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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.master.assignment;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.DoNotRetryIOException;
import org.apache.hadoop.hbase.HBaseIOException;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.MetaTableAccessor;
import org.apache.hadoop.hbase.PleaseHoldException;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.UnknownRegionException;
import org.apache.hadoop.hbase.client.DoNotRetryRegionException;
import org.apache.hadoop.hbase.client.MasterSwitchType;
import org.apache.hadoop.hbase.client.RegionInfo;
import org.apache.hadoop.hbase.client.RegionInfoBuilder;
import org.apache.hadoop.hbase.client.RegionReplicaUtil;
import org.apache.hadoop.hbase.client.RegionStatesCount;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.TableState;
import org.apache.hadoop.hbase.exceptions.UnexpectedStateException;
import org.apache.hadoop.hbase.favored.FavoredNodesManager;
import org.apache.hadoop.hbase.favored.FavoredNodesPromoter;
import org.apache.hadoop.hbase.master.LoadBalancer;
import org.apache.hadoop.hbase.master.MasterServices;
import org.apache.hadoop.hbase.master.MetricsAssignmentManager;
import org.apache.hadoop.hbase.master.RegionPlan;
import org.apache.hadoop.hbase.master.RegionState;
import org.apache.hadoop.hbase.master.RegionState.State;
import org.apache.hadoop.hbase.master.ServerManager;
import org.apache.hadoop.hbase.master.TableStateManager;
import org.apache.hadoop.hbase.master.balancer.FavoredStochasticBalancer;
import org.apache.hadoop.hbase.master.procedure.HBCKServerCrashProcedure;
import org.apache.hadoop.hbase.master.procedure.MasterProcedureEnv;
import org.apache.hadoop.hbase.master.procedure.MasterProcedureScheduler;
import org.apache.hadoop.hbase.master.procedure.ProcedureSyncWait;
import org.apache.hadoop.hbase.master.procedure.ServerCrashProcedure;
import org.apache.hadoop.hbase.master.region.MasterRegion;
import org.apache.hadoop.hbase.procedure2.Procedure;
import org.apache.hadoop.hbase.procedure2.ProcedureEvent;
import org.apache.hadoop.hbase.procedure2.ProcedureExecutor;
import org.apache.hadoop.hbase.procedure2.ProcedureInMemoryChore;
import org.apache.hadoop.hbase.procedure2.util.StringUtils;
import org.apache.hadoop.hbase.regionserver.SequenceId;
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.Threads;
import org.apache.hadoop.hbase.util.VersionInfo;
import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.zookeeper.KeeperException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionStateTransition;
import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionStateTransition.TransitionCode;
import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.ReportRegionStateTransitionRequest;
import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.ReportRegionStateTransitionResponse;
/**
* The AssignmentManager is the coordinator for region assign/unassign operations.
*
* - In-memory states of regions and servers are stored in {@link RegionStates}.
* - hbase:meta state updates are handled by {@link RegionStateStore}.
*
* Regions are created by CreateTable, Split, Merge. Regions are deleted by DeleteTable, Split,
* Merge. Assigns are triggered by CreateTable, EnableTable, Split, Merge, ServerCrash. Unassigns
* are triggered by DisableTable, Split, Merge
*/
@InterfaceAudience.Private
public class AssignmentManager {
private static final Logger LOG = LoggerFactory.getLogger(AssignmentManager.class);
// TODO: AMv2
// - handle region migration from hbase1 to hbase2.
// - handle sys table assignment first (e.g. acl, namespace)
// - handle table priorities
// - If ServerBusyException trying to update hbase:meta, we abort the Master
// See updateRegionLocation in RegionStateStore.
//
// See also
// https://docs.google.com/document/d/1eVKa7FHdeoJ1-9o8yZcOTAQbv0u0bblBlCCzVSIn69g/edit#heading=h.ystjyrkbtoq5
// for other TODOs.
public static final String BOOTSTRAP_THREAD_POOL_SIZE_CONF_KEY =
"hbase.assignment.bootstrap.thread.pool.size";
public static final String ASSIGN_DISPATCH_WAIT_MSEC_CONF_KEY =
"hbase.assignment.dispatch.wait.msec";
private static final int DEFAULT_ASSIGN_DISPATCH_WAIT_MSEC = 150;
public static final String ASSIGN_DISPATCH_WAITQ_MAX_CONF_KEY =
"hbase.assignment.dispatch.wait.queue.max.size";
private static final int DEFAULT_ASSIGN_DISPATCH_WAITQ_MAX = 100;
public static final String RIT_CHORE_INTERVAL_MSEC_CONF_KEY =
"hbase.assignment.rit.chore.interval.msec";
private static final int DEFAULT_RIT_CHORE_INTERVAL_MSEC = 60 * 1000;
public static final String DEAD_REGION_METRIC_CHORE_INTERVAL_MSEC_CONF_KEY =
"hbase.assignment.dead.region.metric.chore.interval.msec";
private static final int DEFAULT_DEAD_REGION_METRIC_CHORE_INTERVAL_MSEC = 120 * 1000;
public static final String ASSIGN_MAX_ATTEMPTS = "hbase.assignment.maximum.attempts";
private static final int DEFAULT_ASSIGN_MAX_ATTEMPTS = Integer.MAX_VALUE;
public static final String ASSIGN_RETRY_IMMEDIATELY_MAX_ATTEMPTS =
"hbase.assignment.retry.immediately.maximum.attempts";
private static final int DEFAULT_ASSIGN_RETRY_IMMEDIATELY_MAX_ATTEMPTS = 3;
/** Region in Transition metrics threshold time */
public static final String METRICS_RIT_STUCK_WARNING_THRESHOLD =
"hbase.metrics.rit.stuck.warning.threshold";
private static final int DEFAULT_RIT_STUCK_WARNING_THRESHOLD = 60 * 1000;
public static final String UNEXPECTED_STATE_REGION = "Unexpected state for ";
private final ProcedureEvent metaAssignEvent = new ProcedureEvent<>("meta assign");
private final ProcedureEvent metaLoadEvent = new ProcedureEvent<>("meta load");
private final MetricsAssignmentManager metrics;
private final RegionInTransitionChore ritChore;
private final DeadServerMetricRegionChore deadMetricChore;
private final MasterServices master;
private final AtomicBoolean running = new AtomicBoolean(false);
private final RegionStates regionStates = new RegionStates();
private final RegionStateStore regionStateStore;
/**
* When the operator uses this configuration option, any version between the current cluster
* version and the value of "hbase.min.version.move.system.tables" does not trigger any
* auto-region movement. Auto-region movement here refers to auto-migration of system table
* regions to newer server versions. It is assumed that the configured range of versions does not
* require special handling of moving system table regions to higher versioned RegionServer. This
* auto-migration is done by {@link #checkIfShouldMoveSystemRegionAsync()}. Example: Let's assume
* the cluster is on version 1.4.0 and we have set "hbase.min.version.move.system.tables" as
* "2.0.0". Now if we upgrade one RegionServer on 1.4.0 cluster to 1.6.0 (< 2.0.0), then
* AssignmentManager will not move hbase:meta, hbase:namespace and other system table regions to
* newly brought up RegionServer 1.6.0 as part of auto-migration. However, if we upgrade one
* RegionServer on 1.4.0 cluster to 2.2.0 (> 2.0.0), then AssignmentManager will move all system
* table regions to newly brought up RegionServer 2.2.0 as part of auto-migration done by
* {@link #checkIfShouldMoveSystemRegionAsync()}. "hbase.min.version.move.system.tables" is
* introduced as part of HBASE-22923.
*/
private final String minVersionToMoveSysTables;
private static final String MIN_VERSION_MOVE_SYS_TABLES_CONFIG =
"hbase.min.version.move.system.tables";
private static final String DEFAULT_MIN_VERSION_MOVE_SYS_TABLES_CONFIG = "";
private final Map> rsReports = new HashMap<>();
private final boolean shouldAssignRegionsWithFavoredNodes;
private final int assignDispatchWaitQueueMaxSize;
private final int assignDispatchWaitMillis;
private final int assignMaxAttempts;
private final int assignRetryImmediatelyMaxAttempts;
private final MasterRegion masterRegion;
private final Object checkIfShouldMoveSystemRegionLock = new Object();
private Thread assignThread;
public AssignmentManager(MasterServices master, MasterRegion masterRegion) {
this(master, masterRegion, new RegionStateStore(master, masterRegion));
}
AssignmentManager(MasterServices master, MasterRegion masterRegion, RegionStateStore stateStore) {
this.master = master;
this.regionStateStore = stateStore;
this.metrics = new MetricsAssignmentManager();
this.masterRegion = masterRegion;
final Configuration conf = master.getConfiguration();
// Only read favored nodes if using the favored nodes load balancer.
this.shouldAssignRegionsWithFavoredNodes = FavoredStochasticBalancer.class
.isAssignableFrom(conf.getClass(HConstants.HBASE_MASTER_LOADBALANCER_CLASS, Object.class));
this.assignDispatchWaitMillis =
conf.getInt(ASSIGN_DISPATCH_WAIT_MSEC_CONF_KEY, DEFAULT_ASSIGN_DISPATCH_WAIT_MSEC);
this.assignDispatchWaitQueueMaxSize =
conf.getInt(ASSIGN_DISPATCH_WAITQ_MAX_CONF_KEY, DEFAULT_ASSIGN_DISPATCH_WAITQ_MAX);
this.assignMaxAttempts =
Math.max(1, conf.getInt(ASSIGN_MAX_ATTEMPTS, DEFAULT_ASSIGN_MAX_ATTEMPTS));
this.assignRetryImmediatelyMaxAttempts = conf.getInt(ASSIGN_RETRY_IMMEDIATELY_MAX_ATTEMPTS,
DEFAULT_ASSIGN_RETRY_IMMEDIATELY_MAX_ATTEMPTS);
int ritChoreInterval =
conf.getInt(RIT_CHORE_INTERVAL_MSEC_CONF_KEY, DEFAULT_RIT_CHORE_INTERVAL_MSEC);
this.ritChore = new RegionInTransitionChore(ritChoreInterval);
int deadRegionChoreInterval = conf.getInt(DEAD_REGION_METRIC_CHORE_INTERVAL_MSEC_CONF_KEY,
DEFAULT_DEAD_REGION_METRIC_CHORE_INTERVAL_MSEC);
if (deadRegionChoreInterval > 0) {
this.deadMetricChore = new DeadServerMetricRegionChore(deadRegionChoreInterval);
} else {
this.deadMetricChore = null;
}
minVersionToMoveSysTables =
conf.get(MIN_VERSION_MOVE_SYS_TABLES_CONFIG, DEFAULT_MIN_VERSION_MOVE_SYS_TABLES_CONFIG);
}
private void mirrorMetaLocations() throws IOException, KeeperException {
// For compatibility, mirror the meta region state to zookeeper
// And we still need to use zookeeper to publish the meta region locations to region
// server, so they can serve as ClientMetaService
ZKWatcher zk = master.getZooKeeper();
if (zk == null || !zk.getRecoverableZooKeeper().getState().isAlive()) {
// this is possible in tests, we do not provide a zk watcher or the zk watcher has been closed
return;
}
Collection metaStates = regionStates.getRegionStateNodes();
for (RegionStateNode metaState : metaStates) {
MetaTableLocator.setMetaLocation(zk, metaState.getRegionLocation(),
metaState.getRegionInfo().getReplicaId(), metaState.getState());
}
int replicaCount = metaStates.size();
// remove extra mirror locations
for (String znode : zk.getMetaReplicaNodes()) {
int replicaId = zk.getZNodePaths().getMetaReplicaIdFromZNode(znode);
if (replicaId >= replicaCount) {
MetaTableLocator.deleteMetaLocation(zk, replicaId);
}
}
}
public void start() throws IOException, KeeperException {
if (!running.compareAndSet(false, true)) {
return;
}
LOG.trace("Starting assignment manager");
// Start the Assignment Thread
startAssignmentThread();
// load meta region states.
// here we are still in the early steps of active master startup. There is only one thread(us)
// can access AssignmentManager and create region node, so here we do not need to lock the
// region node.
try (ResultScanner scanner =
masterRegion.getScanner(new Scan().addFamily(HConstants.CATALOG_FAMILY))) {
for (;;) {
Result result = scanner.next();
if (result == null) {
break;
}
RegionStateStore
.visitMetaEntry((r, regionInfo, state, regionLocation, lastHost, openSeqNum) -> {
RegionStateNode regionNode = regionStates.getOrCreateRegionStateNode(regionInfo);
regionNode.setState(state);
regionNode.setLastHost(lastHost);
regionNode.setRegionLocation(regionLocation);
regionNode.setOpenSeqNum(openSeqNum);
if (regionNode.getProcedure() != null) {
regionNode.getProcedure().stateLoaded(this, regionNode);
}
if (regionLocation != null) {
regionStates.addRegionToServer(regionNode);
}
if (RegionReplicaUtil.isDefaultReplica(regionInfo.getReplicaId())) {
setMetaAssigned(regionInfo, state == State.OPEN);
}
LOG.debug("Loaded hbase:meta {}", regionNode);
}, result);
}
}
mirrorMetaLocations();
}
/**
* Create RegionStateNode based on the TRSP list, and attach the TRSP to the RegionStateNode.
*
* This is used to restore the RIT region list, so we do not need to restore it in the loadingMeta
* method below. And it is also very important as now before submitting a TRSP, we need to attach
* it to the RegionStateNode, which acts like a guard, so we need to restore this information at
* the very beginning, before we start processing any procedures.
*/
public void setupRIT(List procs) {
procs.forEach(proc -> {
RegionInfo regionInfo = proc.getRegion();
RegionStateNode regionNode = regionStates.getOrCreateRegionStateNode(regionInfo);
TransitRegionStateProcedure existingProc = regionNode.getProcedure();
if (existingProc != null) {
// This is possible, as we will detach the procedure from the RSN before we
// actually finish the procedure. This is because that, we will detach the TRSP from the RSN
// during execution, at that time, the procedure has not been marked as done in the pv2
// framework yet, so it is possible that we schedule a new TRSP immediately and when
// arriving here, we will find out that there are multiple TRSPs for the region. But we can
// make sure that, only the last one can take the charge, the previous ones should have all
// been finished already. So here we will compare the proc id, the greater one will win.
if (existingProc.getProcId() < proc.getProcId()) {
// the new one wins, unset and set it to the new one below
regionNode.unsetProcedure(existingProc);
} else {
// the old one wins, skip
return;
}
}
LOG.info("Attach {} to {} to restore RIT", proc, regionNode);
regionNode.setProcedure(proc);
});
}
public void stop() {
if (!running.compareAndSet(true, false)) {
return;
}
LOG.info("Stopping assignment manager");
// The AM is started before the procedure executor,
// but the actual work will be loaded/submitted only once we have the executor
final boolean hasProcExecutor = master.getMasterProcedureExecutor() != null;
// Remove the RIT chore
if (hasProcExecutor) {
master.getMasterProcedureExecutor().removeChore(this.ritChore);
if (this.deadMetricChore != null) {
master.getMasterProcedureExecutor().removeChore(this.deadMetricChore);
}
}
// Stop the Assignment Thread
stopAssignmentThread();
// Stop the RegionStateStore
regionStates.clear();
// Update meta events (for testing)
if (hasProcExecutor) {
metaLoadEvent.suspend();
for (RegionInfo hri : getMetaRegionSet()) {
setMetaAssigned(hri, false);
}
}
}
public boolean isRunning() {
return running.get();
}
public Configuration getConfiguration() {
return master.getConfiguration();
}
public MetricsAssignmentManager getAssignmentManagerMetrics() {
return metrics;
}
private LoadBalancer getBalancer() {
return master.getLoadBalancer();
}
private MasterProcedureEnv getProcedureEnvironment() {
return master.getMasterProcedureExecutor().getEnvironment();
}
private MasterProcedureScheduler getProcedureScheduler() {
return getProcedureEnvironment().getProcedureScheduler();
}
int getAssignMaxAttempts() {
return assignMaxAttempts;
}
int getAssignRetryImmediatelyMaxAttempts() {
return assignRetryImmediatelyMaxAttempts;
}
public RegionStates getRegionStates() {
return regionStates;
}
/**
* Returns the regions hosted by the specified server.
*
* Notice that, for SCP, after we submit the SCP, no one can change the region list for the
* ServerStateNode so we do not need any locks here. And for other usage, this can only give you a
* snapshot of the current region list for this server, which means, right after you get the
* region list, new regions may be moved to this server or some regions may be moved out from this
* server, so you should not use it critically if you need strong consistency.
*/
public List getRegionsOnServer(ServerName serverName) {
ServerStateNode serverInfo = regionStates.getServerNode(serverName);
if (serverInfo == null) {
return Collections.emptyList();
}
return serverInfo.getRegionInfoList();
}
private RegionInfo getRegionInfo(RegionStateNode rsn) {
if (rsn.isSplit() && !rsn.getRegionInfo().isSplit()) {
// see the comments in markRegionAsSplit on why we need to do this converting.
return RegionInfoBuilder.newBuilder(rsn.getRegionInfo()).setSplit(true).setOffline(true)
.build();
} else {
return rsn.getRegionInfo();
}
}
private Stream getRegionStateNodes(TableName tableName,
boolean excludeOfflinedSplitParents) {
Stream stream = regionStates.getTableRegionStateNodes(tableName).stream();
if (excludeOfflinedSplitParents) {
return stream.filter(rsn -> !rsn.isSplit());
} else {
return stream;
}
}
public List getTableRegions(TableName tableName,
boolean excludeOfflinedSplitParents) {
return getRegionStateNodes(tableName, excludeOfflinedSplitParents).map(this::getRegionInfo)
.collect(Collectors.toList());
}
public List> getTableRegionsAndLocations(TableName tableName,
boolean excludeOfflinedSplitParents) {
return getRegionStateNodes(tableName, excludeOfflinedSplitParents)
.map(rsn -> Pair.newPair(getRegionInfo(rsn), rsn.getRegionLocation()))
.collect(Collectors.toList());
}
public RegionStateStore getRegionStateStore() {
return regionStateStore;
}
public List getFavoredNodes(final RegionInfo regionInfo) {
return this.shouldAssignRegionsWithFavoredNodes
? ((FavoredStochasticBalancer) getBalancer()).getFavoredNodes(regionInfo)
: ServerName.EMPTY_SERVER_LIST;
}
// ============================================================================================
// Table State Manager helpers
// ============================================================================================
private TableStateManager getTableStateManager() {
return master.getTableStateManager();
}
private boolean isTableEnabled(final TableName tableName) {
return getTableStateManager().isTableState(tableName, TableState.State.ENABLED);
}
private boolean isTableDisabled(final TableName tableName) {
return getTableStateManager().isTableState(tableName, TableState.State.DISABLED,
TableState.State.DISABLING);
}
// ============================================================================================
// META Helpers
// ============================================================================================
private boolean isMetaRegion(final RegionInfo regionInfo) {
return regionInfo.isMetaRegion();
}
public boolean isMetaRegion(final byte[] regionName) {
return getMetaRegionFromName(regionName) != null;
}
public RegionInfo getMetaRegionFromName(final byte[] regionName) {
for (RegionInfo hri : getMetaRegionSet()) {
if (Bytes.equals(hri.getRegionName(), regionName)) {
return hri;
}
}
return null;
}
public boolean isCarryingMeta(final ServerName serverName) {
// TODO: handle multiple meta
return isCarryingRegion(serverName, RegionInfoBuilder.FIRST_META_REGIONINFO);
}
private boolean isCarryingRegion(final ServerName serverName, final RegionInfo regionInfo) {
// TODO: check for state?
final RegionStateNode node = regionStates.getRegionStateNode(regionInfo);
return (node != null && serverName.equals(node.getRegionLocation()));
}
private RegionInfo getMetaForRegion(final RegionInfo regionInfo) {
// if (regionInfo.isMetaRegion()) return regionInfo;
// TODO: handle multiple meta. if the region provided is not meta lookup
// which meta the region belongs to.
return RegionInfoBuilder.FIRST_META_REGIONINFO;
}
// TODO: handle multiple meta.
private static final Set META_REGION_SET =
Collections.singleton(RegionInfoBuilder.FIRST_META_REGIONINFO);
public Set getMetaRegionSet() {
return META_REGION_SET;
}
// ============================================================================================
// META Event(s) helpers
// ============================================================================================
/**
* Notice that, this only means the meta region is available on a RS, but the AM may still be
* loading the region states from meta, so usually you need to check {@link #isMetaLoaded()} first
* before checking this method, unless you can make sure that your piece of code can only be
* executed after AM builds the region states.
* @see #isMetaLoaded()
*/
public boolean isMetaAssigned() {
return metaAssignEvent.isReady();
}
public boolean isMetaRegionInTransition() {
return !isMetaAssigned();
}
/**
* Notice that this event does not mean the AM has already finished region state rebuilding. See
* the comment of {@link #isMetaAssigned()} for more details.
* @see #isMetaAssigned()
*/
public boolean waitMetaAssigned(Procedure proc, RegionInfo regionInfo) {
return getMetaAssignEvent(getMetaForRegion(regionInfo)).suspendIfNotReady(proc);
}
private void setMetaAssigned(RegionInfo metaRegionInfo, boolean assigned) {
assert isMetaRegion(metaRegionInfo) : "unexpected non-meta region " + metaRegionInfo;
ProcedureEvent metaAssignEvent = getMetaAssignEvent(metaRegionInfo);
if (assigned) {
metaAssignEvent.wake(getProcedureScheduler());
} else {
metaAssignEvent.suspend();
}
}
private ProcedureEvent getMetaAssignEvent(RegionInfo metaRegionInfo) {
assert isMetaRegion(metaRegionInfo) : "unexpected non-meta region " + metaRegionInfo;
// TODO: handle multiple meta.
return metaAssignEvent;
}
/**
* Wait until AM finishes the meta loading, i.e, the region states rebuilding.
* @see #isMetaLoaded()
* @see #waitMetaAssigned(Procedure, RegionInfo)
*/
public boolean waitMetaLoaded(Procedure proc) {
return metaLoadEvent.suspendIfNotReady(proc);
}
/**
* This method will be called in master initialization method after calling
* {@link #processOfflineRegions()}, as in processOfflineRegions we will generate assign
* procedures for offline regions, which may be conflict with creating table.
*
* This is a bit dirty, should be reconsidered after we decide whether to keep the
* {@link #processOfflineRegions()} method.
*/
public void wakeMetaLoadedEvent() {
metaLoadEvent.wake(getProcedureScheduler());
assert isMetaLoaded() : "expected meta to be loaded";
}
/**
* Return whether AM finishes the meta loading, i.e, the region states rebuilding.
* @see #isMetaAssigned()
* @see #waitMetaLoaded(Procedure)
*/
public boolean isMetaLoaded() {
return metaLoadEvent.isReady();
}
/**
* Start a new thread to check if there are region servers whose versions are higher than others.
* If so, move all system table regions to RS with the highest version to keep compatibility. The
* reason is, RS in new version may not be able to access RS in old version when there are some
* incompatible changes.
*
* This method is called when a new RegionServer is added to cluster only.
*
*/
public void checkIfShouldMoveSystemRegionAsync() {
// TODO: Fix this thread. If a server is killed and a new one started, this thread thinks that
// it should 'move' the system tables from the old server to the new server but
// ServerCrashProcedure is on it; and it will take care of the assign without dataloss.
if (this.master.getServerManager().countOfRegionServers() <= 1) {
return;
}
// This thread used to run whenever there was a change in the cluster. The ZooKeeper
// childrenChanged notification came in before the nodeDeleted message and so this method
// cold run before a ServerCrashProcedure could run. That meant that this thread could see
// a Crashed Server before ServerCrashProcedure and it could find system regions on the
// crashed server and go move them before ServerCrashProcedure had a chance; could be
// dataloss too if WALs were not recovered.
new Thread(() -> {
try {
synchronized (checkIfShouldMoveSystemRegionLock) {
List plans = new ArrayList<>();
// TODO: I don't think this code does a good job if all servers in cluster have same
// version. It looks like it will schedule unnecessary moves.
for (ServerName server : getExcludedServersForSystemTable()) {
if (master.getServerManager().isServerDead(server)) {
// TODO: See HBASE-18494 and HBASE-18495. Though getExcludedServersForSystemTable()
// considers only online servers, the server could be queued for dead server
// processing. As region assignments for crashed server is handled by
// ServerCrashProcedure, do NOT handle them here. The goal is to handle this through
// regular flow of LoadBalancer as a favored node and not to have this special
// handling.
continue;
}
List regionsShouldMove = getSystemTables(server);
if (!regionsShouldMove.isEmpty()) {
for (RegionInfo regionInfo : regionsShouldMove) {
// null value for dest forces destination server to be selected by balancer
RegionPlan plan = new RegionPlan(regionInfo, server, null);
if (regionInfo.isMetaRegion()) {
// Must move meta region first.
LOG.info("Async MOVE of {} to newer Server={}", regionInfo.getEncodedName(),
server);
moveAsync(plan);
} else {
plans.add(plan);
}
}
}
for (RegionPlan plan : plans) {
LOG.info("Async MOVE of {} to newer Server={}", plan.getRegionInfo().getEncodedName(),
server);
moveAsync(plan);
}
}
}
} catch (Throwable t) {
LOG.error(t.toString(), t);
}
}).start();
}
private List getSystemTables(ServerName serverName) {
ServerStateNode serverNode = regionStates.getServerNode(serverName);
if (serverNode == null) {
return Collections.emptyList();
}
return serverNode.getSystemRegionInfoList();
}
private void preTransitCheck(RegionStateNode regionNode, RegionState.State[] expectedStates)
throws HBaseIOException {
if (regionNode.getProcedure() != null) {
throw new HBaseIOException(
regionNode + " is currently in transition; pid=" + regionNode.getProcedure().getProcId());
}
if (!regionNode.isInState(expectedStates)) {
throw new DoNotRetryRegionException(UNEXPECTED_STATE_REGION + regionNode);
}
if (isTableDisabled(regionNode.getTable())) {
throw new DoNotRetryIOException(regionNode.getTable() + " is disabled for " + regionNode);
}
}
/**
* Create an assign TransitRegionStateProcedure. Makes sure of RegionState. Throws exception if
* not appropriate UNLESS override is set. Used by hbck2 but also by straightline
* {@link #assign(RegionInfo, ServerName)} and {@link #assignAsync(RegionInfo, ServerName)}.
* @see #createAssignProcedure(RegionStateNode, ServerName) for a version that does NO checking
* used when only when no checking needed.
* @param override If false, check RegionState is appropriate for assign; if not throw exception.
*/
private TransitRegionStateProcedure createAssignProcedure(RegionInfo regionInfo, ServerName sn,
boolean override) throws IOException {
RegionStateNode regionNode = regionStates.getOrCreateRegionStateNode(regionInfo);
regionNode.lock();
try {
if (override) {
if (regionNode.getProcedure() != null) {
regionNode.unsetProcedure(regionNode.getProcedure());
}
} else {
preTransitCheck(regionNode, STATES_EXPECTED_ON_ASSIGN);
}
assert regionNode.getProcedure() == null;
return regionNode.setProcedure(
TransitRegionStateProcedure.assign(getProcedureEnvironment(), regionInfo, sn));
} finally {
regionNode.unlock();
}
}
/**
* Create an assign TransitRegionStateProcedure. Does NO checking of RegionState. Presumes
* appriopriate state ripe for assign.
* @see #createAssignProcedure(RegionInfo, ServerName, boolean)
*/
private TransitRegionStateProcedure createAssignProcedure(RegionStateNode regionNode,
ServerName targetServer) {
regionNode.lock();
try {
return regionNode.setProcedure(TransitRegionStateProcedure.assign(getProcedureEnvironment(),
regionNode.getRegionInfo(), targetServer));
} finally {
regionNode.unlock();
}
}
public long assign(RegionInfo regionInfo, ServerName sn) throws IOException {
TransitRegionStateProcedure proc = createAssignProcedure(regionInfo, sn, false);
ProcedureSyncWait.submitAndWaitProcedure(master.getMasterProcedureExecutor(), proc);
return proc.getProcId();
}
public long assign(RegionInfo regionInfo) throws IOException {
return assign(regionInfo, null);
}
/**
* Submits a procedure that assigns a region to a target server without waiting for it to finish
* @param regionInfo the region we would like to assign
* @param sn target server name
*/
public Future assignAsync(RegionInfo regionInfo, ServerName sn) throws IOException {
return ProcedureSyncWait.submitProcedure(master.getMasterProcedureExecutor(),
createAssignProcedure(regionInfo, sn, false));
}
/**
* Submits a procedure that assigns a region without waiting for it to finish
* @param regionInfo the region we would like to assign
*/
public Future assignAsync(RegionInfo regionInfo) throws IOException {
return assignAsync(regionInfo, null);
}
public long unassign(RegionInfo regionInfo) throws IOException {
RegionStateNode regionNode = regionStates.getRegionStateNode(regionInfo);
if (regionNode == null) {
throw new UnknownRegionException("No RegionState found for " + regionInfo.getEncodedName());
}
TransitRegionStateProcedure proc;
regionNode.lock();
try {
preTransitCheck(regionNode, STATES_EXPECTED_ON_UNASSIGN_OR_MOVE);
proc = TransitRegionStateProcedure.unassign(getProcedureEnvironment(), regionInfo);
regionNode.setProcedure(proc);
} finally {
regionNode.unlock();
}
ProcedureSyncWait.submitAndWaitProcedure(master.getMasterProcedureExecutor(), proc);
return proc.getProcId();
}
public TransitRegionStateProcedure createMoveRegionProcedure(RegionInfo regionInfo,
ServerName targetServer) throws HBaseIOException {
RegionStateNode regionNode = this.regionStates.getRegionStateNode(regionInfo);
if (regionNode == null) {
throw new UnknownRegionException(
"No RegionStateNode found for " + regionInfo.getEncodedName() + "(Closed/Deleted?)");
}
TransitRegionStateProcedure proc;
regionNode.lock();
try {
preTransitCheck(regionNode, STATES_EXPECTED_ON_UNASSIGN_OR_MOVE);
regionNode.checkOnline();
proc = TransitRegionStateProcedure.move(getProcedureEnvironment(), regionInfo, targetServer);
regionNode.setProcedure(proc);
} finally {
regionNode.unlock();
}
return proc;
}
public void move(RegionInfo regionInfo) throws IOException {
TransitRegionStateProcedure proc = createMoveRegionProcedure(regionInfo, null);
ProcedureSyncWait.submitAndWaitProcedure(master.getMasterProcedureExecutor(), proc);
}
public Future moveAsync(RegionPlan regionPlan) throws HBaseIOException {
TransitRegionStateProcedure proc =
createMoveRegionProcedure(regionPlan.getRegionInfo(), regionPlan.getDestination());
return ProcedureSyncWait.submitProcedure(master.getMasterProcedureExecutor(), proc);
}
public Future balance(RegionPlan regionPlan) throws HBaseIOException {
ServerName current =
this.getRegionStates().getRegionAssignments().get(regionPlan.getRegionInfo());
if (current == null || !current.equals(regionPlan.getSource())) {
LOG.debug("Skip region plan {}, source server not match, current region location is {}",
regionPlan, current == null ? "(null)" : current);
return null;
}
return moveAsync(regionPlan);
}
// ============================================================================================
// RegionTransition procedures helpers
// ============================================================================================
/**
* Create round-robin assigns. Use on table creation to distribute out regions across cluster.
* @return AssignProcedures made out of the passed in hris and a call to the balancer
* to populate the assigns with targets chosen using round-robin (default balancer
* scheme). If at assign-time, the target chosen is no longer up, thats fine, the
* AssignProcedure will ask the balancer for a new target, and so on.
*/
public TransitRegionStateProcedure[] createRoundRobinAssignProcedures(List hris,
List serversToExclude) {
if (hris.isEmpty()) {
return new TransitRegionStateProcedure[0];
}
if (
serversToExclude != null && this.master.getServerManager().getOnlineServersList().size() == 1
) {
LOG.debug("Only one region server found and hence going ahead with the assignment");
serversToExclude = null;
}
try {
// Ask the balancer to assign our regions. Pass the regions en masse. The balancer can do
// a better job if it has all the assignments in the one lump.
Map> assignments = getBalancer().roundRobinAssignment(hris,
this.master.getServerManager().createDestinationServersList(serversToExclude));
// Return mid-method!
return createAssignProcedures(assignments);
} catch (HBaseIOException hioe) {
LOG.warn("Failed roundRobinAssignment", hioe);
}
// If an error above, fall-through to this simpler assign. Last resort.
return createAssignProcedures(hris);
}
/**
* Create round-robin assigns. Use on table creation to distribute out regions across cluster.
* @return AssignProcedures made out of the passed in hris and a call to the balancer
* to populate the assigns with targets chosen using round-robin (default balancer
* scheme). If at assign-time, the target chosen is no longer up, thats fine, the
* AssignProcedure will ask the balancer for a new target, and so on.
*/
public TransitRegionStateProcedure[] createRoundRobinAssignProcedures(List hris) {
return createRoundRobinAssignProcedures(hris, null);
}
static int compare(TransitRegionStateProcedure left, TransitRegionStateProcedure right) {
if (left.getRegion().isMetaRegion()) {
if (right.getRegion().isMetaRegion()) {
return RegionInfo.COMPARATOR.compare(left.getRegion(), right.getRegion());
}
return -1;
} else if (right.getRegion().isMetaRegion()) {
return +1;
}
if (left.getRegion().getTable().isSystemTable()) {
if (right.getRegion().getTable().isSystemTable()) {
return RegionInfo.COMPARATOR.compare(left.getRegion(), right.getRegion());
}
return -1;
} else if (right.getRegion().getTable().isSystemTable()) {
return +1;
}
return RegionInfo.COMPARATOR.compare(left.getRegion(), right.getRegion());
}
/**
* Create one TransitRegionStateProcedure to assign a region w/o specifying a target server. This
* method is called from HBCK2.
* @return an assign or null
*/
public TransitRegionStateProcedure createOneAssignProcedure(RegionInfo ri, boolean override) {
TransitRegionStateProcedure trsp = null;
try {
trsp = createAssignProcedure(ri, null, override);
} catch (IOException ioe) {
LOG.info(
"Failed {} assign, override={}"
+ (override ? "" : "; set override to by-pass state checks."),
ri.getEncodedName(), override, ioe);
}
return trsp;
}
/**
* Create one TransitRegionStateProcedure to unassign a region. This method is called from HBCK2.
* @return an unassign or null
*/
public TransitRegionStateProcedure createOneUnassignProcedure(RegionInfo ri, boolean override) {
RegionStateNode regionNode = regionStates.getOrCreateRegionStateNode(ri);
TransitRegionStateProcedure trsp = null;
regionNode.lock();
try {
if (override) {
if (regionNode.getProcedure() != null) {
regionNode.unsetProcedure(regionNode.getProcedure());
}
} else {
// This is where we could throw an exception; i.e. override is false.
preTransitCheck(regionNode, STATES_EXPECTED_ON_UNASSIGN_OR_MOVE);
}
assert regionNode.getProcedure() == null;
trsp =
TransitRegionStateProcedure.unassign(getProcedureEnvironment(), regionNode.getRegionInfo());
regionNode.setProcedure(trsp);
} catch (IOException ioe) {
// 'override' must be false here.
LOG.info("Failed {} unassign, override=false; set override to by-pass state checks.",
ri.getEncodedName(), ioe);
} finally {
regionNode.unlock();
}
return trsp;
}
/**
* Create an array of TransitRegionStateProcedure w/o specifying a target server. Used as fallback
* of caller is unable to do {@link #createAssignProcedures(Map)}.
*
* If no target server, at assign time, we will try to use the former location of the region if
* one exists. This is how we 'retain' the old location across a server restart.
*
* Should only be called when you can make sure that no one can touch these regions other than
* you. For example, when you are creating or enabling table. Presumes all Regions are in
* appropriate state ripe for assign; no checking of Region state is done in here.
* @see #createAssignProcedures(Map)
*/
public TransitRegionStateProcedure[] createAssignProcedures(List hris) {
return hris.stream().map(hri -> regionStates.getOrCreateRegionStateNode(hri))
.map(regionNode -> createAssignProcedure(regionNode, null)).sorted(AssignmentManager::compare)
.toArray(TransitRegionStateProcedure[]::new);
}
/**
* Tied to {@link #createAssignProcedures(List)} in that it is called if caller is unable to run
* this method. Presumes all Regions are in appropriate state ripe for assign; no checking of
* Region state is done in here.
* @param assignments Map of assignments from which we produce an array of AssignProcedures.
* @return Assignments made from the passed in assignments
* @see #createAssignProcedures(List)
*/
private TransitRegionStateProcedure[]
createAssignProcedures(Map> assignments) {
return assignments.entrySet().stream()
.flatMap(e -> e.getValue().stream().map(hri -> regionStates.getOrCreateRegionStateNode(hri))
.map(regionNode -> createAssignProcedure(regionNode, e.getKey())))
.sorted(AssignmentManager::compare).toArray(TransitRegionStateProcedure[]::new);
}
// for creating unassign TRSP when disabling a table or closing excess region replicas
private TransitRegionStateProcedure forceCreateUnssignProcedure(RegionStateNode regionNode) {
regionNode.lock();
try {
if (regionNode.isInState(State.OFFLINE, State.CLOSED, State.SPLIT)) {
return null;
}
// in general, a split parent should be in CLOSED or SPLIT state, but anyway, let's check it
// here for safety
if (regionNode.getRegionInfo().isSplit()) {
LOG.warn("{} is a split parent but not in CLOSED or SPLIT state", regionNode);
return null;
}
// As in DisableTableProcedure or ModifyTableProcedure, we will hold the xlock for table, so
// we can make sure that this procedure has not been executed yet, as TRSP will hold the
// shared lock for table all the time. So here we will unset it and when it is actually
// executed, it will find that the attach procedure is not itself and quit immediately.
if (regionNode.getProcedure() != null) {
regionNode.unsetProcedure(regionNode.getProcedure());
}
return regionNode.setProcedure(TransitRegionStateProcedure.unassign(getProcedureEnvironment(),
regionNode.getRegionInfo()));
} finally {
regionNode.unlock();
}
}
/**
* Called by DisableTableProcedure to unassign all the regions for a table.
*/
public TransitRegionStateProcedure[] createUnassignProceduresForDisabling(TableName tableName) {
return regionStates.getTableRegionStateNodes(tableName).stream()
.map(this::forceCreateUnssignProcedure).filter(p -> p != null)
.toArray(TransitRegionStateProcedure[]::new);
}
/**
* Called by ModifyTableProcedures to unassign all the excess region replicas for a table.
*/
public TransitRegionStateProcedure[] createUnassignProceduresForClosingExcessRegionReplicas(
TableName tableName, int newReplicaCount) {
return regionStates.getTableRegionStateNodes(tableName).stream()
.filter(regionNode -> regionNode.getRegionInfo().getReplicaId() >= newReplicaCount)
.map(this::forceCreateUnssignProcedure).filter(p -> p != null)
.toArray(TransitRegionStateProcedure[]::new);
}
public SplitTableRegionProcedure createSplitProcedure(final RegionInfo regionToSplit,
final byte[] splitKey) throws IOException {
return new SplitTableRegionProcedure(getProcedureEnvironment(), regionToSplit, splitKey);
}
public MergeTableRegionsProcedure createMergeProcedure(RegionInfo... ris) throws IOException {
return new MergeTableRegionsProcedure(getProcedureEnvironment(), ris, false);
}
/**
* Delete the region states. This is called by "DeleteTable"
*/
public void deleteTable(final TableName tableName) throws IOException {
final ArrayList regions = regionStates.getTableRegionsInfo(tableName);
regionStateStore.deleteRegions(regions);
for (int i = 0; i < regions.size(); ++i) {
final RegionInfo regionInfo = regions.get(i);
regionStates.deleteRegion(regionInfo);
}
}
// ============================================================================================
// RS Region Transition Report helpers
// ============================================================================================
private void reportRegionStateTransition(ReportRegionStateTransitionResponse.Builder builder,
ServerName serverName, List transitionList) throws IOException {
for (RegionStateTransition transition : transitionList) {
switch (transition.getTransitionCode()) {
case OPENED:
case FAILED_OPEN:
case CLOSED:
assert transition.getRegionInfoCount() == 1 : transition;
final RegionInfo hri = ProtobufUtil.toRegionInfo(transition.getRegionInfo(0));
long procId =
transition.getProcIdCount() > 0 ? transition.getProcId(0) : Procedure.NO_PROC_ID;
updateRegionTransition(serverName, transition.getTransitionCode(), hri,
transition.hasOpenSeqNum() ? transition.getOpenSeqNum() : HConstants.NO_SEQNUM, procId);
break;
case READY_TO_SPLIT:
case SPLIT:
case SPLIT_REVERTED:
assert transition.getRegionInfoCount() == 3 : transition;
final RegionInfo parent = ProtobufUtil.toRegionInfo(transition.getRegionInfo(0));
final RegionInfo splitA = ProtobufUtil.toRegionInfo(transition.getRegionInfo(1));
final RegionInfo splitB = ProtobufUtil.toRegionInfo(transition.getRegionInfo(2));
updateRegionSplitTransition(serverName, transition.getTransitionCode(), parent, splitA,
splitB);
break;
case READY_TO_MERGE:
case MERGED:
case MERGE_REVERTED:
assert transition.getRegionInfoCount() == 3 : transition;
final RegionInfo merged = ProtobufUtil.toRegionInfo(transition.getRegionInfo(0));
final RegionInfo mergeA = ProtobufUtil.toRegionInfo(transition.getRegionInfo(1));
final RegionInfo mergeB = ProtobufUtil.toRegionInfo(transition.getRegionInfo(2));
updateRegionMergeTransition(serverName, transition.getTransitionCode(), merged, mergeA,
mergeB);
break;
}
}
}
public ReportRegionStateTransitionResponse reportRegionStateTransition(
final ReportRegionStateTransitionRequest req) throws PleaseHoldException {
ReportRegionStateTransitionResponse.Builder builder =
ReportRegionStateTransitionResponse.newBuilder();
ServerName serverName = ProtobufUtil.toServerName(req.getServer());
ServerStateNode serverNode = regionStates.getOrCreateServer(serverName);
// here we have to acquire a read lock instead of a simple exclusive lock. This is because that
// we should not block other reportRegionStateTransition call from the same region server. This
// is not only about performance, but also to prevent dead lock. Think of the meta region is
// also on the same region server and you hold the lock which blocks the
// reportRegionStateTransition for meta, and since meta is not online, you will block inside the
// lock protection to wait for meta online...
serverNode.readLock().lock();
try {
// we only accept reportRegionStateTransition if the region server is online, see the comment
// above in submitServerCrash method and HBASE-21508 for more details.
if (serverNode.isInState(ServerState.ONLINE)) {
try {
reportRegionStateTransition(builder, serverName, req.getTransitionList());
} catch (PleaseHoldException e) {
LOG.trace("Failed transition ", e);
throw e;
} catch (UnsupportedOperationException | IOException e) {
// TODO: at the moment we have a single error message and the RS will abort
// if the master says that one of the region transitions failed.
LOG.warn("Failed transition", e);
builder.setErrorMessage("Failed transition " + e.getMessage());
}
} else {
LOG.warn("The region server {} is already dead, skip reportRegionStateTransition call",
serverName);
builder.setErrorMessage("You are dead");
}
} finally {
serverNode.readLock().unlock();
}
return builder.build();
}
private void updateRegionTransition(ServerName serverName, TransitionCode state,
RegionInfo regionInfo, long seqId, long procId) throws IOException {
checkMetaLoaded(regionInfo);
RegionStateNode regionNode = regionStates.getRegionStateNode(regionInfo);
if (regionNode == null) {
// the table/region is gone. maybe a delete, split, merge
throw new UnexpectedStateException(String.format(
"Server %s was trying to transition region %s to %s. but Region is not known.", serverName,
regionInfo, state));
}
LOG.trace("Update region transition serverName={} region={} regionState={}", serverName,
regionNode, state);
ServerStateNode serverNode = regionStates.getOrCreateServer(serverName);
regionNode.lock();
try {
if (!reportTransition(regionNode, serverNode, state, seqId, procId)) {
// Don't log WARN if shutting down cluster; during shutdown. Avoid the below messages:
// 2018-08-13 10:45:10,551 WARN ...AssignmentManager: No matching procedure found for
// rit=OPEN, location=ve0538.halxg.cloudera.com,16020,1533493000958,
// table=IntegrationTestBigLinkedList, region=65ab289e2fc1530df65f6c3d7cde7aa5 transition
// to CLOSED
// These happen because on cluster shutdown, we currently let the RegionServers close
// regions. This is the only time that region close is not run by the Master (so cluster
// goes down fast). Consider changing it so Master runs all shutdowns.
if (
this.master.getServerManager().isClusterShutdown() && state.equals(TransitionCode.CLOSED)
) {
LOG.info("RegionServer {} {}", state, regionNode.getRegionInfo().getEncodedName());
} else {
LOG.warn("No matching procedure found for {} transition on {} to {}", serverName,
regionNode, state);
}
}
} finally {
regionNode.unlock();
}
}
private boolean reportTransition(RegionStateNode regionNode, ServerStateNode serverNode,
TransitionCode state, long seqId, long procId) throws IOException {
ServerName serverName = serverNode.getServerName();
TransitRegionStateProcedure proc = regionNode.getProcedure();
if (proc == null) {
return false;
}
proc.reportTransition(master.getMasterProcedureExecutor().getEnvironment(), regionNode,
serverName, state, seqId, procId);
return true;
}
private void updateRegionSplitTransition(final ServerName serverName, final TransitionCode state,
final RegionInfo parent, final RegionInfo hriA, final RegionInfo hriB) throws IOException {
checkMetaLoaded(parent);
if (state != TransitionCode.READY_TO_SPLIT) {
throw new UnexpectedStateException(
"unsupported split regionState=" + state + " for parent region " + parent
+ " maybe an old RS (< 2.0) had the operation in progress");
}
// sanity check on the request
if (!Bytes.equals(hriA.getEndKey(), hriB.getStartKey())) {
throw new UnsupportedOperationException("unsupported split request with bad keys: parent="
+ parent + " hriA=" + hriA + " hriB=" + hriB);
}
if (!master.isSplitOrMergeEnabled(MasterSwitchType.SPLIT)) {
LOG.warn("Split switch is off! skip split of " + parent);
throw new DoNotRetryIOException(
"Split region " + parent.getRegionNameAsString() + " failed due to split switch off");
}
// Submit the Split procedure
final byte[] splitKey = hriB.getStartKey();
if (LOG.isDebugEnabled()) {
LOG.debug("Split request from " + serverName + ", parent=" + parent + " splitKey="
+ Bytes.toStringBinary(splitKey));
}
// Processing this report happens asynchronously from other activities which can mutate
// the region state. For example, a split procedure may already be running for this parent.
// A split procedure cannot succeed if the parent region is no longer open, so we can
// ignore it in that case.
// Note that submitting more than one split procedure for a given region is
// harmless -- the split is fenced in the procedure handling -- but it would be noisy in
// the logs. Only one procedure can succeed. The other procedure(s) would abort during
// initialization and report failure with WARN level logging.
RegionState parentState = regionStates.getRegionState(parent);
if (parentState != null && parentState.isOpened()) {
master.getMasterProcedureExecutor().submitProcedure(createSplitProcedure(parent, splitKey));
} else {
LOG.info("Ignoring split request from " + serverName + ", parent=" + parent
+ " because parent is unknown or not open");
return;
}
// If the RS is < 2.0 throw an exception to abort the operation, we are handling the split
if (master.getServerManager().getVersionNumber(serverName) < 0x0200000) {
throw new UnsupportedOperationException(
String.format("Split handled by the master: " + "parent=%s hriA=%s hriB=%s",
parent.getShortNameToLog(), hriA, hriB));
}
}
private void updateRegionMergeTransition(final ServerName serverName, final TransitionCode state,
final RegionInfo merged, final RegionInfo hriA, final RegionInfo hriB) throws IOException {
checkMetaLoaded(merged);
if (state != TransitionCode.READY_TO_MERGE) {
throw new UnexpectedStateException(
"Unsupported merge regionState=" + state + " for regionA=" + hriA + " regionB=" + hriB
+ " merged=" + merged + " maybe an old RS (< 2.0) had the operation in progress");
}
if (!master.isSplitOrMergeEnabled(MasterSwitchType.MERGE)) {
LOG.warn("Merge switch is off! skip merge of regionA=" + hriA + " regionB=" + hriB);
throw new DoNotRetryIOException(
"Merge of regionA=" + hriA + " regionB=" + hriB + " failed because merge switch is off");
}
// Submit the Merge procedure
if (LOG.isDebugEnabled()) {
LOG.debug("Handling merge request from RS=" + merged + ", merged=" + merged);
}
master.getMasterProcedureExecutor().submitProcedure(createMergeProcedure(hriA, hriB));
// If the RS is < 2.0 throw an exception to abort the operation, we are handling the merge
if (master.getServerManager().getVersionNumber(serverName) < 0x0200000) {
throw new UnsupportedOperationException(
String.format("Merge not handled yet: regionState=%s merged=%s hriA=%s hriB=%s", state,
merged, hriA, hriB));
}
}
// ============================================================================================
// RS Status update (report online regions) helpers
// ============================================================================================
/**
* The master will call this method when the RS send the regionServerReport(). The report will
* contains the "online regions". This method will check the the online regions against the
* in-memory state of the AM, and we will log a warn message if there is a mismatch. This is
* because that there is no fencing between the reportRegionStateTransition method and
* regionServerReport method, so there could be race and introduce inconsistency here, but
* actually there is no problem.
*
* Please see HBASE-21421 and HBASE-21463 for more details.
*/
public void reportOnlineRegions(ServerName serverName, Set regionNames) {
if (!isRunning()) {
return;
}
if (LOG.isTraceEnabled()) {
LOG.trace("ReportOnlineRegions {} regionCount={}, metaLoaded={} {}", serverName,
regionNames.size(), isMetaLoaded(),
regionNames.stream().map(Bytes::toStringBinary).collect(Collectors.toList()));
}
ServerStateNode serverNode = regionStates.getOrCreateServer(serverName);
synchronized (serverNode) {
if (!serverNode.isInState(ServerState.ONLINE)) {
LOG.warn("Got a report from a server result in state " + serverNode.getState());
return;
}
}
// Track the regionserver reported online regions in memory.
synchronized (rsReports) {
rsReports.put(serverName, regionNames);
}
if (regionNames.isEmpty()) {
// nothing to do if we don't have regions
LOG.trace("no online region found on {}", serverName);
return;
}
if (!isMetaLoaded()) {
// we are still on startup, skip checking
return;
}
// The Heartbeat tells us of what regions are on the region serve, check the state.
checkOnlineRegionsReport(serverNode, regionNames);
}
/**
* Close regionName on sn silently and immediately without using a
* Procedure or going via hbase:meta. For case where a RegionServer's hosting of a Region is not
* aligned w/ the Master's accounting of Region state. This is for cleaning up an error in
* accounting.
*/
private void closeRegionSilently(ServerName sn, byte[] regionName) {
try {
RegionInfo ri = MetaTableAccessor.parseRegionInfoFromRegionName(regionName);
// Pass -1 for timeout. Means do not wait.
ServerManager.closeRegionSilentlyAndWait(this.master.getClusterConnection(), sn, ri, -1);
} catch (Exception e) {
LOG.error("Failed trying to close {} on {}", Bytes.toStringBinary(regionName), sn, e);
}
}
/**
* Check that what the RegionServer reports aligns with the Master's image. If disagreement, we
* will tell the RegionServer to expediently close a Region we do not think it should have.
*/
private void checkOnlineRegionsReport(ServerStateNode serverNode, Set regionNames) {
ServerName serverName = serverNode.getServerName();
for (byte[] regionName : regionNames) {
if (!isRunning()) {
return;
}
RegionStateNode regionNode = regionStates.getRegionStateNodeFromName(regionName);
if (regionNode == null) {
String regionNameAsStr = Bytes.toStringBinary(regionName);
LOG.warn("No RegionStateNode for {} but reported as up on {}; closing...", regionNameAsStr,
serverName);
closeRegionSilently(serverNode.getServerName(), regionName);
continue;
}
final long lag = 1000;
regionNode.lock();
try {
long diff = EnvironmentEdgeManager.currentTime() - regionNode.getLastUpdate();
if (regionNode.isInState(State.OPENING, State.OPEN)) {
// This is possible as a region server has just closed a region but the region server
// report is generated before the closing, but arrive after the closing. Make sure there
// is some elapsed time so less false alarms.
if (!regionNode.getRegionLocation().equals(serverName) && diff > lag) {
LOG.warn("Reporting {} server does not match {} (time since last "
+ "update={}ms); closing...", serverName, regionNode, diff);
closeRegionSilently(serverNode.getServerName(), regionName);
}
} else if (!regionNode.isInState(State.CLOSING, State.SPLITTING)) {
// So, we can get report that a region is CLOSED or SPLIT because a heartbeat
// came in at about same time as a region transition. Make sure there is some
// elapsed time so less false alarms.
if (diff > lag) {
LOG.warn("Reporting {} state does not match {} (time since last update={}ms)",
serverName, regionNode, diff);
}
}
} finally {
regionNode.unlock();
}
}
}
// ============================================================================================
// RIT chore
// ============================================================================================
private static class RegionInTransitionChore extends ProcedureInMemoryChore {
public RegionInTransitionChore(final int timeoutMsec) {
super(timeoutMsec);
}
@Override
protected void periodicExecute(final MasterProcedureEnv env) {
final AssignmentManager am = env.getAssignmentManager();
final RegionInTransitionStat ritStat = am.computeRegionInTransitionStat();
if (ritStat.hasRegionsOverThreshold()) {
for (RegionState hri : ritStat.getRegionOverThreshold()) {
am.handleRegionOverStuckWarningThreshold(hri.getRegion());
}
}
// update metrics
am.updateRegionsInTransitionMetrics(ritStat);
}
}
private static class DeadServerMetricRegionChore
extends ProcedureInMemoryChore {
public DeadServerMetricRegionChore(final int timeoutMsec) {
super(timeoutMsec);
}
@Override
protected void periodicExecute(final MasterProcedureEnv env) {
final ServerManager sm = env.getMasterServices().getServerManager();
final AssignmentManager am = env.getAssignmentManager();
// To minimize inconsistencies we are not going to snapshot live servers in advance in case
// new servers are added; OTOH we don't want to add heavy sync for a consistent view since
// this is for metrics. Instead, we're going to check each regions as we go; to avoid making
// too many checks, we maintain a local lists of server, limiting us to false negatives. If
// we miss some recently-dead server, we'll just see it next time.
Set recentlyLiveServers = new HashSet<>();
int deadRegions = 0, unknownRegions = 0;
for (RegionStateNode rsn : am.getRegionStates().getRegionStateNodes()) {
if (rsn.getState() != State.OPEN) {
continue; // Opportunistic check, should quickly skip RITs, offline tables, etc.
}
// Do not need to acquire region state lock as this is only for showing metrics.
ServerName sn = rsn.getRegionLocation();
State state = rsn.getState();
if (state != State.OPEN) {
continue; // Mostly skipping RITs that are already being take care of.
}
if (sn == null) {
++unknownRegions; // Opened on null?
continue;
}
if (recentlyLiveServers.contains(sn)) {
continue;
}
ServerManager.ServerLiveState sls = sm.isServerKnownAndOnline(sn);
switch (sls) {
case LIVE:
recentlyLiveServers.add(sn);
break;
case DEAD:
++deadRegions;
break;
case UNKNOWN:
++unknownRegions;
break;
default:
throw new AssertionError("Unexpected " + sls);
}
}
if (deadRegions > 0 || unknownRegions > 0) {
LOG.info("Found {} OPEN regions on dead servers and {} OPEN regions on unknown servers",
deadRegions, unknownRegions);
}
am.updateDeadServerRegionMetrics(deadRegions, unknownRegions);
}
}
public RegionInTransitionStat computeRegionInTransitionStat() {
final RegionInTransitionStat rit = new RegionInTransitionStat(getConfiguration());
rit.update(this);
return rit;
}
public static class RegionInTransitionStat {
private final int ritThreshold;
private HashMap ritsOverThreshold = null;
private long statTimestamp;
private long oldestRITTime = 0;
private int totalRITsTwiceThreshold = 0;
private int totalRITs = 0;
public RegionInTransitionStat(final Configuration conf) {
this.ritThreshold =
conf.getInt(METRICS_RIT_STUCK_WARNING_THRESHOLD, DEFAULT_RIT_STUCK_WARNING_THRESHOLD);
}
public int getRITThreshold() {
return ritThreshold;
}
public long getTimestamp() {
return statTimestamp;
}
public int getTotalRITs() {
return totalRITs;
}
public long getOldestRITTime() {
return oldestRITTime;
}
public int getTotalRITsOverThreshold() {
Map m = this.ritsOverThreshold;
return m != null ? m.size() : 0;
}
public boolean hasRegionsTwiceOverThreshold() {
return totalRITsTwiceThreshold > 0;
}
public boolean hasRegionsOverThreshold() {
Map m = this.ritsOverThreshold;
return m != null && !m.isEmpty();
}
public Collection getRegionOverThreshold() {
Map m = this.ritsOverThreshold;
return m != null ? m.values() : Collections.emptySet();
}
public boolean isRegionOverThreshold(final RegionInfo regionInfo) {
Map m = this.ritsOverThreshold;
return m != null && m.containsKey(regionInfo.getEncodedName());
}
public boolean isRegionTwiceOverThreshold(final RegionInfo regionInfo) {
Map m = this.ritsOverThreshold;
if (m == null) {
return false;
}
final RegionState state = m.get(regionInfo.getEncodedName());
if (state == null) {
return false;
}
return (statTimestamp - state.getStamp()) > (ritThreshold * 2);
}
protected void update(final AssignmentManager am) {
final RegionStates regionStates = am.getRegionStates();
this.statTimestamp = EnvironmentEdgeManager.currentTime();
update(regionStates.getRegionsStateInTransition(), statTimestamp);
update(regionStates.getRegionFailedOpen(), statTimestamp);
if (LOG.isDebugEnabled() && ritsOverThreshold != null && !ritsOverThreshold.isEmpty()) {
LOG.debug("RITs over threshold: {}",
ritsOverThreshold.entrySet().stream()
.map(e -> e.getKey() + ":" + e.getValue().getState().name())
.collect(Collectors.joining("\n")));
}
}
private void update(final Collection regions, final long currentTime) {
for (RegionState state : regions) {
totalRITs++;
final long ritTime = currentTime - state.getStamp();
if (ritTime > ritThreshold) {
if (ritsOverThreshold == null) {
ritsOverThreshold = new HashMap();
}
ritsOverThreshold.put(state.getRegion().getEncodedName(), state);
totalRITsTwiceThreshold += (ritTime > (ritThreshold * 2)) ? 1 : 0;
}
if (oldestRITTime < ritTime) {
oldestRITTime = ritTime;
}
}
}
}
private void updateRegionsInTransitionMetrics(final RegionInTransitionStat ritStat) {
metrics.updateRITOldestAge(ritStat.getOldestRITTime());
metrics.updateRITCount(ritStat.getTotalRITs());
metrics.updateRITCountOverThreshold(ritStat.getTotalRITsOverThreshold());
}
private void updateDeadServerRegionMetrics(int deadRegions, int unknownRegions) {
metrics.updateDeadServerOpenRegions(deadRegions);
metrics.updateUnknownServerOpenRegions(unknownRegions);
}
private void handleRegionOverStuckWarningThreshold(final RegionInfo regionInfo) {
final RegionStateNode regionNode = regionStates.getRegionStateNode(regionInfo);
// if (regionNode.isStuck()) {
LOG.warn("STUCK Region-In-Transition {}", regionNode);
}
// ============================================================================================
// TODO: Master load/bootstrap
// ============================================================================================
public void joinCluster() throws IOException {
long startTime = System.nanoTime();
LOG.debug("Joining cluster...");
// Scan hbase:meta to build list of existing regions, servers, and assignment.
// hbase:meta is online now or will be. Inside loadMeta, we keep trying. Can't make progress
// w/o meta.
loadMeta();
while (master.getServerManager().countOfRegionServers() < 1) {
LOG.info("Waiting for RegionServers to join; current count={}",
master.getServerManager().countOfRegionServers());
Threads.sleep(250);
}
LOG.info("Number of RegionServers={}", master.getServerManager().countOfRegionServers());
// Start the chores
master.getMasterProcedureExecutor().addChore(this.ritChore);
master.getMasterProcedureExecutor().addChore(this.deadMetricChore);
long costMs = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startTime);
LOG.info("Joined the cluster in {}", StringUtils.humanTimeDiff(costMs));
}
/**
* Create assign procedure for offline regions. Just follow the old
* processofflineServersWithOnlineRegions method. Since now we do not need to deal with dead
* server any more, we only deal with the regions in OFFLINE state in this method. And this is a
* bit strange, that for new regions, we will add it in CLOSED state instead of OFFLINE state, and
* usually there will be a procedure to track them. The processofflineServersWithOnlineRegions is
* a legacy from long ago, as things are going really different now, maybe we do not need this
* method any more. Need to revisit later.
*/
// Public so can be run by the Master as part of the startup. Needs hbase:meta to be online.
// Needs to be done after the table state manager has been started.
public void processOfflineRegions() {
TransitRegionStateProcedure[] procs =
regionStates.getRegionStateNodes().stream().filter(rsn -> rsn.isInState(State.OFFLINE))
.filter(rsn -> isTableEnabled(rsn.getRegionInfo().getTable())).map(rsn -> {
rsn.lock();
try {
if (rsn.getProcedure() != null) {
return null;
} else {
return rsn.setProcedure(TransitRegionStateProcedure.assign(getProcedureEnvironment(),
rsn.getRegionInfo(), null));
}
} finally {
rsn.unlock();
}
}).filter(p -> p != null).toArray(TransitRegionStateProcedure[]::new);
if (procs.length > 0) {
master.getMasterProcedureExecutor().submitProcedures(procs);
}
}
/*
* AM internal RegionStateStore.RegionStateVisitor implementation. To be used when scanning META
* table for region rows, using RegionStateStore utility methods. RegionStateStore methods will
* convert Result into proper RegionInfo instances, but those would still need to be added into
* AssignmentManager.regionStates in-memory cache. RegionMetaLoadingVisitor.visitRegionState
* method provides the logic for adding RegionInfo instances as loaded from latest META scan into
* AssignmentManager.regionStates.
*/
private class RegionMetaLoadingVisitor implements RegionStateStore.RegionStateVisitor {
@Override
public void visitRegionState(Result result, final RegionInfo regionInfo, final State state,
final ServerName regionLocation, final ServerName lastHost, final long openSeqNum) {
if (
state == null && regionLocation == null && lastHost == null
&& openSeqNum == SequenceId.NO_SEQUENCE_ID
) {
// This is a row with nothing in it.
LOG.warn("Skipping empty row={}", result);
return;
}
State localState = state;
if (localState == null) {
// No region state column data in hbase:meta table! Are I doing a rolling upgrade from
// hbase1 to hbase2? Am I restoring a SNAPSHOT or otherwise adding a region to hbase:meta?
// In any of these cases, state is empty. For now, presume OFFLINE but there are probably
// cases where we need to probe more to be sure this correct; TODO informed by experience.
LOG.info(regionInfo.getEncodedName() + " regionState=null; presuming " + State.OFFLINE);
localState = State.OFFLINE;
}
RegionStateNode regionNode = regionStates.getOrCreateRegionStateNode(regionInfo);
// Do not need to lock on regionNode, as we can make sure that before we finish loading
// meta, all the related procedures can not be executed. The only exception is for meta
// region related operations, but here we do not load the informations for meta region.
regionNode.setState(localState);
regionNode.setLastHost(lastHost);
regionNode.setRegionLocation(regionLocation);
regionNode.setOpenSeqNum(openSeqNum);
// Note: keep consistent with other methods, see region(Opening|Opened|Closing)
// RIT/ServerCrash handling should take care of the transiting regions.
if (
localState.matches(State.OPEN, State.OPENING, State.CLOSING, State.SPLITTING, State.MERGING)
) {
assert regionLocation != null : "found null region location for " + regionNode;
regionStates.addRegionToServer(regionNode);
} else if (localState == State.OFFLINE || regionInfo.isOffline()) {
regionStates.addToOfflineRegions(regionNode);
}
if (regionNode.getProcedure() != null) {
regionNode.getProcedure().stateLoaded(AssignmentManager.this, regionNode);
}
}
};
/**
* Attempt to load {@code regionInfo} from META, adding any results to the
* {@link #regionStateStore} Is NOT aware of replica regions.
* @param regionInfo the region to be loaded from META.
* @throws IOException If some error occurs while querying META or parsing results.
*/
public void populateRegionStatesFromMeta(@NonNull final RegionInfo regionInfo)
throws IOException {
final String regionEncodedName = RegionInfo.DEFAULT_REPLICA_ID == regionInfo.getReplicaId()
? regionInfo.getEncodedName()
: RegionInfoBuilder.newBuilder(regionInfo).setReplicaId(RegionInfo.DEFAULT_REPLICA_ID).build()
.getEncodedName();
populateRegionStatesFromMeta(regionEncodedName);
}
/**
* Attempt to load {@code regionEncodedName} from META, adding any results to the
* {@link #regionStateStore} Is NOT aware of replica regions.
* @param regionEncodedName encoded name for the region to be loaded from META.
* @throws IOException If some error occurs while querying META or parsing results.
*/
public void populateRegionStatesFromMeta(@NonNull String regionEncodedName) throws IOException {
final RegionMetaLoadingVisitor visitor = new RegionMetaLoadingVisitor();
regionStateStore.visitMetaForRegion(regionEncodedName, visitor);
}
private void loadMeta() throws IOException {
// TODO: use a thread pool
regionStateStore.visitMeta(new RegionMetaLoadingVisitor());
}
/**
* Used to check if the meta loading is done.
*
* if not we throw PleaseHoldException since we are rebuilding the RegionStates
* @param hri region to check if it is already rebuild
* @throws PleaseHoldException if meta has not been loaded yet
*/
private void checkMetaLoaded(RegionInfo hri) throws PleaseHoldException {
if (!isRunning()) {
throw new PleaseHoldException("AssignmentManager not running");
}
boolean meta = isMetaRegion(hri);
boolean metaLoaded = isMetaLoaded();
if (!meta && !metaLoaded) {
throw new PleaseHoldException(
"Master not fully online; hbase:meta=" + meta + ", metaLoaded=" + metaLoaded);
}
}
// ============================================================================================
// TODO: Metrics
// ============================================================================================
public int getNumRegionsOpened() {
// TODO: Used by TestRegionPlacement.java and assume monotonically increasing value
return 0;
}
/**
* Usually run by the Master in reaction to server crash during normal processing. Can also be
* invoked via external RPC to effect repair; in the latter case, the 'force' flag is set so we
* push through the SCP though context may indicate already-running-SCP (An old SCP may have
* exited abnormally, or damaged cluster may still have references in hbase:meta to 'Unknown
* Servers' -- servers that are not online or in dead servers list, etc.)
* @param force Set if the request came in externally over RPC (via hbck2). Force means run the
* SCP even if it seems as though there might be an outstanding SCP running.
* @return pid of scheduled SCP or {@link Procedure#NO_PROC_ID} if none scheduled.
*/
public long submitServerCrash(ServerName serverName, boolean shouldSplitWal, boolean force) {
// May be an 'Unknown Server' so handle case where serverNode is null.
ServerStateNode serverNode = regionStates.getServerNode(serverName);
// Remove the in-memory rsReports result
synchronized (rsReports) {
rsReports.remove(serverName);
}
// We hold the write lock here for fencing on reportRegionStateTransition. Once we set the
// server state to CRASHED, we will no longer accept the reportRegionStateTransition call from
// this server. This is used to simplify the implementation for TRSP and SCP, where we can make
// sure that, the region list fetched by SCP will not be changed any more.
if (serverNode != null) {
serverNode.writeLock().lock();
}
boolean carryingMeta;
long pid;
try {
ProcedureExecutor procExec = this.master.getMasterProcedureExecutor();
carryingMeta = isCarryingMeta(serverName);
if (!force && serverNode != null && !serverNode.isInState(ServerState.ONLINE)) {
LOG.info("Skip adding ServerCrashProcedure for {} (meta={}) -- running?", serverNode,
carryingMeta);
return Procedure.NO_PROC_ID;
} else {
MasterProcedureEnv mpe = procExec.getEnvironment();
// If serverNode == null, then 'Unknown Server'. Schedule HBCKSCP instead.
// HBCKSCP scours Master in-memory state AND hbase;meta for references to
// serverName just-in-case. An SCP that is scheduled when the server is
// 'Unknown' probably originated externally with HBCK2 fix-it tool.
ServerState oldState = null;
if (serverNode != null) {
oldState = serverNode.getState();
serverNode.setState(ServerState.CRASHED);
}
if (force) {
pid = procExec.submitProcedure(
new HBCKServerCrashProcedure(mpe, serverName, shouldSplitWal, carryingMeta));
} else {
pid = procExec.submitProcedure(
new ServerCrashProcedure(mpe, serverName, shouldSplitWal, carryingMeta));
}
LOG.info("Scheduled ServerCrashProcedure pid={} for {} (carryingMeta={}){}.", pid,
serverName, carryingMeta,
serverNode == null ? "" : " " + serverNode.toString() + ", oldState=" + oldState);
}
} finally {
if (serverNode != null) {
serverNode.writeLock().unlock();
}
}
return pid;
}
public void offlineRegion(final RegionInfo regionInfo) {
// TODO used by MasterRpcServices
RegionStateNode node = regionStates.getRegionStateNode(regionInfo);
if (node != null) {
node.offline();
}
}
public void onlineRegion(final RegionInfo regionInfo, final ServerName serverName) {
// TODO used by TestSplitTransactionOnCluster.java
}
public Map>
getSnapShotOfAssignment(final Collection regions) {
return regionStates.getSnapShotOfAssignment(regions);
}
// ============================================================================================
// TODO: UTILS/HELPERS?
// ============================================================================================
/**
* Used by the client (via master) to identify if all regions have the schema updates
* @return Pair indicating the status of the alter command (pending/total)
*/
public Pair getReopenStatus(TableName tableName) {
if (isTableDisabled(tableName)) {
return new Pair(0, 0);
}
final List states = regionStates.getTableRegionStates(tableName);
int ritCount = 0;
for (RegionState regionState : states) {
if (!regionState.isOpened() && !regionState.isSplit()) {
ritCount++;
}
}
return new Pair(ritCount, states.size());
}
// ============================================================================================
// TODO: Region State In Transition
// ============================================================================================
public boolean hasRegionsInTransition() {
return regionStates.hasRegionsInTransition();
}
public List getRegionsInTransition() {
return regionStates.getRegionsInTransition();
}
public List getAssignedRegions() {
return regionStates.getAssignedRegions();
}
/**
* Resolve a cached {@link RegionInfo} from the region name as a {@code byte[]}.
*/
public RegionInfo getRegionInfo(final byte[] regionName) {
final RegionStateNode regionState = regionStates.getRegionStateNodeFromName(regionName);
return regionState != null ? regionState.getRegionInfo() : null;
}
/**
* Resolve a cached {@link RegionInfo} from the encoded region name as a {@code String}.
*/
public RegionInfo getRegionInfo(final String encodedRegionName) {
final RegionStateNode regionState =
regionStates.getRegionStateNodeFromEncodedRegionName(encodedRegionName);
return regionState != null ? regionState.getRegionInfo() : null;
}
// ============================================================================================
// Expected states on region state transition.
// Notice that there is expected states for transiting to OPENING state, this is because SCP.
// See the comments in regionOpening method for more details.
// ============================================================================================
private static final State[] STATES_EXPECTED_ON_OPEN = { State.OPENING, // Normal case
State.OPEN // Retrying
};
private static final State[] STATES_EXPECTED_ON_CLOSING = { State.OPEN, // Normal case
State.CLOSING, // Retrying
State.SPLITTING, // Offline the split parent
State.MERGING // Offline the merge parents
};
private static final State[] STATES_EXPECTED_ON_CLOSED = { State.CLOSING, // Normal case
State.CLOSED // Retrying
};
// This is for manually scheduled region assign, can add other states later if we find out other
// usages
private static final State[] STATES_EXPECTED_ON_ASSIGN = { State.CLOSED, State.OFFLINE };
// We only allow unassign or move a region which is in OPEN state.
private static final State[] STATES_EXPECTED_ON_UNASSIGN_OR_MOVE = { State.OPEN };
// ============================================================================================
// Region Status update
// Should only be called in TransitRegionStateProcedure(and related procedures), as the locking
// and pre-assumptions are very tricky.
// ============================================================================================
private void transitStateAndUpdate(RegionStateNode regionNode, RegionState.State newState,
RegionState.State... expectedStates) throws IOException {
RegionState.State state = regionNode.getState();
regionNode.transitionState(newState, expectedStates);
boolean succ = false;
try {
regionStateStore.updateRegionLocation(regionNode);
succ = true;
} finally {
if (!succ) {
// revert
regionNode.setState(state);
}
}
}
// should be called within the synchronized block of RegionStateNode
void regionOpening(RegionStateNode regionNode) throws IOException {
// As in SCP, for performance reason, there is no TRSP attached with this region, we will not
// update the region state, which means that the region could be in any state when we want to
// assign it after a RS crash. So here we do not pass the expectedStates parameter.
transitStateAndUpdate(regionNode, State.OPENING);
regionStates.addRegionToServer(regionNode);
// update the operation count metrics
metrics.incrementOperationCounter();
}
// should be called under the RegionStateNode lock
// The parameter 'giveUp' means whether we will try to open the region again, if it is true, then
// we will persist the FAILED_OPEN state into hbase:meta.
void regionFailedOpen(RegionStateNode regionNode, boolean giveUp) throws IOException {
RegionState.State state = regionNode.getState();
ServerName regionLocation = regionNode.getRegionLocation();
if (giveUp) {
regionNode.setState(State.FAILED_OPEN);
regionNode.setRegionLocation(null);
boolean succ = false;
try {
regionStateStore.updateRegionLocation(regionNode);
succ = true;
} finally {
if (!succ) {
// revert
regionNode.setState(state);
regionNode.setRegionLocation(regionLocation);
}
}
}
if (regionLocation != null) {
regionStates.removeRegionFromServer(regionLocation, regionNode);
}
}
// should be called under the RegionStateNode lock
void regionClosing(RegionStateNode regionNode) throws IOException {
transitStateAndUpdate(regionNode, State.CLOSING, STATES_EXPECTED_ON_CLOSING);
RegionInfo hri = regionNode.getRegionInfo();
// Set meta has not initialized early. so people trying to create/edit tables will wait
if (isMetaRegion(hri)) {
setMetaAssigned(hri, false);
}
regionStates.addRegionToServer(regionNode);
// update the operation count metrics
metrics.incrementOperationCounter();
}
// for open and close, they will first be persist to the procedure store in
// RegionRemoteProcedureBase. So here we will first change the in memory state as it is considered
// as succeeded if the persistence to procedure store is succeeded, and then when the
// RegionRemoteProcedureBase is woken up, we will persist the RegionStateNode to hbase:meta.
// should be called under the RegionStateNode lock
void regionOpenedWithoutPersistingToMeta(RegionStateNode regionNode) throws IOException {
regionNode.transitionState(State.OPEN, STATES_EXPECTED_ON_OPEN);
RegionInfo regionInfo = regionNode.getRegionInfo();
regionStates.addRegionToServer(regionNode);
regionStates.removeFromFailedOpen(regionInfo);
}
// should be called under the RegionStateNode lock
void regionClosedWithoutPersistingToMeta(RegionStateNode regionNode) throws IOException {
ServerName regionLocation = regionNode.getRegionLocation();
regionNode.transitionState(State.CLOSED, STATES_EXPECTED_ON_CLOSED);
regionNode.setRegionLocation(null);
if (regionLocation != null) {
regionNode.setLastHost(regionLocation);
regionStates.removeRegionFromServer(regionLocation, regionNode);
}
}
// should be called under the RegionStateNode lock
// for SCP
public void regionClosedAbnormally(RegionStateNode regionNode) throws IOException {
RegionState.State state = regionNode.getState();
ServerName regionLocation = regionNode.getRegionLocation();
regionNode.transitionState(State.ABNORMALLY_CLOSED);
regionNode.setRegionLocation(null);
boolean succ = false;
try {
regionStateStore.updateRegionLocation(regionNode);
succ = true;
} finally {
if (!succ) {
// revert
regionNode.setState(state);
regionNode.setRegionLocation(regionLocation);
}
}
if (regionLocation != null) {
regionNode.setLastHost(regionLocation);
regionStates.removeRegionFromServer(regionLocation, regionNode);
}
}
void persistToMeta(RegionStateNode regionNode) throws IOException {
regionStateStore.updateRegionLocation(regionNode);
RegionInfo regionInfo = regionNode.getRegionInfo();
if (isMetaRegion(regionInfo) && regionNode.getState() == State.OPEN) {
// Usually we'd set a table ENABLED at this stage but hbase:meta is ALWAYs enabled, it
// can't be disabled -- so skip the RPC (besides... enabled is managed by TableStateManager
// which is backed by hbase:meta... Avoid setting ENABLED to avoid having to update state
// on table that contains state.
setMetaAssigned(regionInfo, true);
}
}
// ============================================================================================
// The above methods can only be called in TransitRegionStateProcedure(and related procedures)
// ============================================================================================
public void markRegionAsSplit(final RegionInfo parent, final ServerName serverName,
final RegionInfo daughterA, final RegionInfo daughterB) throws IOException {
// Update hbase:meta. Parent will be marked offline and split up in hbase:meta.
// The parent stays in regionStates until cleared when removed by CatalogJanitor.
// Update its state in regionStates to it shows as offline and split when read
// later figuring what regions are in a table and what are not: see
// regionStates#getRegionsOfTable
final RegionStateNode node = regionStates.getOrCreateRegionStateNode(parent);
node.setState(State.SPLIT);
final RegionStateNode nodeA = regionStates.getOrCreateRegionStateNode(daughterA);
nodeA.setState(State.SPLITTING_NEW);
final RegionStateNode nodeB = regionStates.getOrCreateRegionStateNode(daughterB);
nodeB.setState(State.SPLITTING_NEW);
// TODO: here we just update the parent region info in meta, to set split and offline to true,
// without changing the one in the region node. This is a bit confusing but the region info
// field in RegionStateNode is not expected to be changed in the current design. Need to find a
// possible way to address this problem, or at least adding more comments about the trick to
// deal with this problem, that when you want to filter out split parent, you need to check both
// the RegionState on whether it is split, and also the region info. If one of them matches then
// it is a split parent. And usually only one of them can match, as after restart, the region
// state will be changed from SPLIT to CLOSED.
regionStateStore.splitRegion(parent, daughterA, daughterB, serverName);
if (shouldAssignFavoredNodes(parent)) {
List onlineServers = this.master.getServerManager().getOnlineServersList();
((FavoredNodesPromoter) getBalancer()).generateFavoredNodesForDaughter(onlineServers, parent,
daughterA, daughterB);
}
}
/**
* When called here, the merge has happened. The merged regions have been unassigned and the above
* markRegionClosed has been called on each so they have been disassociated from a hosting Server.
* The merged region will be open after this call. The merged regions are removed from hbase:meta
* below. Later they are deleted from the filesystem by the catalog janitor running against
* hbase:meta. It notices when the merged region no longer holds references to the old regions
* (References are deleted after a compaction rewrites what the Reference points at but not until
* the archiver chore runs, are the References removed).
*/
public void markRegionAsMerged(final RegionInfo child, final ServerName serverName,
RegionInfo[] mergeParents) throws IOException {
final RegionStateNode node = regionStates.getOrCreateRegionStateNode(child);
node.setState(State.MERGED);
for (RegionInfo ri : mergeParents) {
regionStates.deleteRegion(ri);
}
regionStateStore.mergeRegions(child, mergeParents, serverName);
if (shouldAssignFavoredNodes(child)) {
((FavoredNodesPromoter) getBalancer()).generateFavoredNodesForMergedRegion(child,
mergeParents);
}
}
/*
* Favored nodes should be applied only when FavoredNodes balancer is configured and the region
* belongs to a non-system table.
*/
private boolean shouldAssignFavoredNodes(RegionInfo region) {
return this.shouldAssignRegionsWithFavoredNodes
&& FavoredNodesManager.isFavoredNodeApplicable(region);
}
// ============================================================================================
// Assign Queue (Assign/Balance)
// ============================================================================================
private final ArrayList pendingAssignQueue = new ArrayList();
private final ReentrantLock assignQueueLock = new ReentrantLock();
private final Condition assignQueueFullCond = assignQueueLock.newCondition();
/**
* Add the assign operation to the assignment queue. The pending assignment operation will be
* processed, and each region will be assigned by a server using the balancer.
*/
protected void queueAssign(final RegionStateNode regionNode) {
regionNode.getProcedureEvent().suspend();
// TODO: quick-start for meta and the other sys-tables?
assignQueueLock.lock();
try {
pendingAssignQueue.add(regionNode);
if (
regionNode.isSystemTable() || pendingAssignQueue.size() == 1
|| pendingAssignQueue.size() >= assignDispatchWaitQueueMaxSize
) {
assignQueueFullCond.signal();
}
} finally {
assignQueueLock.unlock();
}
}
private void startAssignmentThread() {
assignThread = new Thread(master.getServerName().toShortString()) {
@Override
public void run() {
while (isRunning()) {
processAssignQueue();
}
pendingAssignQueue.clear();
}
};
assignThread.setDaemon(true);
assignThread.start();
}
private void stopAssignmentThread() {
assignQueueSignal();
try {
while (assignThread.isAlive()) {
assignQueueSignal();
assignThread.join(250);
}
} catch (InterruptedException e) {
LOG.warn("join interrupted", e);
Thread.currentThread().interrupt();
}
}
private void assignQueueSignal() {
assignQueueLock.lock();
try {
assignQueueFullCond.signal();
} finally {
assignQueueLock.unlock();
}
}
@edu.umd.cs.findbugs.annotations.SuppressWarnings("WA_AWAIT_NOT_IN_LOOP")
private HashMap waitOnAssignQueue() {
HashMap regions = null;
assignQueueLock.lock();
try {
if (pendingAssignQueue.isEmpty() && isRunning()) {
assignQueueFullCond.await();
}
if (!isRunning()) {
return null;
}
assignQueueFullCond.await(assignDispatchWaitMillis, TimeUnit.MILLISECONDS);
regions = new HashMap(pendingAssignQueue.size());
for (RegionStateNode regionNode : pendingAssignQueue) {
regions.put(regionNode.getRegionInfo(), regionNode);
}
pendingAssignQueue.clear();
} catch (InterruptedException e) {
LOG.warn("got interrupted ", e);
Thread.currentThread().interrupt();
} finally {
assignQueueLock.unlock();
}
return regions;
}
private void processAssignQueue() {
final HashMap regions = waitOnAssignQueue();
if (regions == null || regions.size() == 0 || !isRunning()) {
return;
}
if (LOG.isTraceEnabled()) {
LOG.trace("PROCESS ASSIGN QUEUE regionCount=" + regions.size());
}
// TODO: Optimize balancer. pass a RegionPlan?
final HashMap retainMap = new HashMap<>();
final List userHRIs = new ArrayList<>(regions.size());
// Regions for system tables requiring reassignment
final List systemHRIs = new ArrayList<>();
for (RegionStateNode regionStateNode : regions.values()) {
boolean sysTable = regionStateNode.isSystemTable();
final List hris = sysTable ? systemHRIs : userHRIs;
if (regionStateNode.getRegionLocation() != null) {
retainMap.put(regionStateNode.getRegionInfo(), regionStateNode.getRegionLocation());
} else {
hris.add(regionStateNode.getRegionInfo());
}
}
// TODO: connect with the listener to invalidate the cache
// TODO use events
List servers = master.getServerManager().createDestinationServersList();
for (int i = 0; servers.size() < 1; ++i) {
// Report every fourth time around this loop; try not to flood log.
if (i % 4 == 0) {
LOG.warn("No servers available; cannot place " + regions.size() + " unassigned regions.");
}
if (!isRunning()) {
LOG.debug("Stopped! Dropping assign of " + regions.size() + " queued regions.");
return;
}
Threads.sleep(250);
servers = master.getServerManager().createDestinationServersList();
}
if (!systemHRIs.isEmpty()) {
// System table regions requiring reassignment are present, get region servers
// not available for system table regions
final List excludeServers = getExcludedServersForSystemTable();
List serversForSysTables =
servers.stream().filter(s -> !excludeServers.contains(s)).collect(Collectors.toList());
if (serversForSysTables.isEmpty()) {
LOG.warn("Filtering old server versions and the excluded produced an empty set; "
+ "instead considering all candidate servers!");
}
LOG.debug("Processing assignQueue; systemServersCount=" + serversForSysTables.size()
+ ", allServersCount=" + servers.size());
processAssignmentPlans(regions, null, systemHRIs,
serversForSysTables.isEmpty() && !containsBogusAssignments(regions, systemHRIs)
? servers
: serversForSysTables);
}
processAssignmentPlans(regions, retainMap, userHRIs, servers);
}
private boolean containsBogusAssignments(Map regions,
List hirs) {
for (RegionInfo ri : hirs) {
if (
regions.get(ri).getRegionLocation() != null
&& regions.get(ri).getRegionLocation().equals(LoadBalancer.BOGUS_SERVER_NAME)
) {
return true;
}
}
return false;
}
private void processAssignmentPlans(final HashMap regions,
final HashMap retainMap, final List hris,
final List servers) {
boolean isTraceEnabled = LOG.isTraceEnabled();
if (isTraceEnabled) {
LOG.trace("Available servers count=" + servers.size() + ": " + servers);
}
final LoadBalancer balancer = getBalancer();
// ask the balancer where to place regions
if (retainMap != null && !retainMap.isEmpty()) {
if (isTraceEnabled) {
LOG.trace("retain assign regions=" + retainMap);
}
try {
acceptPlan(regions, balancer.retainAssignment(retainMap, servers));
} catch (HBaseIOException e) {
LOG.warn("unable to retain assignment", e);
addToPendingAssignment(regions, retainMap.keySet());
}
}
// TODO: Do we need to split retain and round-robin?
// the retain seems to fallback to round-robin/random if the region is not in the map.
if (!hris.isEmpty()) {
Collections.sort(hris, RegionInfo.COMPARATOR);
if (isTraceEnabled) {
LOG.trace("round robin regions=" + hris);
}
try {
acceptPlan(regions, balancer.roundRobinAssignment(hris, servers));
} catch (HBaseIOException e) {
LOG.warn("unable to round-robin assignment", e);
addToPendingAssignment(regions, hris);
}
}
}
private void acceptPlan(final HashMap regions,
final Map> plan) throws HBaseIOException {
final ProcedureEvent[] events = new ProcedureEvent[regions.size()];
final long st = EnvironmentEdgeManager.currentTime();
if (plan.isEmpty()) {
throw new HBaseIOException("unable to compute plans for regions=" + regions.size());
}
int evcount = 0;
for (Map.Entry> entry : plan.entrySet()) {
final ServerName server = entry.getKey();
for (RegionInfo hri : entry.getValue()) {
final RegionStateNode regionNode = regions.get(hri);
regionNode.setRegionLocation(server);
if (server.equals(LoadBalancer.BOGUS_SERVER_NAME) && regionNode.isSystemTable()) {
assignQueueLock.lock();
try {
pendingAssignQueue.add(regionNode);
} finally {
assignQueueLock.unlock();
}
} else {
events[evcount++] = regionNode.getProcedureEvent();
}
}
}
ProcedureEvent.wakeEvents(getProcedureScheduler(), events);
final long et = EnvironmentEdgeManager.currentTime();
if (LOG.isTraceEnabled()) {
LOG.trace("ASSIGN ACCEPT " + events.length + " -> " + StringUtils.humanTimeDiff(et - st));
}
}
private void addToPendingAssignment(final HashMap regions,
final Collection pendingRegions) {
assignQueueLock.lock();
try {
for (RegionInfo hri : pendingRegions) {
pendingAssignQueue.add(regions.get(hri));
}
} finally {
assignQueueLock.unlock();
}
}
/**
* For a given cluster with mixed versions of servers, get a list of servers with lower versions,
* where system table regions should not be assigned to. For system table, we must assign regions
* to a server with highest version. However, we can disable this exclusion using config:
* "hbase.min.version.move.system.tables" if checkForMinVersion is true. Detailed explanation
* available with definition of minVersionToMoveSysTables.
* @return List of Excluded servers for System table regions.
*/
public List getExcludedServersForSystemTable() {
// TODO: This should be a cached list kept by the ServerManager rather than calculated on each
// move or system region assign. The RegionServerTracker keeps list of online Servers with
// RegionServerInfo that includes Version.
List> serverList =
master.getServerManager().getOnlineServersList().stream()
.map(s -> new Pair<>(s, master.getRegionServerVersion(s))).collect(Collectors.toList());
if (serverList.isEmpty()) {
return new ArrayList<>();
}
String highestVersion = Collections
.max(serverList, (o1, o2) -> VersionInfo.compareVersion(o1.getSecond(), o2.getSecond()))
.getSecond();
if (!DEFAULT_MIN_VERSION_MOVE_SYS_TABLES_CONFIG.equals(minVersionToMoveSysTables)) {
int comparedValue = VersionInfo.compareVersion(minVersionToMoveSysTables, highestVersion);
if (comparedValue > 0) {
return new ArrayList<>();
}
}
return serverList.stream().filter(pair -> !pair.getSecond().equals(highestVersion))
.map(Pair::getFirst).collect(Collectors.toList());
}
MasterServices getMaster() {
return master;
}
/** Returns a snapshot of rsReports */
public Map> getRSReports() {
Map> rsReportsSnapshot = new HashMap<>();
synchronized (rsReports) {
rsReports.entrySet().forEach(e -> rsReportsSnapshot.put(e.getKey(), e.getValue()));
}
return rsReportsSnapshot;
}
/**
* Provide regions state count for given table. e.g howmany regions of give table are
* opened/closed/rit etc
* @param tableName TableName
* @return region states count
*/
public RegionStatesCount getRegionStatesCount(TableName tableName) {
int openRegionsCount = 0;
int closedRegionCount = 0;
int ritCount = 0;
int splitRegionCount = 0;
int totalRegionCount = 0;
if (!isTableDisabled(tableName)) {
final List states = regionStates.getTableRegionStates(tableName);
for (RegionState regionState : states) {
if (regionState.isOpened()) {
openRegionsCount++;
} else if (regionState.isClosed()) {
closedRegionCount++;
} else if (regionState.isSplit()) {
splitRegionCount++;
}
}
totalRegionCount = states.size();
ritCount = totalRegionCount - openRegionsCount - splitRegionCount;
}
return new RegionStatesCount.RegionStatesCountBuilder().setOpenRegions(openRegionsCount)
.setClosedRegions(closedRegionCount).setSplitRegions(splitRegionCount)
.setRegionsInTransition(ritCount).setTotalRegions(totalRegionCount).build();
}
}