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apache / cassandra / d3db33c008542c7044f3ed8c19f3a45679fcf52e / . / src / java / org / apache / cassandra / service / StorageProxy.java
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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.cassandra.service;
import java.io.IOException;
import java.lang.management.ManagementFactory;
import java.net.InetAddress;
import java.nio.ByteBuffer;
import java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import com.google.common.base.Predicate;
import com.google.common.cache.CacheLoader;
import com.google.common.collect.*;
import com.google.common.util.concurrent.Uninterruptibles;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.concurrent.Stage;
import org.apache.cassandra.concurrent.StageManager;
import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.config.Schema;
import org.apache.cassandra.db.*;
import org.apache.cassandra.db.filter.TombstoneOverwhelmingException;
import org.apache.cassandra.db.index.SecondaryIndex;
import org.apache.cassandra.db.index.SecondaryIndexSearcher;
import org.apache.cassandra.db.marshal.UUIDType;
import org.apache.cassandra.dht.AbstractBounds;
import org.apache.cassandra.dht.Bounds;
import org.apache.cassandra.dht.RingPosition;
import org.apache.cassandra.dht.Token;
import org.apache.cassandra.exceptions.*;
import org.apache.cassandra.gms.FailureDetector;
import org.apache.cassandra.gms.Gossiper;
import org.apache.cassandra.io.util.DataOutputBuffer;
import org.apache.cassandra.locator.AbstractReplicationStrategy;
import org.apache.cassandra.locator.IEndpointSnitch;
import org.apache.cassandra.locator.LocalStrategy;
import org.apache.cassandra.locator.TokenMetadata;
import org.apache.cassandra.metrics.*;
import org.apache.cassandra.net.*;
import org.apache.cassandra.net.MessagingService.Verb;
import org.apache.cassandra.service.paxos.*;
import org.apache.cassandra.tracing.Tracing;
import org.apache.cassandra.triggers.TriggerExecutor;
import org.apache.cassandra.utils.*;
public class StorageProxy implements StorageProxyMBean
{
public static final String MBEAN_NAME = "org.apache.cassandra.db:type=StorageProxy";
private static final Logger logger = LoggerFactory.getLogger(StorageProxy.class);
public static final String UNREACHABLE = "UNREACHABLE";
private static final WritePerformer standardWritePerformer;
private static final WritePerformer counterWritePerformer;
private static final WritePerformer counterWriteOnCoordinatorPerformer;
public static final StorageProxy instance = new StorageProxy();
private static volatile int maxHintsInProgress = 128 * FBUtilities.getAvailableProcessors();
private static final CacheLoader<InetAddress, AtomicInteger> hintsInProgress = new CacheLoader<InetAddress, AtomicInteger>()
{
public AtomicInteger load(InetAddress inetAddress)
{
return new AtomicInteger(0);
}
};
private static final ClientRequestMetrics readMetrics = new ClientRequestMetrics("Read");
private static final ClientRequestMetrics rangeMetrics = new ClientRequestMetrics("RangeSlice");
private static final ClientRequestMetrics writeMetrics = new ClientRequestMetrics("Write");
private static final CASClientRequestMetrics casWriteMetrics = new CASClientRequestMetrics("CASWrite");
private static final CASClientRequestMetrics casReadMetrics = new CASClientRequestMetrics("CASRead");
private static final double CONCURRENT_SUBREQUESTS_MARGIN = 0.10;
private StorageProxy() {}
static
{
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
try
{
mbs.registerMBean(instance, new ObjectName(MBEAN_NAME));
}
catch (Exception e)
{
throw new RuntimeException(e);
}
standardWritePerformer = new WritePerformer()
{
public void apply(IMutation mutation,
Iterable<InetAddress> targets,
AbstractWriteResponseHandler<IMutation> responseHandler,
String localDataCenter,
ConsistencyLevel consistency_level)
throws OverloadedException
{
assert mutation instanceof Mutation;
sendToHintedEndpoints((Mutation) mutation, targets, responseHandler, localDataCenter);
}
};
/*
* We execute counter writes in 2 places: either directly in the coordinator node if it is a replica, or
* in CounterMutationVerbHandler on a replica othewise. The write must be executed on the COUNTER_MUTATION stage
* but on the latter case, the verb handler already run on the COUNTER_MUTATION stage, so we must not execute the
* underlying on the stage otherwise we risk a deadlock. Hence two different performer.
*/
counterWritePerformer = new WritePerformer()
{
public void apply(IMutation mutation,
Iterable<InetAddress> targets,
AbstractWriteResponseHandler<IMutation> responseHandler,
String localDataCenter,
ConsistencyLevel consistencyLevel)
{
counterWriteTask(mutation, targets, responseHandler, localDataCenter).run();
}
};
counterWriteOnCoordinatorPerformer = new WritePerformer()
{
public void apply(IMutation mutation,
Iterable<InetAddress> targets,
AbstractWriteResponseHandler<IMutation> responseHandler,
String localDataCenter,
ConsistencyLevel consistencyLevel)
{
StageManager.getStage(Stage.COUNTER_MUTATION)
.execute(counterWriteTask(mutation, targets, responseHandler, localDataCenter));
}
};
}
/**
* Apply @param updates if and only if the current values in the row for @param key
* match the provided @param conditions. The algorithm is "raw" Paxos: that is, Paxos
* minus leader election -- any node in the cluster may propose changes for any row,
* which (that is, the row) is the unit of values being proposed, not single columns.
*
* The Paxos cohort is only the replicas for the given key, not the entire cluster.
* So we expect performance to be reasonable, but CAS is still intended to be used
* "when you really need it," not for all your updates.
*
* There are three phases to Paxos:
* 1. Prepare: the coordinator generates a ballot (timeUUID in our case) and asks replicas to (a) promise
* not to accept updates from older ballots and (b) tell us about the most recent update it has already
* accepted.
* 2. Accept: if a majority of replicas reply, the coordinator asks replicas to accept the value of the
* highest proposal ballot it heard about, or a new value if no in-progress proposals were reported.
* 3. Commit (Learn): if a majority of replicas acknowledge the accept request, we can commit the new
* value.
*
* Commit procedure is not covered in "Paxos Made Simple," and only briefly mentioned in "Paxos Made Live,"
* so here is our approach:
* 3a. The coordinator sends a commit message to all replicas with the ballot and value.
* 3b. Because of 1-2, this will be the highest-seen commit ballot. The replicas will note that,
* and send it with subsequent promise replies. This allows us to discard acceptance records
* for successfully committed replicas, without allowing incomplete proposals to commit erroneously
* later on.
*
* Note that since we are performing a CAS rather than a simple update, we perform a read (of committed
* values) between the prepare and accept phases. This gives us a slightly longer window for another
* coordinator to come along and trump our own promise with a newer one but is otherwise safe.
*
* @param keyspaceName the keyspace for the CAS
* @param cfName the column family for the CAS
* @param key the row key for the row to CAS
* @param request the conditions for the CAS to apply as well as the update to perform if the conditions hold.
* @param consistencyForPaxos the consistency for the paxos prepare and propose round. This can only be either SERIAL or LOCAL_SERIAL.
* @param consistencyForCommit the consistency for write done during the commit phase. This can be anything, except SERIAL or LOCAL_SERIAL.
*
* @return null if the operation succeeds in updating the row, or the current values corresponding to conditions.
* (since, if the CAS doesn't succeed, it means the current value do not match the conditions).
*/
public static ColumnFamily cas(String keyspaceName,
String cfName,
ByteBuffer key,
CASRequest request,
ConsistencyLevel consistencyForPaxos,
ConsistencyLevel consistencyForCommit,
ClientState state)
throws UnavailableException, IsBootstrappingException, RequestFailureException, RequestTimeoutException, InvalidRequestException
{
final long start = System.nanoTime();
int contentions = 0;
try
{
consistencyForPaxos.validateForCas();
consistencyForCommit.validateForCasCommit(keyspaceName);
CFMetaData metadata = Schema.instance.getCFMetaData(keyspaceName, cfName);
long timeout = TimeUnit.MILLISECONDS.toNanos(DatabaseDescriptor.getCasContentionTimeout());
while (System.nanoTime() - start < timeout)
{
// for simplicity, we'll do a single liveness check at the start of each attempt
Pair<List<InetAddress>, Integer> p = getPaxosParticipants(keyspaceName, key, consistencyForPaxos);
List<InetAddress> liveEndpoints = p.left;
int requiredParticipants = p.right;
final Pair<UUID, Integer> pair = beginAndRepairPaxos(start, key, metadata, liveEndpoints, requiredParticipants, consistencyForPaxos, consistencyForCommit, true, state);
final UUID ballot = pair.left;
contentions += pair.right;
// read the current values and check they validate the conditions
Tracing.trace("Reading existing values for CAS precondition");
long timestamp = System.currentTimeMillis();
ReadCommand readCommand = ReadCommand.create(keyspaceName, key, cfName, timestamp, request.readFilter());
List<Row> rows = read(Arrays.asList(readCommand), consistencyForPaxos == ConsistencyLevel.LOCAL_SERIAL
? ConsistencyLevel.LOCAL_QUORUM
: ConsistencyLevel.QUORUM);
ColumnFamily current = rows.get(0).cf;
if (!request.appliesTo(current))
{
Tracing.trace("CAS precondition does not match current values {}", current);
// We should not return null as this means success
casWriteMetrics.conditionNotMet.inc();
return current == null ? ArrayBackedSortedColumns.factory.create(metadata) : current;
}
// finish the paxos round w/ the desired updates
// TODO turn null updates into delete?
ColumnFamily updates = request.makeUpdates(current);
// Apply triggers to cas updates. A consideration here is that
// triggers emit Mutations, and so a given trigger implementation
// may generate mutations for partitions other than the one this
// paxos round is scoped for. In this case, TriggerExecutor will
// validate that the generated mutations are targetted at the same
// partition as the initial updates and reject (via an
// InvalidRequestException) any which aren't.
updates = TriggerExecutor.instance.execute(key, updates);
Commit proposal = Commit.newProposal(key, ballot, updates);
Tracing.trace("CAS precondition is met; proposing client-requested updates for {}", ballot);
if (proposePaxos(proposal, liveEndpoints, requiredParticipants, true, consistencyForPaxos))
{
commitPaxos(proposal, consistencyForCommit, true);
Tracing.trace("CAS successful");
return null;
}
Tracing.trace("Paxos proposal not accepted (pre-empted by a higher ballot)");
contentions++;
Uninterruptibles.sleepUninterruptibly(ThreadLocalRandom.current().nextInt(100), TimeUnit.MILLISECONDS);
// continue to retry
}
throw new WriteTimeoutException(WriteType.CAS, consistencyForPaxos, 0, consistencyForPaxos.blockFor(Keyspace.open(keyspaceName)));
}
catch (WriteTimeoutException|ReadTimeoutException e)
{
casWriteMetrics.timeouts.mark();
throw e;
}
catch (WriteFailureException|ReadFailureException e)
{
casWriteMetrics.failures.mark();
throw e;
}
catch(UnavailableException e)
{
casWriteMetrics.unavailables.mark();
throw e;
}
finally
{
if(contentions > 0)
casWriteMetrics.contention.update(contentions);
casWriteMetrics.addNano(System.nanoTime() - start);
}
}
private static Predicate<InetAddress> sameDCPredicateFor(final String dc)
{
final IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
return new Predicate<InetAddress>()
{
public boolean apply(InetAddress host)
{
return dc.equals(snitch.getDatacenter(host));
}
};
}
private static Pair<List<InetAddress>, Integer> getPaxosParticipants(String keyspaceName, ByteBuffer key, ConsistencyLevel consistencyForPaxos) throws UnavailableException
{
Token tk = StorageService.getPartitioner().getToken(key);
List<InetAddress> naturalEndpoints = StorageService.instance.getNaturalEndpoints(keyspaceName, tk);
Collection<InetAddress> pendingEndpoints = StorageService.instance.getTokenMetadata().pendingEndpointsFor(tk, keyspaceName);
if (consistencyForPaxos == ConsistencyLevel.LOCAL_SERIAL)
{
// Restrict naturalEndpoints and pendingEndpoints to node in the local DC only
String localDc = DatabaseDescriptor.getEndpointSnitch().getDatacenter(FBUtilities.getBroadcastAddress());
Predicate<InetAddress> isLocalDc = sameDCPredicateFor(localDc);
naturalEndpoints = ImmutableList.copyOf(Iterables.filter(naturalEndpoints, isLocalDc));
pendingEndpoints = ImmutableList.copyOf(Iterables.filter(pendingEndpoints, isLocalDc));
}
int participants = pendingEndpoints.size() + naturalEndpoints.size();
int requiredParticipants = participants / 2 + 1; // See CASSANDRA-8346, CASSANDRA-833
List<InetAddress> liveEndpoints = ImmutableList.copyOf(Iterables.filter(Iterables.concat(naturalEndpoints, pendingEndpoints), IAsyncCallback.isAlive));
if (liveEndpoints.size() < requiredParticipants)
throw new UnavailableException(consistencyForPaxos, requiredParticipants, liveEndpoints.size());
// We cannot allow CAS operations with 2 or more pending endpoints, see #8346.
// Note that we fake an impossible number of required nodes in the unavailable exception
// to nail home the point that it's an impossible operation no matter how many nodes are live.
if (pendingEndpoints.size() > 1)
throw new UnavailableException(String.format("Cannot perform LWT operation as there is more than one (%d) pending range movement", pendingEndpoints.size()),
consistencyForPaxos,
participants + 1,
liveEndpoints.size());
return Pair.create(liveEndpoints, requiredParticipants);
}
/**
* begin a Paxos session by sending a prepare request and completing any in-progress requests seen in the replies
*
* @return the Paxos ballot promised by the replicas if no in-progress requests were seen and a quorum of
* nodes have seen the mostRecentCommit. Otherwise, return null.
*/
private static Pair<UUID, Integer> beginAndRepairPaxos(long start,
ByteBuffer key,
CFMetaData metadata,
List<InetAddress> liveEndpoints,
int requiredParticipants,
ConsistencyLevel consistencyForPaxos,
ConsistencyLevel consistencyForCommit,
final boolean isWrite,
ClientState state)
throws WriteTimeoutException, WriteFailureException
{
long timeout = TimeUnit.MILLISECONDS.toNanos(DatabaseDescriptor.getCasContentionTimeout());
PrepareCallback summary = null;
int contentions = 0;
while (System.nanoTime() - start < timeout)
{
// We want a timestamp that is guaranteed to be unique for that node (so that the ballot is globally unique), but if we've got a prepare rejected
// already we also want to make sure we pick a timestamp that has a chance to be promised, i.e. one that is greater that the most recently known
// in progress (#5667). Lastly, we don't want to use a timestamp that is older than the last one assigned by ClientState or operations may appear
// out-of-order (#7801).
long minTimestampMicrosToUse = summary == null ? Long.MIN_VALUE : 1 + UUIDGen.microsTimestamp(summary.mostRecentInProgressCommit.ballot);
long ballotMicros = state.getTimestamp(minTimestampMicrosToUse);
UUID ballot = UUIDGen.getTimeUUIDFromMicros(ballotMicros);
// prepare
Tracing.trace("Preparing {}", ballot);
Commit toPrepare = Commit.newPrepare(key, metadata, ballot);
summary = preparePaxos(toPrepare, liveEndpoints, requiredParticipants, consistencyForPaxos);
if (!summary.promised)
{
Tracing.trace("Some replicas have already promised a higher ballot than ours; aborting");
contentions++;
// sleep a random amount to give the other proposer a chance to finish
Uninterruptibles.sleepUninterruptibly(ThreadLocalRandom.current().nextInt(100), TimeUnit.MILLISECONDS);
continue;
}
Commit inProgress = summary.mostRecentInProgressCommitWithUpdate;
Commit mostRecent = summary.mostRecentCommit;
// If we have an in-progress ballot greater than the MRC we know, then it's an in-progress round that
// needs to be completed, so do it.
if (!inProgress.update.isEmpty() && inProgress.isAfter(mostRecent))
{
Tracing.trace("Finishing incomplete paxos round {}", inProgress);
if(isWrite)
casWriteMetrics.unfinishedCommit.inc();
else
casReadMetrics.unfinishedCommit.inc();
Commit refreshedInProgress = Commit.newProposal(inProgress.key, ballot, inProgress.update);
if (proposePaxos(refreshedInProgress, liveEndpoints, requiredParticipants, false, consistencyForPaxos))
{
try
{
commitPaxos(refreshedInProgress, consistencyForCommit, false);
}
catch (WriteTimeoutException e)
{
// We're still doing preparation for the paxos rounds, so we want to use the CAS (see CASSANDRA-8672)
throw new WriteTimeoutException(WriteType.CAS, e.consistency, e.received, e.blockFor);
}
}
else
{
Tracing.trace("Some replicas have already promised a higher ballot than ours; aborting");
// sleep a random amount to give the other proposer a chance to finish
contentions++;
Uninterruptibles.sleepUninterruptibly(ThreadLocalRandom.current().nextInt(100), TimeUnit.MILLISECONDS);
}
continue;
}
// To be able to propose our value on a new round, we need a quorum of replica to have learn the previous one. Why is explained at:
// https://issues.apache.org/jira/browse/CASSANDRA-5062?focusedCommentId=13619810&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13619810)
// Since we waited for quorum nodes, if some of them haven't seen the last commit (which may just be a timing issue, but may also
// mean we lost messages), we pro-actively "repair" those nodes, and retry.
Iterable<InetAddress> missingMRC = summary.replicasMissingMostRecentCommit();
if (Iterables.size(missingMRC) > 0)
{
Tracing.trace("Repairing replicas that missed the most recent commit");
sendCommit(mostRecent, missingMRC);
// TODO: provided commits don't invalid the prepare we just did above (which they don't), we could just wait
// for all the missingMRC to acknowledge this commit and then move on with proposing our value. But that means
// adding the ability to have commitPaxos block, which is exactly CASSANDRA-5442 will do. So once we have that
// latter ticket, we can pass CL.ALL to the commit above and remove the 'continue'.
continue;
}
return Pair.create(ballot, contentions);
}
throw new WriteTimeoutException(WriteType.CAS, consistencyForPaxos, 0, consistencyForPaxos.blockFor(Keyspace.open(metadata.ksName)));
}
/**
* Unlike commitPaxos, this does not wait for replies
*/
private static void sendCommit(Commit commit, Iterable<InetAddress> replicas)
{
MessageOut<Commit> message = new MessageOut<Commit>(MessagingService.Verb.PAXOS_COMMIT, commit, Commit.serializer);
for (InetAddress target : replicas)
MessagingService.instance().sendOneWay(message, target);
}
private static PrepareCallback preparePaxos(Commit toPrepare, List<InetAddress> endpoints, int requiredParticipants, ConsistencyLevel consistencyForPaxos)
throws WriteTimeoutException
{
PrepareCallback callback = new PrepareCallback(toPrepare.key, toPrepare.update.metadata(), requiredParticipants, consistencyForPaxos);
MessageOut<Commit> message = new MessageOut<Commit>(MessagingService.Verb.PAXOS_PREPARE, toPrepare, Commit.serializer);
for (InetAddress target : endpoints)
MessagingService.instance().sendRR(message, target, callback);
callback.await();
return callback;
}
private static boolean proposePaxos(Commit proposal, List<InetAddress> endpoints, int requiredParticipants, boolean timeoutIfPartial, ConsistencyLevel consistencyLevel)
throws WriteTimeoutException
{
ProposeCallback callback = new ProposeCallback(endpoints.size(), requiredParticipants, !timeoutIfPartial, consistencyLevel);
MessageOut<Commit> message = new MessageOut<Commit>(MessagingService.Verb.PAXOS_PROPOSE, proposal, Commit.serializer);
for (InetAddress target : endpoints)
MessagingService.instance().sendRR(message, target, callback);
callback.await();
if (callback.isSuccessful())
return true;
if (timeoutIfPartial && !callback.isFullyRefused())
throw new WriteTimeoutException(WriteType.CAS, consistencyLevel, callback.getAcceptCount(), requiredParticipants);
return false;
}
private static void commitPaxos(Commit proposal, ConsistencyLevel consistencyLevel, boolean shouldHint) throws WriteTimeoutException
{
boolean shouldBlock = consistencyLevel != ConsistencyLevel.ANY;
Keyspace keyspace = Keyspace.open(proposal.update.metadata().ksName);
Token tk = StorageService.getPartitioner().getToken(proposal.key);
List<InetAddress> naturalEndpoints = StorageService.instance.getNaturalEndpoints(keyspace.getName(), tk);
Collection<InetAddress> pendingEndpoints = StorageService.instance.getTokenMetadata().pendingEndpointsFor(tk, keyspace.getName());
AbstractWriteResponseHandler<Commit> responseHandler = null;
if (shouldBlock)
{
AbstractReplicationStrategy rs = keyspace.getReplicationStrategy();
responseHandler = rs.getWriteResponseHandler(naturalEndpoints, pendingEndpoints, consistencyLevel, null, WriteType.SIMPLE);
}
MessageOut<Commit> message = new MessageOut<Commit>(MessagingService.Verb.PAXOS_COMMIT, proposal, Commit.serializer);
for (InetAddress destination : Iterables.concat(naturalEndpoints, pendingEndpoints))
{
if (FailureDetector.instance.isAlive(destination))
{
if (shouldBlock)
{
if (destination.equals(FBUtilities.getBroadcastAddress()))
commitPaxosLocal(message, responseHandler);
else
MessagingService.instance().sendRR(message, destination, responseHandler, shouldHint);
}
else
{
MessagingService.instance().sendOneWay(message, destination);
}
}
else if (shouldHint)
{
submitHint(proposal.makeMutation(), destination, null);
}
}
if (shouldBlock)
responseHandler.get();
}
/**
* Commit a PAXOS task locally, and if the task times out rather then submitting a real hint
* submit a fake one that executes immediately on the mutation stage, but generates the necessary backpressure
* signal for hints
*/
private static void commitPaxosLocal(final MessageOut<Commit> message, final AbstractWriteResponseHandler responseHandler)
{
StageManager.getStage(MessagingService.verbStages.get(MessagingService.Verb.PAXOS_COMMIT)).maybeExecuteImmediately(new LocalMutationRunnable()
{
public void runMayThrow()
{
PaxosState.commit(message.payload);
if (responseHandler != null)
responseHandler.response(null);
}
@Override
protected Verb verb()
{
return MessagingService.Verb.PAXOS_COMMIT;
}
});
}
/**
* Use this method to have these Mutations applied
* across all replicas. This method will take care
* of the possibility of a replica being down and hint
* the data across to some other replica.
*
* @param mutations the mutations to be applied across the replicas
* @param consistency_level the consistency level for the operation
*/
public static void mutate(Collection<? extends IMutation> mutations, ConsistencyLevel consistency_level)
throws UnavailableException, OverloadedException, WriteTimeoutException, WriteFailureException
{
Tracing.trace("Determining replicas for mutation");
final String localDataCenter = DatabaseDescriptor.getEndpointSnitch().getDatacenter(FBUtilities.getBroadcastAddress());
long startTime = System.nanoTime();
List<AbstractWriteResponseHandler<IMutation>> responseHandlers = new ArrayList<>(mutations.size());
try
{
for (IMutation mutation : mutations)
{
if (mutation instanceof CounterMutation)
{
responseHandlers.add(mutateCounter((CounterMutation)mutation, localDataCenter));
}
else
{
WriteType wt = mutations.size() <= 1 ? WriteType.SIMPLE : WriteType.UNLOGGED_BATCH;
responseHandlers.add(performWrite(mutation, consistency_level, localDataCenter, standardWritePerformer, null, wt));
}
}
// wait for writes. throws TimeoutException if necessary
for (AbstractWriteResponseHandler<IMutation> responseHandler : responseHandlers)
{
responseHandler.get();
}
}
catch (WriteTimeoutException|WriteFailureException ex)
{
if (consistency_level == ConsistencyLevel.ANY)
{
hintMutations(mutations);
}
else
{
if (ex instanceof WriteFailureException)
{
writeMetrics.failures.mark();
WriteFailureException fe = (WriteFailureException)ex;
Tracing.trace("Write failure; received {} of {} required replies, failed {} requests",
fe.received, fe.blockFor, fe.failures);
}
else
{
writeMetrics.timeouts.mark();
WriteTimeoutException te = (WriteTimeoutException)ex;
Tracing.trace("Write timeout; received {} of {} required replies", te.received, te.blockFor);
}
throw ex;
}
}
catch (UnavailableException e)
{
writeMetrics.unavailables.mark();
Tracing.trace("Unavailable");
throw e;
}
catch (OverloadedException e)
{
writeMetrics.unavailables.mark();
Tracing.trace("Overloaded");
throw e;
}
finally
{
writeMetrics.addNano(System.nanoTime() - startTime);
}
}
/** hint all the mutations (except counters, which can't be safely retried). This means
* we'll re-hint any successful ones; doesn't seem worth it to track individual success
* just for this unusual case.
* @param mutations the mutations that require hints
*/
private static void hintMutations(Collection<? extends IMutation> mutations)
{
for (IMutation mutation : mutations)
{
if (mutation instanceof CounterMutation)
continue;
Token tk = StorageService.getPartitioner().getToken(mutation.key());
List<InetAddress> naturalEndpoints = StorageService.instance.getNaturalEndpoints(mutation.getKeyspaceName(), tk);
Collection<InetAddress> pendingEndpoints = StorageService.instance.getTokenMetadata().pendingEndpointsFor(tk, mutation.getKeyspaceName());
for (InetAddress target : Iterables.concat(naturalEndpoints, pendingEndpoints))
{
// local writes can timeout, but cannot be dropped (see LocalMutationRunnable and
// CASSANDRA-6510), so there is no need to hint or retry
if (!target.equals(FBUtilities.getBroadcastAddress()) && shouldHint(target))
submitHint((Mutation) mutation, target, null);
}
}
Tracing.trace("Wrote hint to satisfy CL.ANY after no replicas acknowledged the write");
}
@SuppressWarnings("unchecked")
public static void mutateWithTriggers(Collection<? extends IMutation> mutations,
ConsistencyLevel consistencyLevel,
boolean mutateAtomically)
throws WriteTimeoutException, WriteFailureException, UnavailableException, OverloadedException, InvalidRequestException
{
Collection<Mutation> augmented = TriggerExecutor.instance.execute(mutations);
if (augmented != null)
mutateAtomically(augmented, consistencyLevel);
else if (mutateAtomically)
mutateAtomically((Collection<Mutation>) mutations, consistencyLevel);
else
mutate(mutations, consistencyLevel);
}
/**
* See mutate. Adds additional steps before and after writing a batch.
* Before writing the batch (but after doing availability check against the FD for the row replicas):
* write the entire batch to a batchlog elsewhere in the cluster.
* After: remove the batchlog entry (after writing hints for the batch rows, if necessary).
*
* @param mutations the Mutations to be applied across the replicas
* @param consistency_level the consistency level for the operation
*/
public static void mutateAtomically(Collection<Mutation> mutations, ConsistencyLevel consistency_level)
throws UnavailableException, OverloadedException, WriteTimeoutException
{
Tracing.trace("Determining replicas for atomic batch");
long startTime = System.nanoTime();
List<WriteResponseHandlerWrapper> wrappers = new ArrayList<WriteResponseHandlerWrapper>(mutations.size());
String localDataCenter = DatabaseDescriptor.getEndpointSnitch().getDatacenter(FBUtilities.getBroadcastAddress());
try
{
// add a handler for each mutation - includes checking availability, but doesn't initiate any writes, yet
for (Mutation mutation : mutations)
{
WriteResponseHandlerWrapper wrapper = wrapResponseHandler(mutation, consistency_level, WriteType.BATCH);
// exit early if we can't fulfill the CL at this time.
wrapper.handler.assureSufficientLiveNodes();
wrappers.add(wrapper);
}
// write to the batchlog
Collection<InetAddress> batchlogEndpoints = getBatchlogEndpoints(localDataCenter, consistency_level);
UUID batchUUID = UUIDGen.getTimeUUID();
syncWriteToBatchlog(mutations, batchlogEndpoints, batchUUID);
// now actually perform the writes and wait for them to complete
syncWriteBatchedMutations(wrappers, localDataCenter);
// remove the batchlog entries asynchronously
asyncRemoveFromBatchlog(batchlogEndpoints, batchUUID);
}
catch (UnavailableException e)
{
writeMetrics.unavailables.mark();
Tracing.trace("Unavailable");
throw e;
}
catch (WriteTimeoutException e)
{
writeMetrics.timeouts.mark();
Tracing.trace("Write timeout; received {} of {} required replies", e.received, e.blockFor);
throw e;
}
catch (WriteFailureException e)
{
writeMetrics.failures.mark();
Tracing.trace("Write failure; received {} of {} required replies", e.received, e.blockFor);
throw e;
}
finally
{
writeMetrics.addNano(System.nanoTime() - startTime);
}
}
private static void syncWriteToBatchlog(Collection<Mutation> mutations, Collection<InetAddress> endpoints, UUID uuid)
throws WriteTimeoutException, WriteFailureException
{
AbstractWriteResponseHandler<IMutation> handler = new WriteResponseHandler<>(endpoints,
Collections.<InetAddress>emptyList(),
ConsistencyLevel.ONE,
Keyspace.open(SystemKeyspace.NAME),
null,
WriteType.BATCH_LOG);
MessageOut<Mutation> message = BatchlogManager.getBatchlogMutationFor(mutations, uuid, MessagingService.current_version)
.createMessage();
for (InetAddress target : endpoints)
{
int targetVersion = MessagingService.instance().getVersion(target);
if (target.equals(FBUtilities.getBroadcastAddress()))
{
insertLocal(message.payload, handler);
}
else if (targetVersion == MessagingService.current_version)
{
MessagingService.instance().sendRR(message, target, handler, false);
}
else
{
MessagingService.instance().sendRR(BatchlogManager.getBatchlogMutationFor(mutations, uuid, targetVersion)
.createMessage(),
target,
handler,
false);
}
}
handler.get();
}
private static void asyncRemoveFromBatchlog(Collection<InetAddress> endpoints, UUID uuid)
{
AbstractWriteResponseHandler<IMutation> handler = new WriteResponseHandler<>(endpoints,
Collections.<InetAddress>emptyList(),
ConsistencyLevel.ANY,
Keyspace.open(SystemKeyspace.NAME),
null,
WriteType.SIMPLE);
Mutation mutation = new Mutation(SystemKeyspace.NAME, UUIDType.instance.decompose(uuid));
mutation.delete(SystemKeyspace.BATCHLOG, FBUtilities.timestampMicros());
MessageOut<Mutation> message = mutation.createMessage();
for (InetAddress target : endpoints)
{
if (target.equals(FBUtilities.getBroadcastAddress()))
insertLocal(message.payload, handler);
else
MessagingService.instance().sendRR(message, target, handler, false);
}
}
private static void syncWriteBatchedMutations(List<WriteResponseHandlerWrapper> wrappers, String localDataCenter)
throws WriteTimeoutException, OverloadedException
{
for (WriteResponseHandlerWrapper wrapper : wrappers)
{
Iterable<InetAddress> endpoints = Iterables.concat(wrapper.handler.naturalEndpoints, wrapper.handler.pendingEndpoints);
sendToHintedEndpoints(wrapper.mutation, endpoints, wrapper.handler, localDataCenter);
}
for (WriteResponseHandlerWrapper wrapper : wrappers)
wrapper.handler.get();
}
/**
* Perform the write of a mutation given a WritePerformer.
* Gather the list of write endpoints, apply locally and/or forward the mutation to
* said write endpoint (deletaged to the actual WritePerformer) and wait for the
* responses based on consistency level.
*
* @param mutation the mutation to be applied
* @param consistency_level the consistency level for the write operation
* @param performer the WritePerformer in charge of appliying the mutation
* given the list of write endpoints (either standardWritePerformer for
* standard writes or counterWritePerformer for counter writes).
* @param callback an optional callback to be run if and when the write is
* successful.
*/
public static AbstractWriteResponseHandler<IMutation> performWrite(IMutation mutation,
ConsistencyLevel consistency_level,
String localDataCenter,
WritePerformer performer,
Runnable callback,
WriteType writeType)
throws UnavailableException, OverloadedException
{
String keyspaceName = mutation.getKeyspaceName();
AbstractReplicationStrategy rs = Keyspace.open(keyspaceName).getReplicationStrategy();
Token tk = StorageService.getPartitioner().getToken(mutation.key());
List<InetAddress> naturalEndpoints = StorageService.instance.getNaturalEndpoints(keyspaceName, tk);
Collection<InetAddress> pendingEndpoints = StorageService.instance.getTokenMetadata().pendingEndpointsFor(tk, keyspaceName);
AbstractWriteResponseHandler<IMutation> responseHandler = rs.getWriteResponseHandler(naturalEndpoints, pendingEndpoints, consistency_level, callback, writeType);
// exit early if we can't fulfill the CL at this time
responseHandler.assureSufficientLiveNodes();
performer.apply(mutation, Iterables.concat(naturalEndpoints, pendingEndpoints), responseHandler, localDataCenter, consistency_level);
return responseHandler;
}
// same as above except does not initiate writes (but does perform availability checks).
private static WriteResponseHandlerWrapper wrapResponseHandler(Mutation mutation, ConsistencyLevel consistency_level, WriteType writeType)
{
AbstractReplicationStrategy rs = Keyspace.open(mutation.getKeyspaceName()).getReplicationStrategy();
String keyspaceName = mutation.getKeyspaceName();
Token tk = StorageService.getPartitioner().getToken(mutation.key());
List<InetAddress> naturalEndpoints = StorageService.instance.getNaturalEndpoints(keyspaceName, tk);
Collection<InetAddress> pendingEndpoints = StorageService.instance.getTokenMetadata().pendingEndpointsFor(tk, keyspaceName);
AbstractWriteResponseHandler<IMutation> responseHandler = rs.getWriteResponseHandler(naturalEndpoints, pendingEndpoints, consistency_level, null, writeType);
return new WriteResponseHandlerWrapper(responseHandler, mutation);
}
// used by atomic_batch_mutate to decouple availability check from the write itself, caches consistency level and endpoints.
private static class WriteResponseHandlerWrapper
{
final AbstractWriteResponseHandler<IMutation> handler;
final Mutation mutation;
WriteResponseHandlerWrapper(AbstractWriteResponseHandler<IMutation> handler, Mutation mutation)
{
this.handler = handler;
this.mutation = mutation;
}
}
/*
* Replicas are picked manually:
* - replicas should be alive according to the failure detector
* - replicas should be in the local datacenter
* - choose min(2, number of qualifying candiates above)
* - allow the local node to be the only replica only if it's a single-node DC
*/
private static Collection<InetAddress> getBatchlogEndpoints(String localDataCenter, ConsistencyLevel consistencyLevel)
throws UnavailableException
{
TokenMetadata.Topology topology = StorageService.instance.getTokenMetadata().cachedOnlyTokenMap().getTopology();
Multimap<String, InetAddress> localEndpoints = HashMultimap.create(topology.getDatacenterRacks().get(localDataCenter));
String localRack = DatabaseDescriptor.getEndpointSnitch().getRack(FBUtilities.getBroadcastAddress());
Collection<InetAddress> chosenEndpoints = new BatchlogManager.EndpointFilter(localRack, localEndpoints).filter();
if (chosenEndpoints.isEmpty())
{
if (consistencyLevel == ConsistencyLevel.ANY)
return Collections.singleton(FBUtilities.getBroadcastAddress());
throw new UnavailableException(ConsistencyLevel.ONE, 1, 0);
}
return chosenEndpoints;
}
/**
* Send the mutations to the right targets, write it locally if it corresponds or writes a hint when the node
* is not available.
*
* Note about hints:
* <pre>
* {@code
* | Hinted Handoff | Consist. Level |
* | on | >=1 | --> wait for hints. We DO NOT notify the handler with handler.response() for hints;
* | on | ANY | --> wait for hints. Responses count towards consistency.
* | off | >=1 | --> DO NOT fire hints. And DO NOT wait for them to complete.
* | off | ANY | --> DO NOT fire hints. And DO NOT wait for them to complete.
* }
* </pre>
*
* @throws OverloadedException if the hints cannot be written/enqueued
*/
public static void sendToHintedEndpoints(final Mutation mutation,
Iterable<InetAddress> targets,
AbstractWriteResponseHandler<IMutation> responseHandler,
String localDataCenter)
throws OverloadedException
{
// extra-datacenter replicas, grouped by dc
Map<String, Collection<InetAddress>> dcGroups = null;
// only need to create a Message for non-local writes
MessageOut<Mutation> message = null;
boolean insertLocal = false;
for (InetAddress destination : targets)
{
checkHintOverload(destination);
if (FailureDetector.instance.isAlive(destination))
{
if (destination.equals(FBUtilities.getBroadcastAddress()))
{
insertLocal = true;
} else
{
// belongs on a different server
if (message == null)
message = mutation.createMessage();
String dc = DatabaseDescriptor.getEndpointSnitch().getDatacenter(destination);
// direct writes to local DC or old Cassandra versions
// (1.1 knows how to forward old-style String message IDs; updated to int in 2.0)
if (localDataCenter.equals(dc))
{
MessagingService.instance().sendRR(message, destination, responseHandler, true);
} else
{
Collection<InetAddress> messages = (dcGroups != null) ? dcGroups.get(dc) : null;
if (messages == null)
{
messages = new ArrayList<InetAddress>(3); // most DCs will have <= 3 replicas
if (dcGroups == null)
dcGroups = new HashMap<String, Collection<InetAddress>>();
dcGroups.put(dc, messages);
}
messages.add(destination);
}
}
} else
{
if (!shouldHint(destination))
continue;
// Schedule a local hint
submitHint(mutation, destination, responseHandler);
}
}
if (insertLocal)
insertLocal(mutation, responseHandler);
if (dcGroups != null)
{
// for each datacenter, send the message to one node to relay the write to other replicas
if (message == null)
message = mutation.createMessage();
for (Collection<InetAddress> dcTargets : dcGroups.values())
sendMessagesToNonlocalDC(message, dcTargets, responseHandler);
}
}
private static void checkHintOverload(InetAddress destination) throws OverloadedException
{
// avoid OOMing due to excess hints. we need to do this check even for "live" nodes, since we can
// still generate hints for those if it's overloaded or simply dead but not yet known-to-be-dead.
// The idea is that if we have over maxHintsInProgress hints in flight, this is probably due to
// a small number of nodes causing problems, so we should avoid shutting down writes completely to
// healthy nodes. Any node with no hintsInProgress is considered healthy.
if (StorageMetrics.totalHintsInProgress.getCount() > maxHintsInProgress
&& (getHintsInProgressFor(destination).get() > 0 && shouldHint(destination)))
{
throw new OverloadedException("Too many in flight hints: " + StorageMetrics.totalHintsInProgress.getCount() +
" destination: " + destination +
" destination hints: " + getHintsInProgressFor(destination).get());
}
}
private static AtomicInteger getHintsInProgressFor(InetAddress destination)
{
try
{
return hintsInProgress.load(destination);
}
catch (Exception e)
{
throw new AssertionError(e);
}
}
public static Future<Void> submitHint(final Mutation mutation,
final InetAddress target,
final AbstractWriteResponseHandler<IMutation> responseHandler)
{
// local write that time out should be handled by LocalMutationRunnable
assert !target.equals(FBUtilities.getBroadcastAddress()) : target;
HintRunnable runnable = new HintRunnable(target)
{
public void runMayThrow()
{
int ttl = HintedHandOffManager.calculateHintTTL(mutation);
if (ttl > 0)
{
logger.trace("Adding hint for {}", target);
writeHintForMutation(mutation, System.currentTimeMillis(), ttl, target);
// Notify the handler only for CL == ANY
if (responseHandler != null && responseHandler.consistencyLevel == ConsistencyLevel.ANY)
responseHandler.response(null);
} else
{
logger.debug("Skipped writing hint for {} (ttl {})", target, ttl);
}
}
};
return submitHint(runnable);
}
private static Future<Void> submitHint(HintRunnable runnable)
{
StorageMetrics.totalHintsInProgress.inc();
getHintsInProgressFor(runnable.target).incrementAndGet();
return (Future<Void>) StageManager.getStage(Stage.MUTATION).submit(runnable);
}
/**
* @param now current time in milliseconds - relevant for hint replay handling of truncated CFs
*/
public static void writeHintForMutation(Mutation mutation, long now, int ttl, InetAddress target)
{
assert ttl > 0;
UUID hostId = StorageService.instance.getTokenMetadata().getHostId(target);
if (hostId != null)
{
HintedHandOffManager.instance.hintFor(mutation, now, ttl, Pair.create(target, hostId)).apply();
StorageMetrics.totalHints.inc();
}
else
logger.debug("Discarding hint for endpoint not part of ring: {}", target);
}
private static void sendMessagesToNonlocalDC(MessageOut<? extends IMutation> message,
Collection<InetAddress> targets,
AbstractWriteResponseHandler<IMutation> handler)
{
Iterator<InetAddress> iter = targets.iterator();
InetAddress target = iter.next();
// Add the other destinations of the same message as a FORWARD_HEADER entry
try (DataOutputBuffer out = new DataOutputBuffer())
{
out.writeInt(targets.size() - 1);
while (iter.hasNext())
{
InetAddress destination = iter.next();
CompactEndpointSerializationHelper.serialize(destination, out);
int id = MessagingService.instance().addCallback(handler,
message,
destination,
message.getTimeout(),
handler.consistencyLevel,
true);
out.writeInt(id);
logger.trace("Adding FWD message to {}@{}", id, destination);
}
message = message.withParameter(Mutation.FORWARD_TO, out.getData());
// send the combined message + forward headers
int id = MessagingService.instance().sendRR(message, target, handler, true);
logger.trace("Sending message to {}@{}", id, target);
}
catch (IOException e)
{
// DataOutputBuffer is in-memory, doesn't throw IOException
throw new AssertionError(e);
}
}
private static void insertLocal(final Mutation mutation, final AbstractWriteResponseHandler<IMutation> responseHandler)
{
StageManager.getStage(Stage.MUTATION).maybeExecuteImmediately(new LocalMutationRunnable()
{
public void runMayThrow()
{
try
{
mutation.apply();
responseHandler.response(null);
}
catch (Exception ex)
{
logger.error("Failed to apply mutation locally : {}", ex.getMessage());
responseHandler.onFailure(FBUtilities.getBroadcastAddress());
}
}
@Override
protected Verb verb()
{
return MessagingService.Verb.MUTATION;
}
});
}
/**
* Handle counter mutation on the coordinator host.
*
* A counter mutation needs to first be applied to a replica (that we'll call the leader for the mutation) before being
* replicated to the other endpoint. To achieve so, there is two case:
* 1) the coordinator host is a replica: we proceed to applying the update locally and replicate throug
* applyCounterMutationOnCoordinator
* 2) the coordinator is not a replica: we forward the (counter)mutation to a chosen replica (that will proceed through
* applyCounterMutationOnLeader upon receive) and wait for its acknowledgment.
*
* Implementation note: We check if we can fulfill the CL on the coordinator host even if he is not a replica to allow
* quicker response and because the WriteResponseHandlers don't make it easy to send back an error. We also always gather
* the write latencies at the coordinator node to make gathering point similar to the case of standard writes.
*/
public static AbstractWriteResponseHandler<IMutation> mutateCounter(CounterMutation cm, String localDataCenter) throws UnavailableException, OverloadedException
{
InetAddress endpoint = findSuitableEndpoint(cm.getKeyspaceName(), cm.key(), localDataCenter, cm.consistency());
if (endpoint.equals(FBUtilities.getBroadcastAddress()))
{
return applyCounterMutationOnCoordinator(cm, localDataCenter);
}
else
{
// Exit now if we can't fulfill the CL here instead of forwarding to the leader replica
String keyspaceName = cm.getKeyspaceName();
AbstractReplicationStrategy rs = Keyspace.open(keyspaceName).getReplicationStrategy();
Token tk = StorageService.getPartitioner().getToken(cm.key());
List<InetAddress> naturalEndpoints = StorageService.instance.getNaturalEndpoints(keyspaceName, tk);
Collection<InetAddress> pendingEndpoints = StorageService.instance.getTokenMetadata().pendingEndpointsFor(tk, keyspaceName);
rs.getWriteResponseHandler(naturalEndpoints, pendingEndpoints, cm.consistency(), null, WriteType.COUNTER).assureSufficientLiveNodes();
// Forward the actual update to the chosen leader replica
AbstractWriteResponseHandler<IMutation> responseHandler = new WriteResponseHandler<>(endpoint, WriteType.COUNTER);
Tracing.trace("Enqueuing counter update to {}", endpoint);
MessagingService.instance().sendRR(cm.makeMutationMessage(), endpoint, responseHandler, false);
return responseHandler;
}
}
/**
* Find a suitable replica as leader for counter update.
* For now, we pick a random replica in the local DC (or ask the snitch if
* there is no replica alive in the local DC).
* TODO: if we track the latency of the counter writes (which makes sense
* contrarily to standard writes since there is a read involved), we could
* trust the dynamic snitch entirely, which may be a better solution. It
* is unclear we want to mix those latencies with read latencies, so this
* may be a bit involved.
*/
private static InetAddress findSuitableEndpoint(String keyspaceName, ByteBuffer key, String localDataCenter, ConsistencyLevel cl) throws UnavailableException
{
Keyspace keyspace = Keyspace.open(keyspaceName);
IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
List<InetAddress> endpoints = StorageService.instance.getLiveNaturalEndpoints(keyspace, key);
if (endpoints.isEmpty())
// TODO have a way to compute the consistency level
throw new UnavailableException(cl, cl.blockFor(keyspace), 0);
List<InetAddress> localEndpoints = new ArrayList<InetAddress>();
for (InetAddress endpoint : endpoints)
{
if (snitch.getDatacenter(endpoint).equals(localDataCenter))
localEndpoints.add(endpoint);
}
if (localEndpoints.isEmpty())
{
// No endpoint in local DC, pick the closest endpoint according to the snitch
snitch.sortByProximity(FBUtilities.getBroadcastAddress(), endpoints);
return endpoints.get(0);
}
else
{
return localEndpoints.get(ThreadLocalRandom.current().nextInt(localEndpoints.size()));
}
}
// Must be called on a replica of the mutation. This replica becomes the
// leader of this mutation.
public static AbstractWriteResponseHandler<IMutation> applyCounterMutationOnLeader(CounterMutation cm, String localDataCenter, Runnable callback)
throws UnavailableException, OverloadedException
{
return performWrite(cm, cm.consistency(), localDataCenter, counterWritePerformer, callback, WriteType.COUNTER);
}
// Same as applyCounterMutationOnLeader but must with the difference that it use the MUTATION stage to execute the write (while
// applyCounterMutationOnLeader assumes it is on the MUTATION stage already)
public static AbstractWriteResponseHandler<IMutation> applyCounterMutationOnCoordinator(CounterMutation cm, String localDataCenter)
throws UnavailableException, OverloadedException
{
return performWrite(cm, cm.consistency(), localDataCenter, counterWriteOnCoordinatorPerformer, null, WriteType.COUNTER);
}
private static Runnable counterWriteTask(final IMutation mutation,
final Iterable<InetAddress> targets,
final AbstractWriteResponseHandler<IMutation> responseHandler,
final String localDataCenter)
{
return new DroppableRunnable(MessagingService.Verb.COUNTER_MUTATION)
{
@Override
public void runMayThrow() throws OverloadedException, WriteTimeoutException
{
assert mutation instanceof CounterMutation;
Mutation result = ((CounterMutation) mutation).apply();
responseHandler.response(null);
Set<InetAddress> remotes = Sets.difference(ImmutableSet.copyOf(targets),
ImmutableSet.of(FBUtilities.getBroadcastAddress()));
if (!remotes.isEmpty())
sendToHintedEndpoints(result, remotes, responseHandler, localDataCenter);
}
};
}
private static boolean systemKeyspaceQuery(List<ReadCommand> cmds)
{
for (ReadCommand cmd : cmds)
if (!cmd.ksName.equals(SystemKeyspace.NAME))
return false;
return true;
}
public static List<Row> read(List<ReadCommand> commands, ConsistencyLevel consistencyLevel)
throws UnavailableException, IsBootstrappingException, ReadFailureException, ReadTimeoutException, InvalidRequestException
{
// When using serial CL, the ClientState should be provided
assert !consistencyLevel.isSerialConsistency();
return read(commands, consistencyLevel, null);
}
/**
* Performs the actual reading of a row out of the StorageService, fetching
* a specific set of column names from a given column family.
*/
public static List<Row> read(List<ReadCommand> commands, ConsistencyLevel consistencyLevel, ClientState state)
throws UnavailableException, IsBootstrappingException, ReadFailureException, ReadTimeoutException, InvalidRequestException
{
if (StorageService.instance.isBootstrapMode() && !systemKeyspaceQuery(commands))
{
readMetrics.unavailables.mark();
throw new IsBootstrappingException();
}
return consistencyLevel.isSerialConsistency()
? readWithPaxos(commands, consistencyLevel, state)
: readRegular(commands, consistencyLevel);
}
private static List<Row> readWithPaxos(List<ReadCommand> commands, ConsistencyLevel consistencyLevel, ClientState state)
throws InvalidRequestException, UnavailableException, ReadFailureException, ReadTimeoutException
{
assert state != null;
long start = System.nanoTime();
List<Row> rows = null;
try
{
// make sure any in-progress paxos writes are done (i.e., committed to a majority of replicas), before performing a quorum read
if (commands.size() > 1)
throw new InvalidRequestException("SERIAL/LOCAL_SERIAL consistency may only be requested for one row at a time");
ReadCommand command = commands.get(0);
CFMetaData metadata = Schema.instance.getCFMetaData(command.ksName, command.cfName);
Pair<List<InetAddress>, Integer> p = getPaxosParticipants(command.ksName, command.key, consistencyLevel);
List<InetAddress> liveEndpoints = p.left;
int requiredParticipants = p.right;
// does the work of applying in-progress writes; throws UAE or timeout if it can't
final ConsistencyLevel consistencyForCommitOrFetch = consistencyLevel == ConsistencyLevel.LOCAL_SERIAL
? ConsistencyLevel.LOCAL_QUORUM
: ConsistencyLevel.QUORUM;
try
{
final Pair<UUID, Integer> pair = beginAndRepairPaxos(start, command.key, metadata, liveEndpoints, requiredParticipants, consistencyLevel, consistencyForCommitOrFetch, false, state);
if (pair.right > 0)
casReadMetrics.contention.update(pair.right);
}
catch (WriteTimeoutException e)
{
throw new ReadTimeoutException(consistencyLevel, 0, consistencyLevel.blockFor(Keyspace.open(command.ksName)), false);
}
catch (WriteFailureException e)
{
throw new ReadFailureException(consistencyLevel, e.received, e.failures, e.blockFor, false);
}
rows = fetchRows(commands, consistencyForCommitOrFetch);
}
catch (UnavailableException e)
{
readMetrics.unavailables.mark();
casReadMetrics.unavailables.mark();
throw e;
}
catch (ReadTimeoutException e)
{
readMetrics.timeouts.mark();
casReadMetrics.timeouts.mark();
throw e;
}
catch (ReadFailureException e)
{
readMetrics.failures.mark();
casReadMetrics.failures.mark();
throw e;
}
finally
{
long latency = System.nanoTime() - start;
readMetrics.addNano(latency);
casReadMetrics.addNano(latency);
// TODO avoid giving every command the same latency number. Can fix this in CASSADRA-5329
for (ReadCommand command : commands)
Keyspace.open(command.ksName).getColumnFamilyStore(command.cfName).metric.coordinatorReadLatency.update(latency, TimeUnit.NANOSECONDS);
}
return rows;
}
private static List<Row> readRegular(List<ReadCommand> commands, ConsistencyLevel consistencyLevel)
throws UnavailableException, ReadFailureException, ReadTimeoutException
{
long start = System.nanoTime();
List<Row> rows = null;
try
{
rows = fetchRows(commands, consistencyLevel);
}
catch (UnavailableException e)
{
readMetrics.unavailables.mark();
throw e;
}
catch (ReadTimeoutException e)
{
readMetrics.timeouts.mark();
throw e;
}
catch (ReadFailureException e)
{
readMetrics.failures.mark();
throw e;
}
finally
{
long latency = System.nanoTime() - start;
readMetrics.addNano(latency);
// TODO avoid giving every command the same latency number. Can fix this in CASSADRA-5329
for (ReadCommand command : commands)
Keyspace.open(command.ksName).getColumnFamilyStore(command.cfName).metric.coordinatorReadLatency.update(latency, TimeUnit.NANOSECONDS);
}
return rows;
}
/**
* This function executes local and remote reads, and blocks for the results:
*
* 1. Get the replica locations, sorted by response time according to the snitch
* 2. Send a data request to the closest replica, and digest requests to either
* a) all the replicas, if read repair is enabled
* b) the closest R-1 replicas, where R is the number required to satisfy the ConsistencyLevel
* 3. Wait for a response from R replicas
* 4. If the digests (if any) match the data return the data
* 5. else carry out read repair by getting data from all the nodes.
*/
private static List<Row> fetchRows(List<ReadCommand> initialCommands, ConsistencyLevel consistencyLevel)
throws UnavailableException, ReadFailureException, ReadTimeoutException
{
List<Row> rows = new ArrayList<>(initialCommands.size());
// (avoid allocating a new list in the common case of nothing-to-retry)
List<ReadCommand> commandsToRetry = Collections.emptyList();
do
{
List<ReadCommand> commands = commandsToRetry.isEmpty() ? initialCommands : commandsToRetry;
AbstractReadExecutor[] readExecutors = new AbstractReadExecutor[commands.size()];
if (!commandsToRetry.isEmpty())
Tracing.trace("Retrying {} commands", commandsToRetry.size());
// send out read requests
for (int i = 0; i < commands.size(); i++)
{
ReadCommand command = commands.get(i);
assert !command.isDigestQuery();
AbstractReadExecutor exec = AbstractReadExecutor.getReadExecutor(command, consistencyLevel);
exec.executeAsync();
readExecutors[i] = exec;
}
for (AbstractReadExecutor exec : readExecutors)
exec.maybeTryAdditionalReplicas();
// read results and make a second pass for any digest mismatches
List<ReadCommand> repairCommands = null;
List<ReadCallback<ReadResponse, Row>> repairResponseHandlers = null;
for (AbstractReadExecutor exec: readExecutors)
{
try
{
Row row = exec.get();
if (row != null)
{
row = exec.command.maybeTrim(row);
rows.add(row);
}
if (logger.isTraceEnabled())
logger.trace("Read: {} ms.", TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - exec.handler.start));
}
catch (ReadTimeoutException|ReadFailureException ex)
{
int blockFor = consistencyLevel.blockFor(Keyspace.open(exec.command.getKeyspace()));
int responseCount = exec.handler.getReceivedCount();
String gotData = responseCount > 0
? exec.resolver.isDataPresent() ? " (including data)" : " (only digests)"
: "";
boolean isTimeout = ex instanceof ReadTimeoutException;
if (Tracing.isTracing())
{
Tracing.trace("{}; received {} of {} responses{}",
isTimeout ? "Timed out" : "Failed", responseCount, blockFor, gotData);
}
else if (logger.isDebugEnabled())
{
logger.debug("Read {}; received {} of {} responses{}", (isTimeout ? "timeout" : "failure"), responseCount, blockFor, gotData);
}
throw ex;
}
catch (DigestMismatchException ex)
{
Tracing.trace("Digest mismatch: {}", ex);
ReadRepairMetrics.repairedBlocking.mark();
// Do a full data read to resolve the correct response (and repair node that need be)
RowDataResolver resolver = new RowDataResolver(exec.command.ksName, exec.command.key, exec.command.filter(), exec.command.timestamp, exec.handler.endpoints.size());
ReadCallback<ReadResponse, Row> repairHandler = new ReadCallback<>(resolver,
ConsistencyLevel.ALL,
exec.getContactedReplicas().size(),
exec.command,
Keyspace.open(exec.command.getKeyspace()),
exec.handler.endpoints);
if (repairCommands == null)
{
repairCommands = new ArrayList<>();
repairResponseHandlers = new ArrayList<>();
}
repairCommands.add(exec.command);
repairResponseHandlers.add(repairHandler);
MessageOut<ReadCommand> message = exec.command.createMessage();
for (InetAddress endpoint : exec.getContactedReplicas())
{
Tracing.trace("Enqueuing full data read to {}", endpoint);
MessagingService.instance().sendRRWithFailure(message, endpoint, repairHandler);
}
}
}
commandsToRetry.clear();
// read the results for the digest mismatch retries
if (repairResponseHandlers != null)
{
for (int i = 0; i < repairCommands.size(); i++)
{
ReadCommand command = repairCommands.get(i);
ReadCallback<ReadResponse, Row> handler = repairResponseHandlers.get(i);
Row row;
try
{
row = handler.get();
}
catch (DigestMismatchException e)
{
throw new AssertionError(e); // full data requested from each node here, no digests should be sent
}
catch (ReadTimeoutException e)
{
if (Tracing.isTracing())
Tracing.trace("Timed out waiting on digest mismatch repair requests");
else
logger.trace("Timed out waiting on digest mismatch repair requests");
// the caught exception here will have CL.ALL from the repair command,
// not whatever CL the initial command was at (CASSANDRA-7947)
int blockFor = consistencyLevel.blockFor(Keyspace.open(command.getKeyspace()));
throw new ReadTimeoutException(consistencyLevel, blockFor-1, blockFor, true);
}
RowDataResolver resolver = (RowDataResolver)handler.resolver;
try
{
// wait for the repair writes to be acknowledged, to minimize impact on any replica that's
// behind on writes in case the out-of-sync row is read multiple times in quick succession
FBUtilities.waitOnFutures(resolver.repairResults, DatabaseDescriptor.getWriteRpcTimeout());
}
catch (TimeoutException e)
{
if (Tracing.isTracing())
Tracing.trace("Timed out waiting on digest mismatch repair acknowledgements");
else
logger.trace("Timed out waiting on digest mismatch repair acknowledgements");
int blockFor = consistencyLevel.blockFor(Keyspace.open(command.getKeyspace()));
throw new ReadTimeoutException(consistencyLevel, blockFor-1, blockFor, true);
}
// retry any potential short reads
ReadCommand retryCommand = command.maybeGenerateRetryCommand(resolver, row);
if (retryCommand != null)
{
Tracing.trace("Issuing retry for read command");
if (commandsToRetry == Collections.EMPTY_LIST)
commandsToRetry = new ArrayList<>();
commandsToRetry.add(retryCommand);
continue;
}
if (row != null)
{
row = command.maybeTrim(row);
rows.add(row);
}
}
}
} while (!commandsToRetry.isEmpty());
return rows;
}
static class LocalReadRunnable extends DroppableRunnable
{
private final ReadCommand command;
private final ReadCallback<ReadResponse, Row> handler;
private final long start = System.nanoTime();
LocalReadRunnable(ReadCommand command, ReadCallback<ReadResponse, Row> handler)
{
super(MessagingService.Verb.READ);
this.command = command;
this.handler = handler;
}
protected void runMayThrow()
{
try
{
Keyspace keyspace = Keyspace.open(command.ksName);
Row r = command.getRow(keyspace);
ReadResponse result = ReadVerbHandler.getResponse(command, r);
MessagingService.instance().addLatency(FBUtilities.getBroadcastAddress(), TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start));
handler.response(result);
}
catch (Throwable t)
{
handler.onFailure(FBUtilities.getBroadcastAddress());
if (t instanceof TombstoneOverwhelmingException)
logger.error(t.getMessage());
else
throw t;
}
}
}
static class LocalRangeSliceRunnable extends DroppableRunnable
{
private final AbstractRangeCommand command;
private final ReadCallback<RangeSliceReply, Iterable<Row>> handler;
private final long start = System.nanoTime();
LocalRangeSliceRunnable(AbstractRangeCommand command, ReadCallback<RangeSliceReply, Iterable<Row>> handler)
{
super(MessagingService.Verb.RANGE_SLICE);
this.command = command;
this.handler = handler;
}
protected void runMayThrow()
{
try
{
RangeSliceReply result = new RangeSliceReply(command.executeLocally());
MessagingService.instance().addLatency(FBUtilities.getBroadcastAddress(), TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start));
handler.response(result);
}
catch (Throwable t)
{
handler.onFailure(FBUtilities.getBroadcastAddress());
if (t instanceof TombstoneOverwhelmingException)
logger.error(t.getMessage());
else
throw t;
}
}
}
public static List<InetAddress> getLiveSortedEndpoints(Keyspace keyspace, ByteBuffer key)
{
return getLiveSortedEndpoints(keyspace, StorageService.getPartitioner().decorateKey(key));
}
private static List<InetAddress> getLiveSortedEndpoints(Keyspace keyspace, RingPosition pos)
{
List<InetAddress> liveEndpoints = StorageService.instance.getLiveNaturalEndpoints(keyspace, pos);
DatabaseDescriptor.getEndpointSnitch().sortByProximity(FBUtilities.getBroadcastAddress(), liveEndpoints);
return liveEndpoints;
}
private static List<InetAddress> intersection(List<InetAddress> l1, List<InetAddress> l2)
{
// Note: we don't use Guava Sets.intersection() for 3 reasons:
// 1) retainAll would be inefficient if l1 and l2 are large but in practice both are the replicas for a range and
// so will be very small (< RF). In that case, retainAll is in fact more efficient.
// 2) we do ultimately need a list so converting everything to sets don't make sense
// 3) l1 and l2 are sorted by proximity. The use of retainAll maintain that sorting in the result, while using sets wouldn't.
List<InetAddress> inter = new ArrayList<InetAddress>(l1);
inter.retainAll(l2);
return inter;
}
/**
* Estimate the number of result rows (either cql3 rows or storage rows, as called for by the command) per
* range in the ring based on our local data. This assumes that ranges are uniformly distributed across the cluster
* and that the queried data is also uniformly distributed.
*/
private static float estimateResultRowsPerRange(AbstractRangeCommand command, Keyspace keyspace)
{
ColumnFamilyStore cfs = keyspace.getColumnFamilyStore(command.columnFamily);
float resultRowsPerRange = Float.POSITIVE_INFINITY;
if (command.rowFilter != null && !command.rowFilter.isEmpty())
{
List<SecondaryIndexSearcher> searchers = cfs.indexManager.getIndexSearchersForQuery(command.rowFilter);
if (searchers.isEmpty())
{
resultRowsPerRange = calculateResultRowsUsingEstimatedKeys(cfs);
}
else
{
// Secondary index query (cql3 or otherwise). Estimate result rows based on most selective 2ary index.
for (SecondaryIndexSearcher searcher : searchers)
{
// use our own mean column count as our estimate for how many matching rows each node will have
SecondaryIndex highestSelectivityIndex = searcher.highestSelectivityIndex(command.rowFilter);
resultRowsPerRange = highestSelectivityIndex == null ? resultRowsPerRange : Math.min(resultRowsPerRange, highestSelectivityIndex.estimateResultRows());
}
}
}
else if (!command.countCQL3Rows())
{
// non-cql3 query
resultRowsPerRange = cfs.estimateKeys();
}
else
{
resultRowsPerRange = calculateResultRowsUsingEstimatedKeys(cfs);
}
// adjust resultRowsPerRange by the number of tokens this node has and the replication factor for this ks
return (resultRowsPerRange / DatabaseDescriptor.getNumTokens()) / keyspace.getReplicationStrategy().getReplicationFactor();
}
private static float calculateResultRowsUsingEstimatedKeys(ColumnFamilyStore cfs)
{
if (cfs.metadata.comparator.isDense())
{
// one storage row per result row, so use key estimate directly
return cfs.estimateKeys();
}
else
{
float resultRowsPerStorageRow = ((float) cfs.getMeanColumns()) / cfs.metadata.regularColumns().size();
return resultRowsPerStorageRow * (cfs.estimateKeys());
}
}
public static List<Row> getRangeSlice(AbstractRangeCommand command, ConsistencyLevel consistency_level)
throws UnavailableException, ReadFailureException, ReadTimeoutException
{
Tracing.trace("Computing ranges to query");
long startTime = System.nanoTime();
Keyspace keyspace = Keyspace.open(command.keyspace);
List<Row> rows;
// now scan until we have enough results
try
{
int liveRowCount = 0;
boolean countLiveRows = command.countCQL3Rows() || command.ignoredTombstonedPartitions();
rows = new ArrayList<>();
// when dealing with LocalStrategy keyspaces, we can skip the range splitting and merging (which can be
// expensive in clusters with vnodes)
List<? extends AbstractBounds<RowPosition>> ranges;
if (keyspace.getReplicationStrategy() instanceof LocalStrategy)
ranges = command.keyRange.unwrap();
else
ranges = getRestrictedRanges(command.keyRange);
// determine the number of rows to be fetched and the concurrency factor
int rowsToBeFetched = command.limit();
int concurrencyFactor;
if (command.requiresScanningAllRanges())
{
// all nodes must be queried
rowsToBeFetched *= ranges.size();
concurrencyFactor = ranges.size();
logger.debug("Requested rows: {}, ranges.size(): {}; concurrent range requests: {}",
command.limit(),
ranges.size(),
concurrencyFactor);
Tracing.trace("Submitting range requests on {} ranges with a concurrency of {}",
ranges.size(), concurrencyFactor);
}
else
{
// our estimate of how many result rows there will be per-range
float resultRowsPerRange = estimateResultRowsPerRange(command, keyspace);
// underestimate how many rows we will get per-range in order to increase the likelihood that we'll
// fetch enough rows in the first round
resultRowsPerRange -= resultRowsPerRange * CONCURRENT_SUBREQUESTS_MARGIN;
concurrencyFactor = resultRowsPerRange == 0.0
? 1
: Math.max(1, Math.min(ranges.size(), (int) Math.ceil(command.limit() / resultRowsPerRange)));
logger.trace("Estimated result rows per range: {}; requested rows: {}, ranges.size(): {}; concurrent range requests: {}",
resultRowsPerRange,
command.limit(),
ranges.size(),
concurrencyFactor);
Tracing.trace("Submitting range requests on {} ranges with a concurrency of {} ({} rows per range expected)",
ranges.size(),
concurrencyFactor,
resultRowsPerRange);
}
boolean haveSufficientRows = false;
int i = 0;
AbstractBounds<RowPosition> nextRange = null;
List<InetAddress> nextEndpoints = null;
List<InetAddress> nextFilteredEndpoints = null;
while (i < ranges.size())
{
List<Pair<AbstractRangeCommand, ReadCallback<RangeSliceReply, Iterable<Row>>>> scanHandlers = new ArrayList<>(concurrencyFactor);
int concurrentFetchStartingIndex = i;
int concurrentRequests = 0;
while ((i - concurrentFetchStartingIndex) < concurrencyFactor)
{
AbstractBounds<RowPosition> range = nextRange == null
? ranges.get(i)
: nextRange;
List<InetAddress> liveEndpoints = nextEndpoints == null
? getLiveSortedEndpoints(keyspace, range.right)
: nextEndpoints;
List<InetAddress> filteredEndpoints = nextFilteredEndpoints == null
? consistency_level.filterForQuery(keyspace, liveEndpoints)
: nextFilteredEndpoints;
++i;
++concurrentRequests;
// getRestrictedRange has broken the queried range into per-[vnode] token ranges, but this doesn't take
// the replication factor into account. If the intersection of live endpoints for 2 consecutive ranges
// still meets the CL requirements, then we can merge both ranges into the same RangeSliceCommand.
while (i < ranges.size())
{
nextRange = ranges.get(i);
nextEndpoints = getLiveSortedEndpoints(keyspace, nextRange.right);
nextFilteredEndpoints = consistency_level.filterForQuery(keyspace, nextEndpoints);
// If the current range right is the min token, we should stop merging because CFS.getRangeSlice
// don't know how to deal with a wrapping range.
// Note: it would be slightly more efficient to have CFS.getRangeSlice on the destination nodes unwraps
// the range if necessary and deal with it. However, we can't start sending wrapped range without breaking
// wire compatibility, so It's likely easier not to bother;
if (range.right.isMinimum())
break;
List<InetAddress> merged = intersection(liveEndpoints, nextEndpoints);
// Check if there is enough endpoint for the merge to be possible.
if (!consistency_level.isSufficientLiveNodes(keyspace, merged))
break;
List<InetAddress> filteredMerged = consistency_level.filterForQuery(keyspace, merged);
// Estimate whether merging will be a win or not
if (!DatabaseDescriptor.getEndpointSnitch().isWorthMergingForRangeQuery(filteredMerged, filteredEndpoints, nextFilteredEndpoints))
break;
// If we get there, merge this range and the next one
range = range.withNewRight(nextRange.right);
liveEndpoints = merged;
filteredEndpoints = filteredMerged;
++i;
}
AbstractRangeCommand nodeCmd = command.forSubRange(range);
// collect replies and resolve according to consistency level
RangeSliceResponseResolver resolver = new RangeSliceResponseResolver(nodeCmd.keyspace, command.timestamp);
List<InetAddress> minimalEndpoints = filteredEndpoints.subList(0, Math.min(filteredEndpoints.size(), consistency_level.blockFor(keyspace)));
ReadCallback<RangeSliceReply, Iterable<Row>> handler = new ReadCallback<>(resolver, consistency_level, nodeCmd, minimalEndpoints);
handler.assureSufficientLiveNodes();
resolver.setSources(filteredEndpoints);
if (filteredEndpoints.size() == 1
&& filteredEndpoints.get(0).equals(FBUtilities.getBroadcastAddress()))
{
StageManager.getStage(Stage.READ).execute(new LocalRangeSliceRunnable(nodeCmd, handler));
}
else
{
MessageOut<? extends AbstractRangeCommand> message = nodeCmd.createMessage();
for (InetAddress endpoint : filteredEndpoints)
{
Tracing.trace("Enqueuing request to {}", endpoint);
MessagingService.instance().sendRRWithFailure(message, endpoint, handler);
}
}
scanHandlers.add(Pair.create(nodeCmd, handler));
}
Tracing.trace("Submitted {} concurrent range requests covering {} ranges", concurrentRequests, i - concurrentFetchStartingIndex);
List<AsyncOneResponse> repairResponses = new ArrayList<>();
for (Pair<AbstractRangeCommand, ReadCallback<RangeSliceReply, Iterable<Row>>> cmdPairHandler : scanHandlers)
{
ReadCallback<RangeSliceReply, Iterable<Row>> handler = cmdPairHandler.right;
RangeSliceResponseResolver resolver = (RangeSliceResponseResolver)handler.resolver;
try
{
for (Row row : handler.get())
{
rows.add(row);
if (countLiveRows)
liveRowCount += row.getLiveCount(command.predicate, command.timestamp);
}
repairResponses.addAll(resolver.repairResults);
}
catch (ReadTimeoutException|ReadFailureException ex)
{
// we timed out or failed waiting for responses
int blockFor = consistency_level.blockFor(keyspace);
int responseCount = resolver.responses.size();
String gotData = responseCount > 0
? resolver.isDataPresent() ? " (including data)" : " (only digests)"
: "";
boolean isTimeout = ex instanceof ReadTimeoutException;
if (Tracing.isTracing())
{
Tracing.trace("{}; received {} of {} responses{} for range {} of {}",
(isTimeout ? "Timed out" : "Failed"), responseCount, blockFor, gotData, i, ranges.size());
}
else if (logger.isDebugEnabled())
{
logger.debug("Range slice {}; received {} of {} responses{} for range {} of {}",
(isTimeout ? "timeout" : "failure"), responseCount, blockFor, gotData, i, ranges.size());
}
throw ex;
}
catch (DigestMismatchException e)
{
throw new AssertionError(e); // no digests in range slices yet
}
// if we're done, great, otherwise, move to the next range
int count = countLiveRows ? liveRowCount : rows.size();
if (count >= rowsToBeFetched)
{
haveSufficientRows = true;
break;
}
}
try
{
FBUtilities.waitOnFutures(repairResponses, DatabaseDescriptor.getWriteRpcTimeout());
}
catch (TimeoutException ex)
{
// We got all responses, but timed out while repairing
int blockFor = consistency_level.blockFor(keyspace);
if (Tracing.isTracing())
Tracing.trace("Timed out while read-repairing after receiving all {} data and digest responses", blockFor);
else
logger.debug("Range slice timeout while read-repairing after receiving all {} data and digest responses", blockFor);
throw new ReadTimeoutException(consistency_level, blockFor-1, blockFor, true);
}
if (haveSufficientRows)
return command.postReconciliationProcessing(rows);
// we didn't get enough rows in our concurrent fetch; recalculate our concurrency factor
// based on the results we've seen so far (as long as we still have ranges left to query)
if (i < ranges.size())
{
float fetchedRows = countLiveRows ? liveRowCount : rows.size();
float remainingRows = rowsToBeFetched - fetchedRows;
float actualRowsPerRange;
if (fetchedRows == 0.0)
{
// we haven't actually gotten any results, so query all remaining ranges at once
actualRowsPerRange = 0.0f;
concurrencyFactor = ranges.size() - i;
}
else
{
actualRowsPerRange = fetchedRows / i;
concurrencyFactor = Math.max(1, Math.min(ranges.size() - i, Math.round(remainingRows / actualRowsPerRange)));
}
logger.trace("Didn't get enough response rows; actual rows per range: {}; remaining rows: {}, new concurrent requests: {}",
actualRowsPerRange, (int) remainingRows, concurrencyFactor);
}
}
}
finally
{
long latency = System.nanoTime() - startTime;
rangeMetrics.addNano(latency);
Keyspace.open(command.keyspace).getColumnFamilyStore(command.columnFamily).metric.coordinatorScanLatency.update(latency, TimeUnit.NANOSECONDS);
}
return command.postReconciliationProcessing(rows);
}
public Map<String, List<String>> getSchemaVersions()
{
return describeSchemaVersions();
}
/**
* initiate a request/response session with each live node to check whether or not everybody is using the same
* migration id. This is useful for determining if a schema change has propagated through the cluster. Disagreement
* is assumed if any node fails to respond.
*/
public static Map<String, List<String>> describeSchemaVersions()
{
final String myVersion = Schema.instance.getVersion().toString();
final Map<InetAddress, UUID> versions = new ConcurrentHashMap<InetAddress, UUID>();
final Set<InetAddress> liveHosts = Gossiper.instance.getLiveMembers();
final CountDownLatch latch = new CountDownLatch(liveHosts.size());
IAsyncCallback<UUID> cb = new IAsyncCallback<UUID>()
{
public void response(MessageIn<UUID> message)
{
// record the response from the remote node.
versions.put(message.from, message.payload);
latch.countDown();
}
public boolean isLatencyForSnitch()
{
return false;
}
};
// an empty message acts as a request to the SchemaCheckVerbHandler.
MessageOut message = new MessageOut(MessagingService.Verb.SCHEMA_CHECK);
for (InetAddress endpoint : liveHosts)
MessagingService.instance().sendRR(message, endpoint, cb);
try
{
// wait for as long as possible. timeout-1s if possible.
latch.await(DatabaseDescriptor.getRpcTimeout(), TimeUnit.MILLISECONDS);
}
catch (InterruptedException ex)
{
throw new AssertionError("This latch shouldn't have been interrupted.");
}
// maps versions to hosts that are on that version.
Map<String, List<String>> results = new HashMap<String, List<String>>();
Iterable<InetAddress> allHosts = Iterables.concat(Gossiper.instance.getLiveMembers(), Gossiper.instance.getUnreachableMembers());
for (InetAddress host : allHosts)
{
UUID version = versions.get(host);
String stringVersion = version == null ? UNREACHABLE : version.toString();
List<String> hosts = results.get(stringVersion);
if (hosts == null)
{
hosts = new ArrayList<String>();
results.put(stringVersion, hosts);
}
hosts.add(host.getHostAddress());
}
// we're done: the results map is ready to return to the client. the rest is just debug logging:
if (results.get(UNREACHABLE) != null)
logger.debug("Hosts not in agreement. Didn't get a response from everybody: {}", StringUtils.join(results.get(UNREACHABLE), ","));
for (Map.Entry<String, List<String>> entry : results.entrySet())
{
// check for version disagreement. log the hosts that don't agree.
if (entry.getKey().equals(UNREACHABLE) || entry.getKey().equals(myVersion))
continue;
for (String host : entry.getValue())
logger.debug("{} disagrees ({})", host, entry.getKey());
}
if (results.size() == 1)
logger.debug("Schemas are in agreement.");
return results;
}
/**
* Compute all ranges we're going to query, in sorted order. Nodes can be replica destinations for many ranges,
* so we need to restrict each scan to the specific range we want, or else we'd get duplicate results.
*/
static <T extends RingPosition<T>> List<AbstractBounds<T>> getRestrictedRanges(final AbstractBounds<T> queryRange)
{
// special case for bounds containing exactly 1 (non-minimum) token
if (queryRange instanceof Bounds && queryRange.left.equals(queryRange.right) && !queryRange.left.isMinimum())
{
return Collections.singletonList(queryRange);
}
TokenMetadata tokenMetadata = StorageService.instance.getTokenMetadata();
List<AbstractBounds<T>> ranges = new ArrayList<AbstractBounds<T>>();
// divide the queryRange into pieces delimited by the ring and minimum tokens
Iterator<Token> ringIter = TokenMetadata.ringIterator(tokenMetadata.sortedTokens(), queryRange.left.getToken(), true);
AbstractBounds<T> remainder = queryRange;
while (ringIter.hasNext())
{
/*
* remainder can be a range/bounds of token _or_ keys and we want to split it with a token:
* - if remainder is tokens, then we'll just split using the provided token.
* - if remainder is keys, we want to split using token.upperBoundKey. For instance, if remainder
* is [DK(10, 'foo'), DK(20, 'bar')], and we have 3 nodes with tokens 0, 15, 30. We want to
* split remainder to A=[DK(10, 'foo'), 15] and B=(15, DK(20, 'bar')]. But since we can't mix
* tokens and keys at the same time in a range, we uses 15.upperBoundKey() to have A include all
* keys having 15 as token and B include none of those (since that is what our node owns).
* asSplitValue() abstracts that choice.
*/
Token upperBoundToken = ringIter.next();
T upperBound = (T)upperBoundToken.upperBound(queryRange.left.getClass());
if (!remainder.left.equals(upperBound) && !remainder.contains(upperBound))
// no more splits
break;
Pair<AbstractBounds<T>,AbstractBounds<T>> splits = remainder.split(upperBound);
if (splits == null)
continue;
ranges.add(splits.left);
remainder = splits.right;
}
ranges.add(remainder);
return ranges;
}
public boolean getHintedHandoffEnabled()
{
return DatabaseDescriptor.hintedHandoffEnabled();
}
public Set<String> getHintedHandoffEnabledByDC()
{
return DatabaseDescriptor.hintedHandoffEnabledByDC();
}
public void setHintedHandoffEnabled(boolean b)
{
DatabaseDescriptor.setHintedHandoffEnabled(b);
}
public void setHintedHandoffEnabledByDCList(String dcNames)
{
DatabaseDescriptor.setHintedHandoffEnabled(dcNames);
}
public int getMaxHintWindow()
{
return DatabaseDescriptor.getMaxHintWindow();
}
public void setMaxHintWindow(int ms)
{
DatabaseDescriptor.setMaxHintWindow(ms);
}
public static boolean shouldHint(InetAddress ep)
{
if (DatabaseDescriptor.hintedHandoffEnabled())
{
if (DatabaseDescriptor.shouldHintByDC())
{
final String dc = DatabaseDescriptor.getEndpointSnitch().getDatacenter(ep);
// Disable DC specific hints
if (!DatabaseDescriptor.hintedHandoffEnabled(dc))
{
return false;
}
}
boolean hintWindowExpired = Gossiper.instance.getEndpointDowntime(ep) > DatabaseDescriptor.getMaxHintWindow();
if (hintWindowExpired)
{
HintedHandOffManager.instance.metrics.incrPastWindow(ep);
Tracing.trace("Not hinting {} which has been down {}ms", ep, Gossiper.instance.getEndpointDowntime(ep));
}
return !hintWindowExpired;
}
else
{
return false;
}
}
/**
* Performs the truncate operatoin, which effectively deletes all data from
* the column family cfname
* @param keyspace
* @param cfname
* @throws UnavailableException If some of the hosts in the ring are down.
* @throws TimeoutException
* @throws IOException
*/
public static void truncateBlocking(String keyspace, String cfname) throws UnavailableException, TimeoutException, IOException
{
logger.debug("Starting a blocking truncate operation on keyspace {}, CF {}", keyspace, cfname);
if (isAnyStorageHostDown())
{
logger.info("Cannot perform truncate, some hosts are down");
// Since the truncate operation is so aggressive and is typically only
// invoked by an admin, for simplicity we require that all nodes are up
// to perform the operation.
int liveMembers = Gossiper.instance.getLiveMembers().size();
throw new UnavailableException(ConsistencyLevel.ALL, liveMembers + Gossiper.instance.getUnreachableMembers().size(), liveMembers);
}
Set<InetAddress> allEndpoints = StorageService.instance.getLiveRingMembers(true);
int blockFor = allEndpoints.size();
final TruncateResponseHandler responseHandler = new TruncateResponseHandler(blockFor);
// Send out the truncate calls and track the responses with the callbacks.
Tracing.trace("Enqueuing truncate messages to hosts {}", allEndpoints);
final Truncation truncation = new Truncation(keyspace, cfname);
MessageOut<Truncation> message = truncation.createMessage();
for (InetAddress endpoint : allEndpoints)
MessagingService.instance().sendRR(message, endpoint, responseHandler);
// Wait for all
try
{
responseHandler.get();
}
catch (TimeoutException e)
{
Tracing.trace("Timed out");
throw e;
}
}
/**
* Asks the gossiper if there are any nodes that are currently down.
* @return true if the gossiper thinks all nodes are up.
*/
private static boolean isAnyStorageHostDown()
{
return !Gossiper.instance.getUnreachableTokenOwners().isEmpty();
}
public interface WritePerformer
{
public void apply(IMutation mutation,
Iterable<InetAddress> targets,
AbstractWriteResponseHandler<IMutation> responseHandler,
String localDataCenter,
ConsistencyLevel consistencyLevel) throws OverloadedException;
}
/**
* A Runnable that aborts if it doesn't start running before it times out
*/
private static abstract class DroppableRunnable implements Runnable
{
private final long constructionTime = System.nanoTime();
private final MessagingService.Verb verb;
public DroppableRunnable(MessagingService.Verb verb)
{
this.verb = verb;
}
public final void run()
{
if (TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - constructionTime) > DatabaseDescriptor.getTimeout(verb))
{
MessagingService.instance().incrementDroppedMessages(verb);
return;
}
try
{
runMayThrow();
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
abstract protected void runMayThrow() throws Exception;
}
/**
* Like DroppableRunnable, but if it aborts, it will rerun (on the mutation stage) after
* marking itself as a hint in progress so that the hint backpressure mechanism can function.
*/
private static abstract class LocalMutationRunnable implements Runnable
{
private final long constructionTime = System.currentTimeMillis();
public final void run()
{
final MessagingService.Verb verb = verb();
if (System.currentTimeMillis() > constructionTime + DatabaseDescriptor.getTimeout(verb))
{
if (MessagingService.DROPPABLE_VERBS.contains(verb()))
MessagingService.instance().incrementDroppedMessages(verb);
HintRunnable runnable = new HintRunnable(FBUtilities.getBroadcastAddress())
{
protected void runMayThrow() throws Exception
{
LocalMutationRunnable.this.runMayThrow();
}
};
submitHint(runnable);
return;
}
try
{
runMayThrow();
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
abstract protected MessagingService.Verb verb();
abstract protected void runMayThrow() throws Exception;
}
/**
* HintRunnable will decrease totalHintsInProgress and targetHints when finished.
* It is the caller's responsibility to increment them initially.
*/
private abstract static class HintRunnable implements Runnable
{
public final InetAddress target;
protected HintRunnable(InetAddress target)
{
this.target = target;
}
public void run()
{
try
{
runMayThrow();
}
catch (Exception e)
{
throw new RuntimeException(e);
}
finally
{
StorageMetrics.totalHintsInProgress.dec();
getHintsInProgressFor(target).decrementAndGet();
}
}
abstract protected void runMayThrow() throws Exception;
}
public long getTotalHints()
{
return StorageMetrics.totalHints.getCount();
}
public int getMaxHintsInProgress()
{
return maxHintsInProgress;
}
public void setMaxHintsInProgress(int qs)
{
maxHintsInProgress = qs;
}
public int getHintsInProgress()
{
return (int) StorageMetrics.totalHintsInProgress.getCount();
}
public void verifyNoHintsInProgress()
{
if (getHintsInProgress() > 0)
logger.warn("Some hints were not written before shutdown. This is not supposed to happen. You should (a) run repair, and (b) file a bug report");
}
public Long getRpcTimeout() { return DatabaseDescriptor.getRpcTimeout(); }
public void setRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setRpcTimeout(timeoutInMillis); }
public Long getReadRpcTimeout() { return DatabaseDescriptor.getReadRpcTimeout(); }
public void setReadRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setReadRpcTimeout(timeoutInMillis); }
public Long getWriteRpcTimeout() { return DatabaseDescriptor.getWriteRpcTimeout(); }
public void setWriteRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setWriteRpcTimeout(timeoutInMillis); }
public Long getCounterWriteRpcTimeout() { return DatabaseDescriptor.getCounterWriteRpcTimeout(); }
public void setCounterWriteRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setCounterWriteRpcTimeout(timeoutInMillis); }
public Long getCasContentionTimeout() { return DatabaseDescriptor.getCasContentionTimeout(); }
public void setCasContentionTimeout(Long timeoutInMillis) { DatabaseDescriptor.setCasContentionTimeout(timeoutInMillis); }
public Long getRangeRpcTimeout() { return DatabaseDescriptor.getRangeRpcTimeout(); }
public void setRangeRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setRangeRpcTimeout(timeoutInMillis); }
public Long getTruncateRpcTimeout() { return DatabaseDescriptor.getTruncateRpcTimeout(); }
public void setTruncateRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setTruncateRpcTimeout(timeoutInMillis); }
public Long getNativeTransportMaxConcurrentConnections() { return DatabaseDescriptor.getNativeTransportMaxConcurrentConnections(); }
public void setNativeTransportMaxConcurrentConnections(Long nativeTransportMaxConcurrentConnections) { DatabaseDescriptor.setNativeTransportMaxConcurrentConnections(nativeTransportMaxConcurrentConnections); }
public Long getNativeTransportMaxConcurrentConnectionsPerIp() { return DatabaseDescriptor.getNativeTransportMaxConcurrentConnectionsPerIp(); }
public void setNativeTransportMaxConcurrentConnectionsPerIp(Long nativeTransportMaxConcurrentConnections) { DatabaseDescriptor.setNativeTransportMaxConcurrentConnectionsPerIp(nativeTransportMaxConcurrentConnections); }
public void reloadTriggerClasses() { TriggerExecutor.instance.reloadClasses(); }
public long getReadRepairAttempted() {
return ReadRepairMetrics.attempted.getCount();
}
public long getReadRepairRepairedBlocking() {
return ReadRepairMetrics.repairedBlocking.getCount();
}
public long getReadRepairRepairedBackground() {
return ReadRepairMetrics.repairedBackground.getCount();
}
}