org.apache.hadoop.hbase.regionserver.snapshot.RegionServerSnapshotManager Maven / Gradle / Ivy
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.regionserver.snapshot;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Abortable;
import org.apache.hadoop.hbase.DroppedSnapshotException;
import org.apache.hadoop.hbase.HBaseInterfaceAudience;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.RegionReplicaUtil;
import org.apache.hadoop.hbase.errorhandling.ForeignException;
import org.apache.hadoop.hbase.errorhandling.ForeignExceptionDispatcher;
import org.apache.hadoop.hbase.master.snapshot.MasterSnapshotVerifier;
import org.apache.hadoop.hbase.master.snapshot.SnapshotManager;
import org.apache.hadoop.hbase.procedure.ProcedureMember;
import org.apache.hadoop.hbase.procedure.ProcedureMemberRpcs;
import org.apache.hadoop.hbase.procedure.RegionServerProcedureManager;
import org.apache.hadoop.hbase.procedure.Subprocedure;
import org.apache.hadoop.hbase.procedure.SubprocedureFactory;
import org.apache.hadoop.hbase.procedure.ZKProcedureMemberRpcs;
import org.apache.hadoop.hbase.regionserver.HRegion;
import org.apache.hadoop.hbase.regionserver.HRegionServer;
import org.apache.hadoop.hbase.regionserver.RegionServerServices;
import org.apache.hadoop.hbase.util.Threads;
import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.yetus.audience.InterfaceStability;
import org.apache.zookeeper.KeeperException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hbase.thirdparty.com.google.common.util.concurrent.ThreadFactoryBuilder;
import org.apache.hadoop.hbase.shaded.protobuf.generated.SnapshotProtos.SnapshotDescription;
/**
* This manager class handles the work dealing with snapshots for a {@link HRegionServer}.
*
* This provides the mechanism necessary to kick off a online snapshot specific {@link Subprocedure}
* that is responsible for the regions being served by this region server. If any failures occur
* with the subprocedure, the RegionSeverSnapshotManager's subprocedure handler,
* {@link ProcedureMember}, notifies the master's ProcedureCoordinator to abort all others.
*
* On startup, requires {@link #start()} to be called.
*
* On shutdown, requires {@link #stop(boolean)} to be called
*/
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG)
@InterfaceStability.Unstable
public class RegionServerSnapshotManager extends RegionServerProcedureManager {
private static final Logger LOG = LoggerFactory.getLogger(RegionServerSnapshotManager.class);
/** Maximum number of snapshot region tasks that can run concurrently */
private static final String CONCURENT_SNAPSHOT_TASKS_KEY =
"hbase.snapshot.region.concurrentTasks";
private static final int DEFAULT_CONCURRENT_SNAPSHOT_TASKS = 3;
/** Conf key for number of request threads to start snapshots on regionservers */
public static final String SNAPSHOT_REQUEST_THREADS_KEY = "hbase.snapshot.region.pool.threads";
/** # of threads for snapshotting regions on the rs. */
public static final int SNAPSHOT_REQUEST_THREADS_DEFAULT = 10;
/** Conf key for max time to keep threads in snapshot request pool waiting */
public static final String SNAPSHOT_TIMEOUT_MILLIS_KEY = "hbase.snapshot.region.timeout";
/** Keep threads alive in request pool for max of 300 seconds */
public static final long SNAPSHOT_TIMEOUT_MILLIS_DEFAULT = 5 * 60000;
/** Conf key for millis between checks to see if snapshot completed or if there are errors */
public static final String SNAPSHOT_REQUEST_WAKE_MILLIS_KEY =
"hbase.snapshot.region.wakefrequency";
/** Default amount of time to check for errors while regions finish snapshotting */
private static final long SNAPSHOT_REQUEST_WAKE_MILLIS_DEFAULT = 500;
private RegionServerServices rss;
private ProcedureMemberRpcs memberRpcs;
private ProcedureMember member;
/**
* Exposed for testing.
* @param conf HBase configuration.
* @param parent parent running the snapshot handler
* @param memberRpc use specified memberRpc instance
* @param procMember use specified ProcedureMember
*/
RegionServerSnapshotManager(Configuration conf, HRegionServer parent,
ProcedureMemberRpcs memberRpc, ProcedureMember procMember) {
this.rss = parent;
this.memberRpcs = memberRpc;
this.member = procMember;
}
public RegionServerSnapshotManager() {
}
/**
* Start accepting snapshot requests.
*/
@Override
public void start() {
LOG.debug("Start Snapshot Manager " + rss.getServerName().toString());
this.memberRpcs.start(rss.getServerName().toString(), member);
}
/**
* Close this and all running snapshot tasks
* @param force forcefully stop all running tasks
*/
@Override
public void stop(boolean force) throws IOException {
String mode = force ? "abruptly" : "gracefully";
LOG.info("Stopping RegionServerSnapshotManager " + mode + ".");
try {
this.member.close();
} finally {
this.memberRpcs.close();
}
}
/**
* If in a running state, creates the specified subprocedure for handling an online snapshot.
* Because this gets the local list of regions to snapshot and not the set the master had, there
* is a possibility of a race where regions may be missed. This detected by the master in the
* snapshot verification step.
* @return Subprocedure to submit to the ProcedureMember.
*/
public Subprocedure buildSubprocedure(SnapshotDescription snapshot) {
// don't run a snapshot if the parent is stop(ping)
if (rss.isStopping() || rss.isStopped()) {
throw new IllegalStateException(
"Can't start snapshot on RS: " + rss.getServerName() + ", because stopping/stopped!");
}
// check to see if this server is hosting any regions for the snapshots
// check to see if we have regions for the snapshot
List involvedRegions;
try {
involvedRegions = getRegionsToSnapshot(snapshot);
} catch (IOException e1) {
throw new IllegalStateException("Failed to figure out if we should handle a snapshot - "
+ "something has gone awry with the online regions.", e1);
}
// We need to run the subprocedure even if we have no relevant regions. The coordinator
// expects participation in the procedure and without sending message the snapshot attempt
// will hang and fail.
LOG.debug("Launching subprocedure for snapshot " + snapshot.getName() + " from table "
+ snapshot.getTable() + " type " + snapshot.getType());
ForeignExceptionDispatcher exnDispatcher = new ForeignExceptionDispatcher(snapshot.getName());
Configuration conf = rss.getConfiguration();
long timeoutMillis = conf.getLong(SNAPSHOT_TIMEOUT_MILLIS_KEY, SNAPSHOT_TIMEOUT_MILLIS_DEFAULT);
long wakeMillis =
conf.getLong(SNAPSHOT_REQUEST_WAKE_MILLIS_KEY, SNAPSHOT_REQUEST_WAKE_MILLIS_DEFAULT);
switch (snapshot.getType()) {
case FLUSH:
SnapshotSubprocedurePool taskManager =
new SnapshotSubprocedurePool(rss.getServerName().toString(), conf, rss);
return new FlushSnapshotSubprocedure(member, exnDispatcher, wakeMillis, timeoutMillis,
involvedRegions, snapshot, taskManager);
case SKIPFLUSH:
/*
* This is to take an online-snapshot without force a coordinated flush to prevent pause The
* snapshot type is defined inside the snapshot description. FlushSnapshotSubprocedure
* should be renamed to distributedSnapshotSubprocedure, and the flush() behavior can be
* turned on/off based on the flush type. To minimized the code change, class name is not
* changed.
*/
SnapshotSubprocedurePool taskManager2 =
new SnapshotSubprocedurePool(rss.getServerName().toString(), conf, rss);
return new FlushSnapshotSubprocedure(member, exnDispatcher, wakeMillis, timeoutMillis,
involvedRegions, snapshot, taskManager2);
default:
throw new UnsupportedOperationException("Unrecognized snapshot type:" + snapshot.getType());
}
}
/**
* Determine if the snapshot should be handled on this server NOTE: This is racy -- the master
* expects a list of regionservers. This means if a region moves somewhere between the calls we'll
* miss some regions. For example, a region move during a snapshot could result in a region to be
* skipped or done twice. This is manageable because the {@link MasterSnapshotVerifier} will
* double check the region lists after the online portion of the snapshot completes and will
* explicitly fail the snapshot.
* @return the list of online regions. Empty list is returned if no regions are responsible for
* the given snapshot.
*/
private List getRegionsToSnapshot(SnapshotDescription snapshot) throws IOException {
List onlineRegions =
(List) rss.getRegions(TableName.valueOf(snapshot.getTable()));
Iterator iterator = onlineRegions.iterator();
// remove the non-default regions
while (iterator.hasNext()) {
HRegion r = iterator.next();
if (!RegionReplicaUtil.isDefaultReplica(r.getRegionInfo())) {
iterator.remove();
}
}
return onlineRegions;
}
/**
* Build the actual snapshot runner that will do all the 'hard' work
*/
public class SnapshotSubprocedureBuilder implements SubprocedureFactory {
@Override
public Subprocedure buildSubprocedure(String name, byte[] data) {
try {
// unwrap the snapshot information
SnapshotDescription snapshot = SnapshotDescription.parseFrom(data);
return RegionServerSnapshotManager.this.buildSubprocedure(snapshot);
} catch (IOException e) {
throw new IllegalArgumentException("Could not read snapshot information from request.");
}
}
}
/**
* We use the SnapshotSubprocedurePool, a class specific thread pool instead of
* {@link org.apache.hadoop.hbase.executor.ExecutorService}. It uses a
* {@link java.util.concurrent.ExecutorCompletionService} which provides queuing of completed
* tasks which lets us efficiently cancel pending tasks upon the earliest operation failures.
* HBase's ExecutorService (different from {@link java.util.concurrent.ExecutorService}) isn't
* really built for coordinated tasks where multiple threads as part of one larger task. In RS's
* the HBase Executor services are only used for open and close and not other threadpooled
* operations such as compactions and replication sinks.
*/
static class SnapshotSubprocedurePool {
private final Abortable abortable;
private final ExecutorCompletionService taskPool;
private final ThreadPoolExecutor executor;
private volatile boolean stopped;
private final List> futures = new ArrayList<>();
private final String name;
SnapshotSubprocedurePool(String name, Configuration conf, Abortable abortable) {
this.abortable = abortable;
// configure the executor service
long keepAlive = conf.getLong(RegionServerSnapshotManager.SNAPSHOT_TIMEOUT_MILLIS_KEY,
RegionServerSnapshotManager.SNAPSHOT_TIMEOUT_MILLIS_DEFAULT);
int threads = conf.getInt(CONCURENT_SNAPSHOT_TASKS_KEY, DEFAULT_CONCURRENT_SNAPSHOT_TASKS);
this.name = name;
executor = Threads.getBoundedCachedThreadPool(threads, keepAlive, TimeUnit.MILLISECONDS,
new ThreadFactoryBuilder().setNameFormat("rs(" + name + ")-snapshot-pool-%d")
.setDaemon(true).setUncaughtExceptionHandler(Threads.LOGGING_EXCEPTION_HANDLER).build());
taskPool = new ExecutorCompletionService<>(executor);
}
boolean hasTasks() {
return futures.size() != 0;
}
/**
* Submit a task to the pool. NOTE: all must be submitted before you can safely
* {@link #waitForOutstandingTasks()}. This version does not support issuing tasks from multiple
* concurrent table snapshots requests.
*/
void submitTask(final Callable task) {
Future f = this.taskPool.submit(task);
futures.add(f);
}
/**
* Wait for all of the currently outstanding tasks submitted via {@link #submitTask(Callable)}.
* This *must* be called after all tasks are submitted via submitTask.
* @return true on success, false otherwise
* @throws SnapshotCreationException if the snapshot failed while we were waiting
*/
boolean waitForOutstandingTasks() throws ForeignException, InterruptedException {
LOG.debug("Waiting for local region snapshots to finish.");
int sz = futures.size();
try {
// Using the completion service to process the futures that finish first first.
for (int i = 0; i < sz; i++) {
Future f = taskPool.take();
f.get();
if (!futures.remove(f)) {
LOG.warn("unexpected future" + f);
}
LOG.debug("Completed " + (i + 1) + "/" + sz + " local region snapshots.");
}
LOG.debug("Completed " + sz + " local region snapshots.");
return true;
} catch (InterruptedException e) {
LOG.warn("Got InterruptedException in SnapshotSubprocedurePool", e);
if (!stopped) {
Thread.currentThread().interrupt();
throw new ForeignException("SnapshotSubprocedurePool", e);
}
// we are stopped so we can just exit.
} catch (ExecutionException e) {
Throwable cause = e.getCause();
if (cause instanceof ForeignException) {
LOG.warn("Rethrowing ForeignException from SnapshotSubprocedurePool", e);
throw (ForeignException) e.getCause();
} else if (cause instanceof DroppedSnapshotException) {
// we have to abort the region server according to contract of flush
abortable.abort("Received DroppedSnapshotException, aborting", cause);
}
LOG.warn("Got Exception in SnapshotSubprocedurePool", e);
throw new ForeignException(name, e.getCause());
} finally {
cancelTasks();
}
return false;
}
/**
* This attempts to cancel out all pending and in progress tasks (interruptions issues)
*/
void cancelTasks() throws InterruptedException {
Collection> tasks = futures;
LOG.debug("cancelling " + tasks.size() + " tasks for snapshot " + name);
for (Future f : tasks) {
// TODO Ideally we'd interrupt hbase threads when we cancel. However it seems that there
// are places in the HBase code where row/region locks are taken and not released in a
// finally block. Thus we cancel without interrupting. Cancellations will be slower to
// complete but we won't suffer from unreleased locks due to poor code discipline.
f.cancel(false);
}
// evict remaining tasks and futures from taskPool.
futures.clear();
while (taskPool.poll() != null) {
}
stop();
}
/**
* Abruptly shutdown the thread pool. Call when exiting a region server.
*/
void stop() {
if (this.stopped) return;
this.stopped = true;
this.executor.shutdown();
}
}
/**
* Create a default snapshot handler - uses a zookeeper based member controller.
* @param rss region server running the handler
* @throws KeeperException if the zookeeper cluster cannot be reached
*/
@Override
public void initialize(RegionServerServices rss) throws KeeperException {
this.rss = rss;
ZKWatcher zkw = rss.getZooKeeper();
this.memberRpcs =
new ZKProcedureMemberRpcs(zkw, SnapshotManager.ONLINE_SNAPSHOT_CONTROLLER_DESCRIPTION);
// read in the snapshot request configuration properties
Configuration conf = rss.getConfiguration();
long keepAlive = conf.getLong(SNAPSHOT_TIMEOUT_MILLIS_KEY, SNAPSHOT_TIMEOUT_MILLIS_DEFAULT);
int opThreads = conf.getInt(SNAPSHOT_REQUEST_THREADS_KEY, SNAPSHOT_REQUEST_THREADS_DEFAULT);
// create the actual snapshot procedure member
ThreadPoolExecutor pool =
ProcedureMember.defaultPool(rss.getServerName().toString(), opThreads, keepAlive);
this.member = new ProcedureMember(memberRpcs, pool, new SnapshotSubprocedureBuilder());
}
@Override
public String getProcedureSignature() {
return SnapshotManager.ONLINE_SNAPSHOT_CONTROLLER_DESCRIPTION;
}
}