.period", 300000);
balancerCutoffTime = balancerPeriod / 2;
// If nonsense period, set it to balancerPeriod
if (balancerCutoffTime <= 0) balancerCutoffTime = balancerPeriod;
}
return balancerCutoffTime;
}
@Override
public boolean balance() {
// If balance not true, don't run balancer.
if (!this.balanceSwitch) return false;
// Do this call outside of synchronized block.
int maximumBalanceTime = getBalancerCutoffTime();
long cutoffTime = System.currentTimeMillis() + maximumBalanceTime;
boolean balancerRan;
synchronized (this.balancer) {
// Only allow one balance run at at time.
if (this.assignmentManager.isRegionsInTransition()) {
LOG.debug("Not running balancer because " +
this.assignmentManager.getRegionsInTransition().size() +
" region(s) in transition: " +
org.apache.commons.lang.StringUtils.
abbreviate(this.assignmentManager.getRegionsInTransition().toString(), 256));
return false;
}
if (this.serverManager.areDeadServersInProgress()) {
LOG.debug("Not running balancer because processing dead regionserver(s): " +
this.serverManager.getDeadServers());
return false;
}
if (this.cpHost != null) {
try {
if (this.cpHost.preBalance()) {
LOG.debug("Coprocessor bypassing balancer request");
return false;
}
} catch (IOException ioe) {
LOG.error("Error invoking master coprocessor preBalance()", ioe);
return false;
}
}
Map<ServerName, List<HRegionInfo>> assignments =
this.assignmentManager.getAssignments();
// Returned Map from AM does not include mention of servers w/o assignments.
for (Map.Entry<ServerName, HServerLoad> e:
this.serverManager.getOnlineServers().entrySet()) {
if (!assignments.containsKey(e.getKey())) {
assignments.put(e.getKey(), new ArrayList<HRegionInfo>());
}
}
List<RegionPlan> plans = this.balancer.balanceCluster(assignments);
int rpCount = 0; // number of RegionPlans balanced so far
long totalRegPlanExecTime = 0;
balancerRan = plans != null;
if (plans != null && !plans.isEmpty()) {
for (RegionPlan plan: plans) {
LOG.info("balance " + plan);
long balStartTime = System.currentTimeMillis();
this.assignmentManager.balance(plan);
totalRegPlanExecTime += System.currentTimeMillis()-balStartTime;
rpCount++;
if (rpCount < plans.size() &&
// if performing next balance exceeds cutoff time, exit the loop
(System.currentTimeMillis() + (totalRegPlanExecTime / rpCount)) > cutoffTime) {
LOG.debug("No more balancing till next balance run; maximumBalanceTime=" +
maximumBalanceTime);
break;
}
}
}
if (this.cpHost != null) {
try {
this.cpHost.postBalance();
} catch (IOException ioe) {
// balancing already succeeded so don't change the result
LOG.error("Error invoking master coprocessor postBalance()", ioe);
}
}
}
return balancerRan;
}
@Override
public boolean balanceSwitch(final boolean b) {
boolean oldValue = this.balanceSwitch;
boolean newValue = b;
try {
if (this.cpHost != null) {
newValue = this.cpHost.preBalanceSwitch(newValue);
}
this.balanceSwitch = newValue;
LOG.info("Balance=" + newValue);
if (this.cpHost != null) {
this.cpHost.postBalanceSwitch(oldValue, newValue);
}
} catch (IOException ioe) {
LOG.warn("Error flipping balance switch", ioe);
}
return oldValue;
}
/**
* Switch for the background CatalogJanitor thread.
* Used for testing. The thread will continue to run. It will just be a noop
* if disabled.
* @param b If false, the catalog janitor won't do anything.
*/
public void setCatalogJanitorEnabled(final boolean b) {
((CatalogJanitor)this.catalogJanitorChore).setEnabled(b);
}
@Override
public void move(final byte[] encodedRegionName, final byte[] destServerName)
throws UnknownRegionException {
Pair<HRegionInfo, ServerName> p =
this.assignmentManager.getAssignment(encodedRegionName);
if (p == null)
throw new UnknownRegionException(Bytes.toStringBinary(encodedRegionName));
HRegionInfo hri = p.getFirst();
ServerName dest = null;
if (destServerName == null || destServerName.length == 0) {
LOG.info("Passed destination servername is null/empty so " +
"choosing a server at random");
this.assignmentManager.clearRegionPlan(hri);
// Unassign will reassign it elsewhere choosing random server.
this.assignmentManager.unassign(hri);
} else {
dest = new ServerName(Bytes.toString(destServerName));
try {
if (this.cpHost != null) {
if (this.cpHost.preMove(p.getFirst(), p.getSecond(), dest)) {
return;
}
}
RegionPlan rp = new RegionPlan(p.getFirst(), p.getSecond(), dest);
LOG.info("Added move plan " + rp + ", running balancer");
this.assignmentManager.balance(rp);
if (this.cpHost != null) {
this.cpHost.postMove(p.getFirst(), p.getSecond(), dest);
}
} catch (IOException ioe) {
UnknownRegionException ure = new UnknownRegionException(
Bytes.toStringBinary(encodedRegionName));
ure.initCause(ioe);
throw ure;
}
}
}
public void createTable(HTableDescriptor hTableDescriptor,
byte [][] splitKeys)
throws IOException {
if (!isMasterRunning()) {
throw new MasterNotRunningException();
}
HRegionInfo [] newRegions = getHRegionInfos(hTableDescriptor, splitKeys);
if (cpHost != null) {
cpHost.preCreateTable(hTableDescriptor, newRegions);
}
this.executorService.submit(new CreateTableHandler(this,
this.fileSystemManager, this.serverManager, hTableDescriptor, conf,
newRegions, catalogTracker, assignmentManager));
if (cpHost != null) {
cpHost.postCreateTable(hTableDescriptor, newRegions);
}
}
private HRegionInfo[] getHRegionInfos(HTableDescriptor hTableDescriptor,
byte[][] splitKeys) {
HRegionInfo[] hRegionInfos = null;
if (splitKeys == null || splitKeys.length == 0) {
hRegionInfos = new HRegionInfo[]{
new HRegionInfo(hTableDescriptor.getName(), null, null)};
} else {
int numRegions = splitKeys.length + 1;
hRegionInfos = new HRegionInfo[numRegions];
byte[] startKey = null;
byte[] endKey = null;
for (int i = 0; i < numRegions; i++) {
endKey = (i == splitKeys.length) ? null : splitKeys[i];
hRegionInfos[i] =
new HRegionInfo(hTableDescriptor.getName(), startKey, endKey);
startKey = endKey;
}
}
return hRegionInfos;
}
private static boolean isCatalogTable(final byte [] tableName) {
return Bytes.equals(tableName, HConstants.ROOT_TABLE_NAME) ||
Bytes.equals(tableName, HConstants.META_TABLE_NAME);
}
@Override
public void deleteTable(final byte [] tableName) throws IOException {
if (cpHost != null) {
cpHost.preDeleteTable(tableName);
}
this.executorService.submit(new DeleteTableHandler(tableName, this, this));
if (cpHost != null) {
cpHost.postDeleteTable(tableName);
}
}
public Pair<Integer, Integer> getAlterStatus(byte[] tableName)
throws IOException {
try {
return this.assignmentManager.getReopenStatus(tableName);
} catch (InterruptedException e) {
throw new IOException("Interrupted", e);
}
}
public void addColumn(byte [] tableName, HColumnDescriptor column)
throws IOException {
if (cpHost != null) {
if (cpHost.preAddColumn(tableName, column)) {
return;
}
}
new TableAddFamilyHandler(tableName, column, this, this).process();
if (cpHost != null) {
cpHost.postAddColumn(tableName, column);
}
}
public void modifyColumn(byte [] tableName, HColumnDescriptor descriptor)
throws IOException {
if (cpHost != null) {
if (cpHost.preModifyColumn(tableName, descriptor)) {
return;
}
}
new TableModifyFamilyHandler(tableName, descriptor, this, this).process();
if (cpHost != null) {
cpHost.postModifyColumn(tableName, descriptor);
}
}
public void deleteColumn(final byte [] tableName, final byte [] c)
throws IOException {
if (cpHost != null) {
if (cpHost.preDeleteColumn(tableName, c)) {
return;
}
}
new TableDeleteFamilyHandler(tableName, c, this, this).process();
if (cpHost != null) {
cpHost.postDeleteColumn(tableName, c);
}
}
public void enableTable(final byte [] tableName) throws IOException {
if (cpHost != null) {
cpHost.preEnableTable(tableName);
}
this.executorService.submit(new EnableTableHandler(this, tableName,
catalogTracker, assignmentManager, false));
if (cpHost != null) {
cpHost.postEnableTable(tableName);
}
}
public void disableTable(final byte [] tableName) throws IOException {
if (cpHost != null) {
cpHost.preDisableTable(tableName);
}
this.executorService.submit(new DisableTableHandler(this, tableName,
catalogTracker, assignmentManager, false));
if (cpHost != null) {
cpHost.postDisableTable(tableName);
}
}
/**
* Return the region and current deployment for the region containing
* the given row. If the region cannot be found, returns null. If it
* is found, but not currently deployed, the second element of the pair
* may be null.
*/
Pair<HRegionInfo, ServerName> getTableRegionForRow(
final byte [] tableName, final byte [] rowKey)
throws IOException {
final AtomicReference<Pair<HRegionInfo, ServerName>> result =
new AtomicReference<Pair<HRegionInfo, ServerName>>(null);
MetaScannerVisitor visitor =
new MetaScannerVisitor() {
@Override
public boolean processRow(Result data) throws IOException {
if (data == null || data.size() <= 0) {
return true;
}
Pair<HRegionInfo, ServerName> pair = MetaReader.parseCatalogResult(data);
if (pair == null) {
return false;
}
if (!Bytes.equals(pair.getFirst().getTableName(), tableName)) {
return false;
}
result.set(pair);
return true;
}
};
MetaScanner.metaScan(conf, visitor, tableName, rowKey, 1);
return result.get();
}
@Override
public void modifyTable(final byte[] tableName, HTableDescriptor htd)
throws IOException {
if (cpHost != null) {
cpHost.preModifyTable(tableName, htd);
}
this.executorService.submit(new ModifyTableHandler(tableName, htd, this,
this));
if (cpHost != null) {
cpHost.postModifyTable(tableName, htd);
}
}
@Override
public void checkTableModifiable(final byte [] tableName)
throws IOException {
String tableNameStr = Bytes.toString(tableName);
if (isCatalogTable(tableName)) {
throw new IOException("Can't modify catalog tables");
}
if (!MetaReader.tableExists(getCatalogTracker(), tableNameStr)) {
throw new TableNotFoundException(tableNameStr);
}
if (!getAssignmentManager().getZKTable().
isDisabledTable(Bytes.toString(tableName))) {
throw new TableNotDisabledException(tableName);
}
}
public void clearFromTransition(HRegionInfo hri) {
if (this.assignmentManager.isRegionInTransition(hri) != null) {
this.assignmentManager.clearRegionFromTransition(hri);
}
}
/**
* @return cluster status
*/
public ClusterStatus getClusterStatus() {
// Build Set of backup masters from ZK nodes
List<String> backupMasterStrings;
try {
backupMasterStrings = ZKUtil.listChildrenNoWatch(this.zooKeeper,
this.zooKeeper.backupMasterAddressesZNode);
} catch (KeeperException e) {
LOG.warn(this.zooKeeper.prefix("Unable to list backup servers"), e);
backupMasterStrings = new ArrayList<String>(0);
}
List<ServerName> backupMasters = new ArrayList<ServerName>(
backupMasterStrings.size());
for (String s: backupMasterStrings) {
backupMasters.add(new ServerName(s));
}
return new ClusterStatus(VersionInfo.getVersion(),
this.fileSystemManager.getClusterId(),
this.serverManager.getOnlineServers(),
this.serverManager.getDeadServers(),
this.serverName,
backupMasters,
this.assignmentManager.getRegionsInTransition(),
this.getCoprocessors());
}
public String getClusterId() {
return fileSystemManager.getClusterId();
}
/**
* The set of loaded coprocessors is stored in a static set. Since it's
* statically allocated, it does not require that HMaster's cpHost be
* initialized prior to accessing it.
* @return a String representation of the set of names of the loaded
* coprocessors.
*/
public static String getLoadedCoprocessors() {
return CoprocessorHost.getLoadedCoprocessors().toString();
}
/**
* @return timestamp in millis when HMaster was started.
*/
public long getMasterStartTime() {
return masterStartTime;
}
/**
* @return timestamp in millis when HMaster became the active master.
*/
public long getMasterActiveTime() {
return masterActiveTime;
}
/**
* @return array of coprocessor SimpleNames.
*/
public String[] getCoprocessors() {
Set<String> masterCoprocessors =
getCoprocessorHost().getCoprocessors();
return masterCoprocessors.toArray(new String[0]);
}
@Override
public void abort(final String msg, final Throwable t) {
if (cpHost != null) {
// HBASE-4014: dump a list of loaded coprocessors.
LOG.fatal("Master server abort: loaded coprocessors are: " +
getLoadedCoprocessors());
}
if (abortNow(msg, t)) {
if (t != null) LOG.fatal(msg, t);
else LOG.fatal(msg);
this.abort = true;
stop("Aborting");
}
}
/**
* We do the following in a different thread. If it is not completed
* in time, we will time it out and assume it is not easy to recover.
*
* 1. Create a new ZK session. (since our current one is expired)
* 2. Try to become a primary master again
* 3. Initialize all ZK based system trackers.
* 4. Assign root and meta. (they are already assigned, but we need to update our
* internal memory state to reflect it)
* 5. Process any RIT if any during the process of our recovery.
*
* @return True if we could successfully recover from ZK session expiry.
* @throws InterruptedException
* @throws IOException
* @throws KeeperException
* @throws ExecutionException
*/
private boolean tryRecoveringExpiredZKSession() throws InterruptedException,
IOException, KeeperException, ExecutionException {
this.zooKeeper = new ZooKeeperWatcher(conf, MASTER + ":"
+ this.serverName.getPort(), this, true);
Callable<Boolean> callable = new Callable<Boolean> () {
public Boolean call() throws InterruptedException,
IOException, KeeperException {
MonitoredTask status =
TaskMonitor.get().createStatus("Recovering expired ZK session");
try {
if (!becomeActiveMaster(status)) {
return Boolean.FALSE;
}
initializeZKBasedSystemTrackers();
// Update in-memory structures to reflect our earlier Root/Meta assignment.
assignRootAndMeta(status);
// process RIT if any
// TODO: Why does this not call AssignmentManager.joinCluster? Otherwise
// we are not processing dead servers if any.
assignmentManager.processDeadServersAndRegionsInTransition();
return Boolean.TRUE;
} finally {
status.cleanup();
}
}
};
long timeout =
conf.getLong("hbase.master.zksession.recover.timeout", 300000);
java.util.concurrent.ExecutorService executor =
Executors.newSingleThreadExecutor();
Future<Boolean> result = executor.submit(callable);
executor.shutdown();
if (executor.awaitTermination(timeout, TimeUnit.MILLISECONDS)
&& result.isDone()) {
Boolean recovered = result.get();
if (recovered != null) {
return recovered.booleanValue();
}
}
executor.shutdownNow();
return false;
}
/**
* Check to see if the current trigger for abort is due to ZooKeeper session
* expiry, and If yes, whether we can recover from ZK session expiry.
*
* @param msg Original abort message
* @param t The cause for current abort request
* @return true if we should proceed with abort operation, false other wise.
*/
private boolean abortNow(final String msg, final Throwable t) {
if (!this.isActiveMaster) {
return true;
}
if (t != null && t instanceof KeeperException.SessionExpiredException) {
try {
LOG.info("Primary Master trying to recover from ZooKeeper session " +
"expiry.");
return !tryRecoveringExpiredZKSession();
} catch (Throwable newT) {
LOG.error("Primary master encountered unexpected exception while " +
"trying to recover from ZooKeeper session" +
" expiry. Proceeding with server abort.", newT);
}
}
return true;
}
@Override
public ZooKeeperWatcher getZooKeeper() {
return zooKeeper;
}
public MasterCoprocessorHost getCoprocessorHost() {
return cpHost;
}
@Override
public ServerName getServerName() {
return this.serverName;
}
@Override
public CatalogTracker getCatalogTracker() {
return catalogTracker;
}
@Override
public AssignmentManager getAssignmentManager() {
return this.assignmentManager;
}
public MemoryBoundedLogMessageBuffer getRegionServerFatalLogBuffer() {
return rsFatals;
}
@SuppressWarnings("deprecation")
@Override
public void shutdown() {
if (cpHost != null) {
try {
cpHost.preShutdown();
} catch (IOException ioe) {
LOG.error("Error call master coprocessor preShutdown()", ioe);
}
}
if (mxBean != null) {
MBeanUtil.unregisterMBean(mxBean);
mxBean = null;
}
this.assignmentManager.shutdown();
this.serverManager.shutdownCluster();
try {
this.clusterStatusTracker.setClusterDown();
} catch (KeeperException e) {
LOG.error("ZooKeeper exception trying to set cluster as down in ZK", e);
}
}
@Override
public void stopMaster() {
if (cpHost != null) {
try {
cpHost.preStopMaster();
} catch (IOException ioe) {
LOG.error("Error call master coprocessor preStopMaster()", ioe);
}
}
stop("Stopped by " + Thread.currentThread().getName());
}
@Override
public void stop(final String why) {
LOG.info(why);
this.stopped = true;
// If we are a backup master, we need to interrupt wait
if (this.activeMasterManager != null) {
synchronized (this.activeMasterManager.clusterHasActiveMaster) {
this.activeMasterManager.clusterHasActiveMaster.notifyAll();
}
}
}
@Override
public boolean isStopped() {
return this.stopped;
}
public boolean isAborted() {
return this.abort;
}
/**
* Report whether this master is currently the active master or not.
* If not active master, we are parked on ZK waiting to become active.
*
* This method is used for testing.
*
* @return true if active master, false if not.
*/
public boolean isActiveMaster() {
return isActiveMaster;
}
/**
* Report whether this master has completed with its initialization and is
* ready. If ready, the master is also the active master. A standby master
* is never ready.
*
* This method is used for testing.
*
* @return true if master is ready to go, false if not.
*/
public boolean isInitialized() {
return initialized;
}
@Override
@Deprecated
public void assign(final byte[] regionName, final boolean force)
throws IOException {
assign(regionName);
}
@Override
public void assign(final byte [] regionName)throws IOException {
Pair<HRegionInfo, ServerName> pair =
MetaReader.getRegion(this.catalogTracker, regionName);
if (pair == null) throw new UnknownRegionException(Bytes.toString(regionName));
if (cpHost != null) {
if (cpHost.preAssign(pair.getFirst())) {
return;
}
}
assignRegion(pair.getFirst());
if (cpHost != null) {
cpHost.postAssign(pair.getFirst());
}
}
public void assignRegion(HRegionInfo hri) {
assignmentManager.assign(hri, true);
}
@Override
public void unassign(final byte [] regionName, final boolean force)
throws IOException {
Pair<HRegionInfo, ServerName> pair =
MetaReader.getRegion(this.catalogTracker, regionName);
if (pair == null) throw new UnknownRegionException(Bytes.toString(regionName));
HRegionInfo hri = pair.getFirst();
if (cpHost != null) {
if (cpHost.preUnassign(hri, force)) {
return;
}
}
if (force) {
this.assignmentManager.clearRegionFromTransition(hri);
assignRegion(hri);
} else {
this.assignmentManager.unassign(hri, force);
}
if (cpHost != null) {
cpHost.postUnassign(hri, force);
}
}
/**
* Get HTD array for given tables
* @param tableNames
* @return HTableDescriptor[]
*/
public HTableDescriptor[] getHTableDescriptors(List<String> tableNames) {
List<HTableDescriptor> list =
new ArrayList<HTableDescriptor>(tableNames.size());
for (String s: tableNames) {
HTableDescriptor htd = null;
try {
htd = this.tableDescriptors.get(s);
} catch (IOException e) {
LOG.warn("Failed getting descriptor for " + s, e);
}
if (htd == null) continue;
list.add(htd);
}
return list.toArray(new HTableDescriptor [] {});
}
/**
* Get all table descriptors
* @return All descriptors or null if none.
*/
public HTableDescriptor [] getHTableDescriptors() {
Map<String, HTableDescriptor> descriptors = null;
try {
descriptors = this.tableDescriptors.getAll();
} catch (IOException e) {
LOG.warn("Failed getting all descriptors", e);
}
return descriptors == null?
null: descriptors.values().toArray(new HTableDescriptor [] {});
}
/**
* Compute the average load across all region servers.
* Currently, this uses a very naive computation - just uses the number of
* regions being served, ignoring stats about number of requests.
* @return the average load
*/
public double getAverageLoad() {
return this.assignmentManager.getAverageLoad();
}
/**
* Utility for constructing an instance of the passed HMaster class.
* @param masterClass
* @param conf
* @return HMaster instance.
*/
public static HMaster constructMaster(Class<? extends HMaster> masterClass,
final Configuration conf) {
try {
Constructor<? extends HMaster> c =
masterClass.getConstructor(Configuration.class);
return c.newInstance(conf);
} catch (InvocationTargetException ite) {
Throwable target = ite.getTargetException() != null?
ite.getTargetException(): ite;
if (target.getCause() != null) target = target.getCause();
throw new RuntimeException("Failed construction of Master: " +
masterClass.toString(), target);
} catch (Exception e) {
throw new RuntimeException("Failed construction of Master: " +
masterClass.toString() + ((e.getCause() != null)?
e.getCause().getMessage(): ""), e);
}
}
/**
* @see org.apache.hadoop.hbase.master.HMasterCommandLine
*/
public static void main(String [] args) throws Exception {
VersionInfo.logVersion();
new HMasterCommandLine(HMaster.class).doMain(args);
}
/**
* Register bean with platform management server
*/
@SuppressWarnings("deprecation")
void registerMBean() {
MXBeanImpl mxBeanInfo = MXBeanImpl.init(this);
MBeanUtil.registerMBean("Master", "Master", mxBeanInfo);
LOG.info("Registered HMaster MXBean");
}
}