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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.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.function.Supplier;
import com.google.common.base.Preconditions;
import com.google.common.cache.CacheLoader;
import com.google.common.collect.Iterables;
import com.google.common.primitives.Ints;
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.batchlog.Batch;
import org.apache.cassandra.batchlog.BatchlogManager;
import org.apache.cassandra.concurrent.Stage;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.db.ConsistencyLevel;
import org.apache.cassandra.db.CounterMutation;
import org.apache.cassandra.db.DecoratedKey;
import org.apache.cassandra.db.IMutation;
import org.apache.cassandra.db.Keyspace;
import org.apache.cassandra.db.Mutation;
import org.apache.cassandra.db.PartitionRangeReadCommand;
import org.apache.cassandra.db.ReadCommand;
import org.apache.cassandra.db.ReadExecutionController;
import org.apache.cassandra.db.ReadResponse;
import org.apache.cassandra.db.SinglePartitionReadCommand;
import org.apache.cassandra.db.TruncateRequest;
import org.apache.cassandra.db.WriteType;
import org.apache.cassandra.db.filter.TombstoneOverwhelmingException;
import org.apache.cassandra.db.partitions.FilteredPartition;
import org.apache.cassandra.db.partitions.PartitionIterator;
import org.apache.cassandra.db.partitions.PartitionIterators;
import org.apache.cassandra.db.partitions.PartitionUpdate;
import org.apache.cassandra.db.partitions.UnfilteredPartitionIterator;
import org.apache.cassandra.db.rows.RowIterator;
import org.apache.cassandra.db.view.ViewUtils;
import org.apache.cassandra.dht.Token;
import org.apache.cassandra.exceptions.CasWriteTimeoutException;
import org.apache.cassandra.exceptions.CasWriteUnknownResultException;
import org.apache.cassandra.exceptions.InvalidRequestException;
import org.apache.cassandra.exceptions.IsBootstrappingException;
import org.apache.cassandra.exceptions.OverloadedException;
import org.apache.cassandra.exceptions.ReadFailureException;
import org.apache.cassandra.exceptions.ReadTimeoutException;
import org.apache.cassandra.exceptions.RequestFailureException;
import org.apache.cassandra.exceptions.RequestFailureReason;
import org.apache.cassandra.exceptions.RequestTimeoutException;
import org.apache.cassandra.exceptions.UnavailableException;
import org.apache.cassandra.exceptions.WriteFailureException;
import org.apache.cassandra.exceptions.WriteTimeoutException;
import org.apache.cassandra.gms.FailureDetector;
import org.apache.cassandra.gms.Gossiper;
import org.apache.cassandra.hints.Hint;
import org.apache.cassandra.hints.HintsService;
import org.apache.cassandra.locator.AbstractReplicationStrategy;
import org.apache.cassandra.locator.EndpointsForToken;
import org.apache.cassandra.locator.IEndpointSnitch;
import org.apache.cassandra.locator.InetAddressAndPort;
import org.apache.cassandra.locator.Replica;
import org.apache.cassandra.locator.ReplicaLayout;
import org.apache.cassandra.locator.ReplicaPlan;
import org.apache.cassandra.locator.ReplicaPlans;
import org.apache.cassandra.locator.Replicas;
import org.apache.cassandra.metrics.CASClientRequestMetrics;
import org.apache.cassandra.metrics.ReadRepairMetrics;
import org.apache.cassandra.metrics.StorageMetrics;
import org.apache.cassandra.net.ForwardingInfo;
import org.apache.cassandra.net.Message;
import org.apache.cassandra.net.MessageFlag;
import org.apache.cassandra.net.MessagingService;
import org.apache.cassandra.net.RequestCallback;
import org.apache.cassandra.net.Verb;
import org.apache.cassandra.schema.Schema;
import org.apache.cassandra.schema.SchemaConstants;
import org.apache.cassandra.schema.TableMetadata;
import org.apache.cassandra.service.paxos.Commit;
import org.apache.cassandra.service.paxos.PaxosState;
import org.apache.cassandra.service.paxos.PrepareCallback;
import org.apache.cassandra.service.paxos.ProposeCallback;
import org.apache.cassandra.service.reads.AbstractReadExecutor;
import org.apache.cassandra.service.reads.ReadCallback;
import org.apache.cassandra.service.reads.range.RangeCommands;
import org.apache.cassandra.service.reads.repair.ReadRepair;
import org.apache.cassandra.tracing.Tracing;
import org.apache.cassandra.triggers.TriggerExecutor;
import org.apache.cassandra.utils.FBUtilities;
import org.apache.cassandra.utils.MBeanWrapper;
import org.apache.cassandra.utils.MonotonicClock;
import org.apache.cassandra.utils.Pair;
import org.apache.cassandra.utils.UUIDGen;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
import static org.apache.cassandra.metrics.ClientRequestsMetricsHolder.casReadMetrics;
import static org.apache.cassandra.metrics.ClientRequestsMetricsHolder.casWriteMetrics;
import static org.apache.cassandra.metrics.ClientRequestsMetricsHolder.readMetrics;
import static org.apache.cassandra.metrics.ClientRequestsMetricsHolder.readMetricsForLevel;
import static org.apache.cassandra.metrics.ClientRequestsMetricsHolder.viewWriteMetrics;
import static org.apache.cassandra.metrics.ClientRequestsMetricsHolder.writeMetrics;
import static org.apache.cassandra.metrics.ClientRequestsMetricsHolder.writeMetricsForLevel;
import static org.apache.cassandra.net.NoPayload.noPayload;
import static org.apache.cassandra.net.Verb.BATCH_STORE_REQ;
import static org.apache.cassandra.net.Verb.MUTATION_REQ;
import static org.apache.cassandra.net.Verb.PAXOS_COMMIT_REQ;
import static org.apache.cassandra.net.Verb.PAXOS_PREPARE_REQ;
import static org.apache.cassandra.net.Verb.PAXOS_PROPOSE_REQ;
import static org.apache.cassandra.net.Verb.TRUNCATE_REQ;
import static org.apache.cassandra.service.BatchlogResponseHandler.BatchlogCleanup;
import static org.apache.cassandra.service.paxos.PrepareVerbHandler.doPrepare;
import static org.apache.cassandra.service.paxos.ProposeVerbHandler.doPropose;
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 hintsInProgress = new CacheLoader()
{
public AtomicInteger load(InetAddressAndPort inetAddress)
{
return new AtomicInteger(0);
}
};
private static final String DISABLE_SERIAL_READ_LINEARIZABILITY_KEY = "cassandra.unsafe.disable-serial-reads-linearizability";
private static final boolean disableSerialReadLinearizability =
Boolean.parseBoolean(System.getProperty(DISABLE_SERIAL_READ_LINEARIZABILITY_KEY, "false"));
private StorageProxy()
{
}
static
{
MBeanWrapper.instance.registerMBean(instance, MBEAN_NAME);
HintsService.instance.registerMBean();
standardWritePerformer = (mutation, targets, responseHandler, localDataCenter) ->
{
assert mutation instanceof Mutation;
sendToHintedReplicas((Mutation) mutation, targets, responseHandler, localDataCenter, Stage.MUTATION);
};
/*
* 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 = (mutation, targets, responseHandler, localDataCenter) ->
{
EndpointsForToken selected = targets.contacts().withoutSelf();
Replicas.temporaryAssertFull(selected); // TODO CASSANDRA-14548
counterWriteTask(mutation, targets.withContact(selected), responseHandler, localDataCenter).run();
};
counterWriteOnCoordinatorPerformer = (mutation, targets, responseHandler, localDataCenter) ->
{
EndpointsForToken selected = targets.contacts().withoutSelf();
Replicas.temporaryAssertFull(selected); // TODO CASSANDRA-14548
Stage.COUNTER_MUTATION.executor()
.execute(counterWriteTask(mutation, targets.withContact(selected), responseHandler, localDataCenter));
};
ReadRepairMetrics.init();
if (disableSerialReadLinearizability)
{
logger.warn("This node was started with -D{}. SERIAL (and LOCAL_SERIAL) reads coordinated by this node " +
"will not offer linearizability (see CASSANDRA-12126 for details on what this mean) with " +
"respect to other SERIAL operations. Please note that, with this flag, SERIAL reads will be " +
"slower than QUORUM reads, yet offer no more guarantee. This flag should only be used in " +
"the restricted case of upgrading from a pre-CASSANDRA-12126 version, and only if you " +
"understand the tradeoff.", DISABLE_SERIAL_READ_LINEARIZABILITY_KEY);
}
}
/**
* 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 respond, 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 RowIterator cas(String keyspaceName,
String cfName,
DecoratedKey key,
CASRequest request,
ConsistencyLevel consistencyForPaxos,
ConsistencyLevel consistencyForCommit,
ClientState state,
int nowInSeconds,
long queryStartNanoTime)
throws UnavailableException, IsBootstrappingException, RequestFailureException, RequestTimeoutException, InvalidRequestException, CasWriteUnknownResultException
{
final long startTimeForMetrics = System.nanoTime();
try
{
TableMetadata metadata = Schema.instance.validateTable(keyspaceName, cfName);
Supplier> updateProposer = () ->
{
// read the current values and check they validate the conditions
Tracing.trace("Reading existing values for CAS precondition");
SinglePartitionReadCommand readCommand = (SinglePartitionReadCommand) request.readCommand(nowInSeconds);
ConsistencyLevel readConsistency = consistencyForPaxos == ConsistencyLevel.LOCAL_SERIAL ? ConsistencyLevel.LOCAL_QUORUM : ConsistencyLevel.QUORUM;
FilteredPartition current;
try (RowIterator rowIter = readOne(readCommand, readConsistency, queryStartNanoTime))
{
current = FilteredPartition.create(rowIter);
}
if (!request.appliesTo(current))
{
Tracing.trace("CAS precondition does not match current values {}", current);
casWriteMetrics.conditionNotMet.inc();
return Pair.create(PartitionUpdate.emptyUpdate(metadata, key), current.rowIterator());
}
// Create the desired updates
PartitionUpdate updates = request.makeUpdates(current);
long size = updates.dataSize();
casWriteMetrics.mutationSize.update(size);
writeMetricsForLevel(consistencyForPaxos).mutationSize.update(size);
// 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(updates);
return Pair.create(updates, null);
};
return doPaxos(metadata,
key,
consistencyForPaxos,
consistencyForCommit,
consistencyForCommit,
state,
queryStartNanoTime,
casWriteMetrics,
updateProposer);
}
catch (CasWriteUnknownResultException e)
{
casWriteMetrics.unknownResult.mark();
throw e;
}
catch (CasWriteTimeoutException wte)
{
casWriteMetrics.timeouts.mark();
writeMetricsForLevel(consistencyForPaxos).timeouts.mark();
throw new CasWriteTimeoutException(wte.writeType, wte.consistency, wte.received, wte.blockFor, wte.contentions);
}
catch (ReadTimeoutException e)
{
casWriteMetrics.timeouts.mark();
writeMetricsForLevel(consistencyForPaxos).timeouts.mark();
throw e;
}
catch (WriteFailureException | ReadFailureException e)
{
casWriteMetrics.failures.mark();
writeMetricsForLevel(consistencyForPaxos).failures.mark();
throw e;
}
catch (UnavailableException e)
{
casWriteMetrics.unavailables.mark();
writeMetricsForLevel(consistencyForPaxos).unavailables.mark();
throw e;
}
finally
{
final long latency = System.nanoTime() - startTimeForMetrics;
casWriteMetrics.addNano(latency);
writeMetricsForLevel(consistencyForPaxos).addNano(latency);
}
}
private static void recordCasContention(TableMetadata table,
DecoratedKey key,
CASClientRequestMetrics casMetrics,
int contentions)
{
if (contentions == 0)
return;
casMetrics.contention.update(contentions);
Keyspace.open(table.keyspace)
.getColumnFamilyStore(table.name)
.metric
.topCasPartitionContention
.addSample(key.getKey(), contentions);
}
/**
* Performs the Paxos rounds for a given proposal, retrying when preempted until the timeout.
*
* The main 'configurable' of this method is the {@code createUpdateProposal} method: it is called by the method
* once a ballot has been successfully 'prepared' to generate the update to 'propose' (and commit if the proposal is
* successful). That method also generates the result that the whole method will return. Note that due to retrying,
* this method may be called multiple times and does not have to return the same results.
*
* @param metadata the table to update with Paxos.
* @param key the partition updated.
* @param consistencyForPaxos the serial consistency of the operation (either {@link ConsistencyLevel#SERIAL} or
* {@link ConsistencyLevel#LOCAL_SERIAL}).
* @param consistencyForReplayCommits the consistency for the commit phase of "replayed" in-progress operations.
* @param consistencyForCommit the consistency for the commit phase of _this_ operation update.
* @param state the client state.
* @param queryStartNanoTime the nano time for the start of the query this is part of. This is the base time for
* timeouts.
* @param casMetrics the metrics to update for this operation.
* @param createUpdateProposal method called after a successful 'prepare' phase to obtain 1) the actual update of
* this operation and 2) the result that the whole method should return. This can return {@code null} in the
* special where, after having "prepared" (and thus potentially replayed in-progress upgdates), we don't want
* to propose anything (the whole method then return {@code null}).
* @return the second element of the pair returned by {@code createUpdateProposal} (for the last call of that method
* if that method is called multiple times due to retries).
*/
private static RowIterator doPaxos(TableMetadata metadata,
DecoratedKey key,
ConsistencyLevel consistencyForPaxos,
ConsistencyLevel consistencyForReplayCommits,
ConsistencyLevel consistencyForCommit,
ClientState state,
long queryStartNanoTime,
CASClientRequestMetrics casMetrics,
Supplier> createUpdateProposal)
throws UnavailableException, IsBootstrappingException, RequestFailureException, RequestTimeoutException, InvalidRequestException
{
int contentions = 0;
Keyspace keyspace = Keyspace.open(metadata.keyspace);
AbstractReplicationStrategy latestRs = keyspace.getReplicationStrategy();
try
{
consistencyForPaxos.validateForCas();
consistencyForReplayCommits.validateForCasCommit(latestRs);
consistencyForCommit.validateForCasCommit(latestRs);
long timeoutNanos = DatabaseDescriptor.getCasContentionTimeout(NANOSECONDS);
while (System.nanoTime() - queryStartNanoTime < timeoutNanos)
{
// for simplicity, we'll do a single liveness check at the start of each attempt
ReplicaPlan.ForPaxosWrite replicaPlan = ReplicaPlans.forPaxos(keyspace, key, consistencyForPaxos);
latestRs = replicaPlan.replicationStrategy();
PaxosBallotAndContention pair = beginAndRepairPaxos(queryStartNanoTime,
key,
metadata,
replicaPlan,
consistencyForPaxos,
consistencyForReplayCommits,
casMetrics,
state);
final UUID ballot = pair.ballot;
contentions += pair.contentions;
Pair proposalPair = createUpdateProposal.get();
// See method javadoc: null here is code for "stop here and return null".
if (proposalPair == null)
return null;
Commit proposal = Commit.newProposal(ballot, proposalPair.left);
Tracing.trace("CAS precondition is met; proposing client-requested updates for {}", ballot);
if (proposePaxos(proposal, replicaPlan, true, queryStartNanoTime))
{
// We skip committing accepted updates when they are empty. This is an optimization which works
// because we also skip replaying those same empty update in beginAndRepairPaxos (see the longer
// comment there). As empty update are somewhat common (serial reads and non-applying CAS propose
// them), this is worth bothering.
if (!proposal.update.isEmpty())
commitPaxos(proposal, consistencyForCommit, true, queryStartNanoTime);
RowIterator result = proposalPair.right;
if (result != null)
Tracing.trace("CAS did not apply");
else
Tracing.trace("CAS applied successfully");
return result;
}
Tracing.trace("Paxos proposal not accepted (pre-empted by a higher ballot)");
contentions++;
Uninterruptibles.sleepUninterruptibly(ThreadLocalRandom.current().nextInt(100), TimeUnit.MILLISECONDS);
// continue to retry
}
}
catch (CasWriteTimeoutException e)
{
// Might be thrown by beginRepairAndPaxos. In that case, any contention that happened within the method and
// led up to the timeout was not accounted in our local 'contentions' variable and we add it now so it the
// contention recorded in the finally is correct.
contentions += e.contentions;
throw e;
}
catch (WriteTimeoutException e)
{
// Might be thrown by proposePaxos or commitPaxos
throw new CasWriteTimeoutException(e.writeType, e.consistency, e.received, e.blockFor, contentions);
}
finally
{
recordCasContention(metadata, key, casMetrics, contentions);
}
throw new CasWriteTimeoutException(WriteType.CAS, consistencyForPaxos, 0, consistencyForPaxos.blockFor(latestRs), contentions);
}
/**
* 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 PaxosBallotAndContention beginAndRepairPaxos(long queryStartNanoTime,
DecoratedKey key,
TableMetadata metadata,
ReplicaPlan.ForPaxosWrite paxosPlan,
ConsistencyLevel consistencyForPaxos,
ConsistencyLevel consistencyForCommit,
CASClientRequestMetrics casMetrics,
ClientState state)
throws WriteTimeoutException, WriteFailureException
{
long timeoutNanos = DatabaseDescriptor.getCasContentionTimeout(NANOSECONDS);
PrepareCallback summary = null;
int contentions = 0;
while (System.nanoTime() - queryStartNanoTime < timeoutNanos)
{
// 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.getTimestampForPaxos(minTimestampMicrosToUse);
// Note that ballotMicros is not guaranteed to be unique if two proposal are being handled concurrently by the same coordinator. But we still
// need ballots to be unique for each proposal so we have to use getRandomTimeUUIDFromMicros.
UUID ballot = UUIDGen.getRandomTimeUUIDFromMicros(ballotMicros);
// prepare
try
{
Tracing.trace("Preparing {}", ballot);
Commit toPrepare = Commit.newPrepare(key, metadata, ballot);
summary = preparePaxos(toPrepare, paxosPlan, queryStartNanoTime);
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), MILLISECONDS);
continue;
}
Commit inProgress = summary.mostRecentInProgressCommit;
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.
// One special case we make is for update that are empty (which are proposed by serial reads and
// non-applying CAS). While we could handle those as any other updates, we can optimize this somewhat by
// neither committing those empty updates, nor replaying in-progress ones. The reasoning is this: as the
// update is empty, we have nothing to apply to storage in the commit phase, so the only reason to commit
// would be to update the MRC. However, if we skip replaying those empty updates, then we don't need to
// update the MRC for following updates to make progress (that is, if we didn't had the empty update skip
// below _but_ skipped updating the MRC on empty updates, then we'd be stuck always proposing that same
// empty update). And the reason skipping that replay is safe is that when an operation tries to propose
// an empty value, there can be only 2 cases:
// 1) the propose succeed, meaning a quorum of nodes accept it, in which case we are guaranteed no earlier
// pending operation can ever be replayed (which is what we want to guarantee with the empty update).
// 2) the propose does not succeed. But then the operation proposing the empty update will not succeed
// either (it will retry or ultimately timeout), and we're actually ok if earlier pending operation gets
// replayed in that case.
// Tl;dr, it is safe to skip committing empty updates _as long as_ we also skip replying them below. And
// doing is more efficient, so we do so.
if (!inProgress.update.isEmpty() && inProgress.isAfter(mostRecent))
{
Tracing.trace("Finishing incomplete paxos round {}", inProgress);
casMetrics.unfinishedCommit.inc();
Commit refreshedInProgress = Commit.newProposal(ballot, inProgress.update);
if (proposePaxos(refreshedInProgress, paxosPlan, false, queryStartNanoTime))
{
commitPaxos(refreshedInProgress, consistencyForCommit, false, queryStartNanoTime);
}
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), 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.
int nowInSec = Ints.checkedCast(TimeUnit.MICROSECONDS.toSeconds(ballotMicros));
Iterable missingMRC = summary.replicasMissingMostRecentCommit(metadata, nowInSec);
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 new PaxosBallotAndContention(ballot, contentions);
}
catch (WriteTimeoutException e)
{
// We're still doing preparation for the paxos rounds, so we want to use the CAS (see CASSANDRA-8672)
throw new CasWriteTimeoutException(WriteType.CAS, e.consistency, e.received, e.blockFor, contentions);
}
}
throw new CasWriteTimeoutException(WriteType.CAS, consistencyForPaxos, 0, consistencyForPaxos.blockFor(paxosPlan.replicationStrategy()), contentions);
}
/**
* Unlike commitPaxos, this does not wait for replies
*/
private static void sendCommit(Commit commit, Iterable replicas)
{
Message message = Message.out(PAXOS_COMMIT_REQ, commit);
for (InetAddressAndPort target : replicas)
MessagingService.instance().send(message, target);
}
private static PrepareCallback preparePaxos(Commit toPrepare, ReplicaPlan.ForPaxosWrite replicaPlan, long queryStartNanoTime)
throws WriteTimeoutException
{
PrepareCallback callback = new PrepareCallback(toPrepare.update.partitionKey(), toPrepare.update.metadata(), replicaPlan.requiredParticipants(), replicaPlan.consistencyLevel(), queryStartNanoTime);
Message message = Message.out(PAXOS_PREPARE_REQ, toPrepare);
for (Replica replica: replicaPlan.contacts())
{
if (replica.isSelf())
{
PAXOS_PREPARE_REQ.stage.execute(() -> {
try
{
callback.onResponse(message.responseWith(doPrepare(toPrepare)));
}
catch (Exception ex)
{
logger.error("Failed paxos prepare locally", ex);
}
});
}
else
{
MessagingService.instance().sendWithCallback(message, replica.endpoint(), callback);
}
}
callback.await();
return callback;
}
/**
* Propose the {@param proposal} accoding to the {@param replicaPlan}.
* When {@param backoffIfPartial} is true, the proposer backs off when seeing the proposal being accepted by some but not a quorum.
* The result of the cooresponding CAS in uncertain as the accepted proposal may or may not be spread to other nodes in later rounds.
*/
private static boolean proposePaxos(Commit proposal, ReplicaPlan.ForPaxosWrite replicaPlan, boolean backoffIfPartial, long queryStartNanoTime)
throws WriteTimeoutException, CasWriteUnknownResultException
{
ProposeCallback callback = new ProposeCallback(replicaPlan.contacts().size(), replicaPlan.requiredParticipants(), !backoffIfPartial, replicaPlan.consistencyLevel(), queryStartNanoTime);
Message message = Message.out(PAXOS_PROPOSE_REQ, proposal);
for (Replica replica : replicaPlan.contacts())
{
if (replica.isSelf())
{
PAXOS_PROPOSE_REQ.stage.execute(() -> {
try
{
Message response = message.responseWith(doPropose(proposal));
callback.onResponse(response);
}
catch (Exception ex)
{
logger.error("Failed paxos propose locally", ex);
}
});
}
else
{
MessagingService.instance().sendWithCallback(message, replica.endpoint(), callback);
}
}
callback.await();
if (callback.isSuccessful())
return true;
if (backoffIfPartial && !callback.isFullyRefused())
throw new CasWriteUnknownResultException(replicaPlan.consistencyLevel(), callback.getAcceptCount(), replicaPlan.requiredParticipants());
return false;
}
private static void commitPaxos(Commit proposal, ConsistencyLevel consistencyLevel, boolean allowHints, long queryStartNanoTime) throws WriteTimeoutException
{
boolean shouldBlock = consistencyLevel != ConsistencyLevel.ANY;
Keyspace keyspace = Keyspace.open(proposal.update.metadata().keyspace);
Token tk = proposal.update.partitionKey().getToken();
AbstractWriteResponseHandler responseHandler = null;
// NOTE: this ReplicaPlan is a lie, this usage of ReplicaPlan could do with being clarified - the selected() collection is essentially (I think) never used
ReplicaPlan.ForTokenWrite replicaPlan = ReplicaPlans.forWrite(keyspace, consistencyLevel, tk, ReplicaPlans.writeAll);
if (shouldBlock)
{
AbstractReplicationStrategy rs = replicaPlan.replicationStrategy();
responseHandler = rs.getWriteResponseHandler(replicaPlan, null, WriteType.SIMPLE, queryStartNanoTime);
}
Message message = Message.outWithFlag(PAXOS_COMMIT_REQ, proposal, MessageFlag.CALL_BACK_ON_FAILURE);
for (Replica replica : replicaPlan.liveAndDown())
{
InetAddressAndPort destination = replica.endpoint();
checkHintOverload(replica);
if (replicaPlan.isAlive(replica))
{
if (shouldBlock)
{
if (replica.isSelf())
commitPaxosLocal(replica, message, responseHandler);
else
MessagingService.instance().sendWriteWithCallback(message, replica, responseHandler, allowHints && shouldHint(replica));
}
else
{
MessagingService.instance().send(message, destination);
}
}
else
{
if (responseHandler != null)
{
responseHandler.expired();
}
if (allowHints && shouldHint(replica))
{
submitHint(proposal.makeMutation(), replica, 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(Replica localReplica, final Message message, final AbstractWriteResponseHandler responseHandler)
{
PAXOS_COMMIT_REQ.stage.maybeExecuteImmediately(new LocalMutationRunnable(localReplica)
{
public void runMayThrow()
{
try
{
PaxosState.commit(message.payload);
if (responseHandler != null)
responseHandler.onResponse(null);
}
catch (Exception ex)
{
if (!(ex instanceof WriteTimeoutException))
logger.error("Failed to apply paxos commit locally : ", ex);
responseHandler.onFailure(FBUtilities.getBroadcastAddressAndPort(), RequestFailureReason.forException(ex));
}
}
@Override
protected Verb verb()
{
return PAXOS_COMMIT_REQ;
}
});
}
/**
* 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 consistencyLevel the consistency level for the operation
* @param queryStartNanoTime the value of System.nanoTime() when the query started to be processed
*/
public static void mutate(List mutations, ConsistencyLevel consistencyLevel, long queryStartNanoTime)
throws UnavailableException, OverloadedException, WriteTimeoutException, WriteFailureException
{
Tracing.trace("Determining replicas for mutation");
final String localDataCenter = DatabaseDescriptor.getEndpointSnitch().getLocalDatacenter();
long startTime = System.nanoTime();
List> responseHandlers = new ArrayList<>(mutations.size());
WriteType plainWriteType = mutations.size() <= 1 ? WriteType.SIMPLE : WriteType.UNLOGGED_BATCH;
try
{
for (IMutation mutation : mutations)
{
if (mutation instanceof CounterMutation)
responseHandlers.add(mutateCounter((CounterMutation)mutation, localDataCenter, queryStartNanoTime));
else
responseHandlers.add(performWrite(mutation, consistencyLevel, localDataCenter, standardWritePerformer, null, plainWriteType, queryStartNanoTime));
}
// upgrade to full quorum any failed cheap quorums
for (int i = 0 ; i < mutations.size() ; ++i)
{
if (!(mutations.get(i) instanceof CounterMutation)) // at the moment, only non-counter writes support cheap quorums
responseHandlers.get(i).maybeTryAdditionalReplicas(mutations.get(i), standardWritePerformer, localDataCenter);
}
// wait for writes. throws TimeoutException if necessary
for (AbstractWriteResponseHandler responseHandler : responseHandlers)
responseHandler.get();
}
catch (WriteTimeoutException|WriteFailureException ex)
{
if (consistencyLevel == ConsistencyLevel.ANY)
{
hintMutations(mutations);
}
else
{
if (ex instanceof WriteFailureException)
{
writeMetrics.failures.mark();
writeMetricsForLevel(consistencyLevel).failures.mark();
WriteFailureException fe = (WriteFailureException)ex;
Tracing.trace("Write failure; received {} of {} required replies, failed {} requests",
fe.received, fe.blockFor, fe.failureReasonByEndpoint.size());
}
else
{
writeMetrics.timeouts.mark();
writeMetricsForLevel(consistencyLevel).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();
writeMetricsForLevel(consistencyLevel).unavailables.mark();
Tracing.trace("Unavailable");
throw e;
}
catch (OverloadedException e)
{
writeMetrics.unavailables.mark();
writeMetricsForLevel(consistencyLevel).unavailables.mark();
Tracing.trace("Overloaded");
throw e;
}
finally
{
long latency = System.nanoTime() - startTime;
writeMetrics.addNano(latency);
writeMetricsForLevel(consistencyLevel).addNano(latency);
updateCoordinatorWriteLatencyTableMetric(mutations, latency);
}
}
/**
* 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.
*
* Only used for CL.ANY
*
* @param mutations the mutations that require hints
*/
private static void hintMutations(Collection mutations)
{
for (IMutation mutation : mutations)
if (!(mutation instanceof CounterMutation))
hintMutation((Mutation) mutation);
Tracing.trace("Wrote hints to satisfy CL.ANY after no replicas acknowledged the write");
}
private static void hintMutation(Mutation mutation)
{
String keyspaceName = mutation.getKeyspaceName();
Token token = mutation.key().getToken();
// local writes can timeout, but cannot be dropped (see LocalMutationRunnable and CASSANDRA-6510),
// so there is no need to hint or retry.
EndpointsForToken replicasToHint = ReplicaLayout.forTokenWriteLiveAndDown(Keyspace.open(keyspaceName), token)
.all()
.filter(StorageProxy::shouldHint);
submitHint(mutation, replicasToHint, null);
}
public boolean appliesLocally(Mutation mutation)
{
String keyspaceName = mutation.getKeyspaceName();
Token token = mutation.key().getToken();
InetAddressAndPort local = FBUtilities.getBroadcastAddressAndPort();
return ReplicaLayout.forTokenWriteLiveAndDown(Keyspace.open(keyspaceName), token)
.all().endpoints().contains(local);
}
/**
* Use this method to have these Mutations applied
* across all replicas.
*
* @param mutations the mutations to be applied across the replicas
* @param writeCommitLog if commitlog should be written
* @param baseComplete time from epoch in ms that the local base mutation was(or will be) completed
* @param queryStartNanoTime the value of System.nanoTime() when the query started to be processed
*/
public static void mutateMV(ByteBuffer dataKey, Collection mutations, boolean writeCommitLog, AtomicLong baseComplete, long queryStartNanoTime)
throws UnavailableException, OverloadedException, WriteTimeoutException
{
Tracing.trace("Determining replicas for mutation");
final String localDataCenter = DatabaseDescriptor.getEndpointSnitch().getLocalDatacenter();
long startTime = System.nanoTime();
try
{
// if we haven't joined the ring, write everything to batchlog because paired replicas may be stale
final UUID batchUUID = UUIDGen.getTimeUUID();
if (StorageService.instance.isStarting() || StorageService.instance.isJoining() || StorageService.instance.isMoving())
{
BatchlogManager.store(Batch.createLocal(batchUUID, FBUtilities.timestampMicros(),
mutations), writeCommitLog);
}
else
{
List wrappers = new ArrayList<>(mutations.size());
//non-local mutations rely on the base mutation commit-log entry for eventual consistency
Set nonLocalMutations = new HashSet<>(mutations);
Token baseToken = StorageService.instance.getTokenMetadata().partitioner.getToken(dataKey);
ConsistencyLevel consistencyLevel = ConsistencyLevel.ONE;
//Since the base -> view replication is 1:1 we only need to store the BL locally
ReplicaPlan.ForTokenWrite replicaPlan = ReplicaPlans.forLocalBatchlogWrite();
BatchlogCleanup cleanup = new BatchlogCleanup(mutations.size(),
() -> asyncRemoveFromBatchlog(replicaPlan, batchUUID));
// add a handler for each mutation - includes checking availability, but doesn't initiate any writes, yet
for (Mutation mutation : mutations)
{
String keyspaceName = mutation.getKeyspaceName();
Token tk = mutation.key().getToken();
AbstractReplicationStrategy replicationStrategy = Keyspace.open(keyspaceName).getReplicationStrategy();
Optional pairedEndpoint = ViewUtils.getViewNaturalEndpoint(replicationStrategy, baseToken, tk);
EndpointsForToken pendingReplicas = StorageService.instance.getTokenMetadata().pendingEndpointsForToken(tk, keyspaceName);
// if there are no paired endpoints there are probably range movements going on, so we write to the local batchlog to replay later
if (!pairedEndpoint.isPresent())
{
if (pendingReplicas.isEmpty())
logger.warn("Received base materialized view mutation for key {} that does not belong " +
"to this node. There is probably a range movement happening (move or decommission)," +
"but this node hasn't updated its ring metadata yet. Adding mutation to " +
"local batchlog to be replayed later.",
mutation.key());
continue;
}
// When local node is the endpoint we can just apply the mutation locally,
// unless there are pending endpoints, in which case we want to do an ordinary
// write so the view mutation is sent to the pending endpoint
if (pairedEndpoint.get().isSelf() && StorageService.instance.isJoined()
&& pendingReplicas.isEmpty())
{
try
{
mutation.apply(writeCommitLog);
nonLocalMutations.remove(mutation);
// won't trigger cleanup
cleanup.decrement();
}
catch (Exception exc)
{
logger.error("Error applying local view update: Mutation (keyspace {}, tables {}, partition key {})",
mutation.getKeyspaceName(), mutation.getTableIds(), mutation.key());
throw exc;
}
}
else
{
ReplicaLayout.ForTokenWrite liveAndDown = ReplicaLayout.forTokenWrite(replicationStrategy,
EndpointsForToken.of(tk, pairedEndpoint.get()),
pendingReplicas);
wrappers.add(wrapViewBatchResponseHandler(mutation,
consistencyLevel,
consistencyLevel,
liveAndDown,
baseComplete,
WriteType.BATCH,
cleanup,
queryStartNanoTime));
}
}
// Apply to local batchlog memtable in this thread
if (!nonLocalMutations.isEmpty())
BatchlogManager.store(Batch.createLocal(batchUUID, FBUtilities.timestampMicros(), nonLocalMutations), writeCommitLog);
// Perform remote writes
if (!wrappers.isEmpty())
asyncWriteBatchedMutations(wrappers, localDataCenter, Stage.VIEW_MUTATION);
}
}
finally
{
viewWriteMetrics.addNano(System.nanoTime() - startTime);
}
}
@SuppressWarnings("unchecked")
public static void mutateWithTriggers(List mutations,
ConsistencyLevel consistencyLevel,
boolean mutateAtomically,
long queryStartNanoTime)
throws WriteTimeoutException, WriteFailureException, UnavailableException, OverloadedException, InvalidRequestException
{
Collection augmented = TriggerExecutor.instance.execute(mutations);
boolean updatesView = Keyspace.open(mutations.iterator().next().getKeyspaceName())
.viewManager
.updatesAffectView(mutations, true);
long size = IMutation.dataSize(mutations);
writeMetrics.mutationSize.update(size);
writeMetricsForLevel(consistencyLevel).mutationSize.update(size);
if (augmented != null)
mutateAtomically(augmented, consistencyLevel, updatesView, queryStartNanoTime);
else
{
if (mutateAtomically || updatesView)
mutateAtomically((Collection) mutations, consistencyLevel, updatesView, queryStartNanoTime);
else
mutate(mutations, consistencyLevel, queryStartNanoTime);
}
}
/**
* 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
* @param requireQuorumForRemove at least a quorum of nodes will see update before deleting batchlog
* @param queryStartNanoTime the value of System.nanoTime() when the query started to be processed
*/
public static void mutateAtomically(Collection mutations,
ConsistencyLevel consistency_level,
boolean requireQuorumForRemove,
long queryStartNanoTime)
throws UnavailableException, OverloadedException, WriteTimeoutException
{
Tracing.trace("Determining replicas for atomic batch");
long startTime = System.nanoTime();
List wrappers = new ArrayList<>(mutations.size());
if (mutations.stream().anyMatch(mutation -> Keyspace.open(mutation.getKeyspaceName()).getReplicationStrategy().hasTransientReplicas()))
throw new AssertionError("Logged batches are unsupported with transient replication");
try
{
// If we are requiring quorum nodes for removal, we upgrade consistency level to QUORUM unless we already
// require ALL, or EACH_QUORUM. This is so that *at least* QUORUM nodes see the update.
ConsistencyLevel batchConsistencyLevel = requireQuorumForRemove
? ConsistencyLevel.QUORUM
: consistency_level;
switch (consistency_level)
{
case ALL:
case EACH_QUORUM:
batchConsistencyLevel = consistency_level;
}
ReplicaPlan.ForTokenWrite replicaPlan = ReplicaPlans.forBatchlogWrite(batchConsistencyLevel == ConsistencyLevel.ANY);
final UUID batchUUID = UUIDGen.getTimeUUID();
BatchlogCleanup cleanup = new BatchlogCleanup(mutations.size(),
() -> asyncRemoveFromBatchlog(replicaPlan, batchUUID));
// add a handler for each mutation - includes checking availability, but doesn't initiate any writes, yet
for (Mutation mutation : mutations)
{
WriteResponseHandlerWrapper wrapper = wrapBatchResponseHandler(mutation,
consistency_level,
batchConsistencyLevel,
WriteType.BATCH,
cleanup,
queryStartNanoTime);
// exit early if we can't fulfill the CL at this time.
wrappers.add(wrapper);
}
// write to the batchlog
syncWriteToBatchlog(mutations, replicaPlan, batchUUID, queryStartNanoTime);
// now actually perform the writes and wait for them to complete
syncWriteBatchedMutations(wrappers, Stage.MUTATION);
}
catch (UnavailableException e)
{
writeMetrics.unavailables.mark();
writeMetricsForLevel(consistency_level).unavailables.mark();
Tracing.trace("Unavailable");
throw e;
}
catch (WriteTimeoutException e)
{
writeMetrics.timeouts.mark();
writeMetricsForLevel(consistency_level).timeouts.mark();
Tracing.trace("Write timeout; received {} of {} required replies", e.received, e.blockFor);
throw e;
}
catch (WriteFailureException e)
{
writeMetrics.failures.mark();
writeMetricsForLevel(consistency_level).failures.mark();
Tracing.trace("Write failure; received {} of {} required replies", e.received, e.blockFor);
throw e;
}
finally
{
long latency = System.nanoTime() - startTime;
writeMetrics.addNano(latency);
writeMetricsForLevel(consistency_level).addNano(latency);
updateCoordinatorWriteLatencyTableMetric(mutations, latency);
}
}
private static void updateCoordinatorWriteLatencyTableMetric(Collection mutations, long latency)
{
if (null == mutations)
{
return;
}
try
{
//We could potentially pass a callback into performWrite. And add callback provision for mutateCounter or mutateAtomically (sendToHintedEndPoints)
//However, Trade off between write metric per CF accuracy vs performance hit due to callbacks. Similar issue exists with CoordinatorReadLatency metric.
mutations.stream()
.flatMap(m -> m.getTableIds().stream().map(tableId -> Keyspace.open(m.getKeyspaceName()).getColumnFamilyStore(tableId)))
.distinct()
.forEach(store -> store.metric.coordinatorWriteLatency.update(latency, TimeUnit.NANOSECONDS));
}
catch (Exception ex)
{
logger.warn("Exception occurred updating coordinatorWriteLatency metric", ex);
}
}
private static void syncWriteToBatchlog(Collection mutations, ReplicaPlan.ForTokenWrite replicaPlan, UUID uuid, long queryStartNanoTime)
throws WriteTimeoutException, WriteFailureException
{
WriteResponseHandler handler = new WriteResponseHandler(replicaPlan,
WriteType.BATCH_LOG,
queryStartNanoTime);
Batch batch = Batch.createLocal(uuid, FBUtilities.timestampMicros(), mutations);
Message message = Message.out(BATCH_STORE_REQ, batch);
for (Replica replica : replicaPlan.liveAndDown())
{
logger.trace("Sending batchlog store request {} to {} for {} mutations", batch.id, replica, batch.size());
if (replica.isSelf())
performLocally(Stage.MUTATION, replica, () -> BatchlogManager.store(batch), handler);
else
MessagingService.instance().sendWithCallback(message, replica.endpoint(), handler);
}
handler.get();
}
private static void asyncRemoveFromBatchlog(ReplicaPlan.ForTokenWrite replicaPlan, UUID uuid)
{
Message message = Message.out(Verb.BATCH_REMOVE_REQ, uuid);
for (Replica target : replicaPlan.contacts())
{
if (logger.isTraceEnabled())
logger.trace("Sending batchlog remove request {} to {}", uuid, target);
if (target.isSelf())
performLocally(Stage.MUTATION, target, () -> BatchlogManager.remove(uuid));
else
MessagingService.instance().send(message, target.endpoint());
}
}
private static void asyncWriteBatchedMutations(List wrappers, String localDataCenter, Stage stage)
{
for (WriteResponseHandlerWrapper wrapper : wrappers)
{
Replicas.temporaryAssertFull(wrapper.handler.replicaPlan.liveAndDown()); // TODO: CASSANDRA-14549
ReplicaPlan.ForTokenWrite replicas = wrapper.handler.replicaPlan.withContact(wrapper.handler.replicaPlan.liveAndDown());
try
{
sendToHintedReplicas(wrapper.mutation, replicas, wrapper.handler, localDataCenter, stage);
}
catch (OverloadedException | WriteTimeoutException e)
{
wrapper.handler.onFailure(FBUtilities.getBroadcastAddressAndPort(), RequestFailureReason.forException(e));
}
}
}
private static void syncWriteBatchedMutations(List wrappers, Stage stage)
throws WriteTimeoutException, OverloadedException
{
String localDataCenter = DatabaseDescriptor.getEndpointSnitch().getLocalDatacenter();
for (WriteResponseHandlerWrapper wrapper : wrappers)
{
EndpointsForToken sendTo = wrapper.handler.replicaPlan.liveAndDown();
Replicas.temporaryAssertFull(sendTo); // TODO: CASSANDRA-14549
sendToHintedReplicas(wrapper.mutation, wrapper.handler.replicaPlan.withContact(sendTo), wrapper.handler, localDataCenter, stage);
}
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 consistencyLevel 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
* @param queryStartNanoTime the value of System.nanoTime() when the query started to be processed
*/
public static AbstractWriteResponseHandler performWrite(IMutation mutation,
ConsistencyLevel consistencyLevel,
String localDataCenter,
WritePerformer performer,
Runnable callback,
WriteType writeType,
long queryStartNanoTime)
{
String keyspaceName = mutation.getKeyspaceName();
Keyspace keyspace = Keyspace.open(keyspaceName);
Token tk = mutation.key().getToken();
ReplicaPlan.ForTokenWrite replicaPlan = ReplicaPlans.forWrite(keyspace, consistencyLevel, tk, ReplicaPlans.writeNormal);
AbstractReplicationStrategy rs = replicaPlan.replicationStrategy();
AbstractWriteResponseHandler responseHandler = rs.getWriteResponseHandler(replicaPlan, callback, writeType, queryStartNanoTime);
performer.apply(mutation, replicaPlan, responseHandler, localDataCenter);
return responseHandler;
}
// same as performWrites except does not initiate writes (but does perform availability checks).
private static WriteResponseHandlerWrapper wrapBatchResponseHandler(Mutation mutation,
ConsistencyLevel consistencyLevel,
ConsistencyLevel batchConsistencyLevel,
WriteType writeType,
BatchlogResponseHandler.BatchlogCleanup cleanup,
long queryStartNanoTime)
{
Keyspace keyspace = Keyspace.open(mutation.getKeyspaceName());
Token tk = mutation.key().getToken();
ReplicaPlan.ForTokenWrite replicaPlan = ReplicaPlans.forWrite(keyspace, consistencyLevel, tk, ReplicaPlans.writeNormal);
AbstractReplicationStrategy rs = replicaPlan.replicationStrategy();
AbstractWriteResponseHandler writeHandler = rs.getWriteResponseHandler(replicaPlan,null, writeType, queryStartNanoTime);
BatchlogResponseHandler batchHandler = new BatchlogResponseHandler<>(writeHandler, batchConsistencyLevel.blockFor(rs), cleanup, queryStartNanoTime);
return new WriteResponseHandlerWrapper(batchHandler, mutation);
}
/**
* Same as performWrites except does not initiate writes (but does perform availability checks).
* Keeps track of ViewWriteMetrics
*/
private static WriteResponseHandlerWrapper wrapViewBatchResponseHandler(Mutation mutation,
ConsistencyLevel consistencyLevel,
ConsistencyLevel batchConsistencyLevel,
ReplicaLayout.ForTokenWrite liveAndDown,
AtomicLong baseComplete,
WriteType writeType,
BatchlogResponseHandler.BatchlogCleanup cleanup,
long queryStartNanoTime)
{
Keyspace keyspace = Keyspace.open(mutation.getKeyspaceName());
ReplicaPlan.ForTokenWrite replicaPlan = ReplicaPlans.forWrite(keyspace, consistencyLevel, liveAndDown, ReplicaPlans.writeAll);
AbstractReplicationStrategy replicationStrategy = replicaPlan.replicationStrategy();
AbstractWriteResponseHandler writeHandler = replicationStrategy.getWriteResponseHandler(replicaPlan, () -> {
long delay = Math.max(0, System.currentTimeMillis() - baseComplete.get());
viewWriteMetrics.viewWriteLatency.update(delay, MILLISECONDS);
}, writeType, queryStartNanoTime);
BatchlogResponseHandler batchHandler = new ViewWriteMetricsWrapped(writeHandler, batchConsistencyLevel.blockFor(replicationStrategy), cleanup, queryStartNanoTime);
return new WriteResponseHandlerWrapper(batchHandler, mutation);
}
// used by atomic_batch_mutate to decouple availability check from the write itself, caches consistency level and endpoints.
private static class WriteResponseHandlerWrapper
{
final BatchlogResponseHandler handler;
final Mutation mutation;
WriteResponseHandlerWrapper(BatchlogResponseHandler handler, Mutation mutation)
{
this.handler = handler;
this.mutation = mutation;
}
}
/**
* 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:
*
* {@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.
* }
*
*
* @throws OverloadedException if the hints cannot be written/enqueued
*/
public static void sendToHintedReplicas(final Mutation mutation,
ReplicaPlan.ForTokenWrite plan,
AbstractWriteResponseHandler responseHandler,
String localDataCenter,
Stage stage)
throws OverloadedException
{
// this dc replicas:
Collection localDc = null;
// extra-datacenter replicas, grouped by dc
Map> dcGroups = null;
// only need to create a Message for non-local writes
Message message = null;
boolean insertLocal = false;
Replica localReplica = null;
Collection endpointsToHint = null;
for (Replica destination : plan.contacts())
{
checkHintOverload(destination);
if (plan.isAlive(destination))
{
if (destination.isSelf())
{
insertLocal = true;
localReplica = destination;
}
else
{
// belongs on a different server
if (message == null)
message = Message.outWithFlag(MUTATION_REQ, mutation, MessageFlag.CALL_BACK_ON_FAILURE);
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))
{
if (localDc == null)
localDc = new ArrayList<>(plan.contacts().size());
localDc.add(destination);
}
else
{
if (dcGroups == null)
dcGroups = new HashMap<>();
Collection messages = dcGroups.get(dc);
if (messages == null)
messages = dcGroups.computeIfAbsent(dc, (v) -> new ArrayList<>(3)); // most DCs will have <= 3 replicas
messages.add(destination);
}
}
}
else
{
//Immediately mark the response as expired since the request will not be sent
responseHandler.expired();
if (shouldHint(destination))
{
if (endpointsToHint == null)
endpointsToHint = new ArrayList<>();
endpointsToHint.add(destination);
}
}
}
if (endpointsToHint != null)
submitHint(mutation, EndpointsForToken.copyOf(mutation.key().getToken(), endpointsToHint), responseHandler);
if (insertLocal)
{
Preconditions.checkNotNull(localReplica);
performLocally(stage, localReplica, mutation::apply, responseHandler);
}
if (localDc != null)
{
for (Replica destination : localDc)
MessagingService.instance().sendWriteWithCallback(message, destination, responseHandler, true);
}
if (dcGroups != null)
{
// for each datacenter, send the message to one node to relay the write to other replicas
for (Collection dcTargets : dcGroups.values())
sendMessagesToNonlocalDC(message, EndpointsForToken.copyOf(mutation.key().getToken(), dcTargets), responseHandler);
}
}
private static void checkHintOverload(Replica destination)
{
// 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.endpoint()).get() > 0 && shouldHint(destination)))
{
throw new OverloadedException("Too many in flight hints: " + StorageMetrics.totalHintsInProgress.getCount() +
" destination: " + destination +
" destination hints: " + getHintsInProgressFor(destination.endpoint()).get());
}
}
/*
* Send the message to the first replica of targets, and have it forward the message to others in its DC
*/
private static void sendMessagesToNonlocalDC(Message message,
EndpointsForToken targets,
AbstractWriteResponseHandler handler)
{
final Replica target;
if (targets.size() > 1)
{
target = targets.get(ThreadLocalRandom.current().nextInt(0, targets.size()));
EndpointsForToken forwardToReplicas = targets.filter(r -> r != target, targets.size());
for (Replica replica : forwardToReplicas)
{
MessagingService.instance().callbacks.addWithExpiration(handler, message, replica, handler.replicaPlan.consistencyLevel(), true);
logger.trace("Adding FWD message to {}@{}", message.id(), replica);
}
// starting with 4.0, use the same message id for all replicas
long[] messageIds = new long[forwardToReplicas.size()];
Arrays.fill(messageIds, message.id());
message = message.withForwardTo(new ForwardingInfo(forwardToReplicas.endpointList(), messageIds));
}
else
{
target = targets.get(0);
}
MessagingService.instance().sendWriteWithCallback(message, target, handler, true);
logger.trace("Sending message to {}@{}", message.id(), target);
}
private static void performLocally(Stage stage, Replica localReplica, final Runnable runnable)
{
stage.maybeExecuteImmediately(new LocalMutationRunnable(localReplica)
{
public void runMayThrow()
{
try
{
runnable.run();
}
catch (Exception ex)
{
logger.error("Failed to apply mutation locally : ", ex);
}
}
@Override
protected Verb verb()
{
return Verb.MUTATION_REQ;
}
});
}
private static void performLocally(Stage stage, Replica localReplica, final Runnable runnable, final RequestCallback handler)
{
stage.maybeExecuteImmediately(new LocalMutationRunnable(localReplica)
{
public void runMayThrow()
{
try
{
runnable.run();
handler.onResponse(null);
}
catch (Exception ex)
{
if (!(ex instanceof WriteTimeoutException))
logger.error("Failed to apply mutation locally : ", ex);
handler.onFailure(FBUtilities.getBroadcastAddressAndPort(), RequestFailureReason.forException(ex));
}
}
@Override
protected Verb verb()
{
return Verb.MUTATION_REQ;
}
});
}
/**
* 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 mutateCounter(CounterMutation cm, String localDataCenter, long queryStartNanoTime) throws UnavailableException, OverloadedException
{
Replica replica = findSuitableReplica(cm.getKeyspaceName(), cm.key(), localDataCenter, cm.consistency());
if (replica.isSelf())
{
return applyCounterMutationOnCoordinator(cm, localDataCenter, queryStartNanoTime);
}
else
{
// Exit now if we can't fulfill the CL here instead of forwarding to the leader replica
String keyspaceName = cm.getKeyspaceName();
Keyspace keyspace = Keyspace.open(keyspaceName);
Token tk = cm.key().getToken();
// we build this ONLY to perform the sufficiency check that happens on construction
ReplicaPlans.forWrite(keyspace, cm.consistency(), tk, ReplicaPlans.writeAll);
// Forward the actual update to the chosen leader replica
AbstractWriteResponseHandler responseHandler = new WriteResponseHandler<>(ReplicaPlans.forForwardingCounterWrite(keyspace, tk, replica),
WriteType.COUNTER, queryStartNanoTime);
Tracing.trace("Enqueuing counter update to {}", replica);
Message message = Message.outWithFlag(Verb.COUNTER_MUTATION_REQ, cm, MessageFlag.CALL_BACK_ON_FAILURE);
MessagingService.instance().sendWriteWithCallback(message, replica, 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 Replica findSuitableReplica(String keyspaceName, DecoratedKey key, String localDataCenter, ConsistencyLevel cl) throws UnavailableException
{
Keyspace keyspace = Keyspace.open(keyspaceName);
IEndpointSnitch snitch = DatabaseDescriptor.getEndpointSnitch();
AbstractReplicationStrategy replicationStrategy = keyspace.getReplicationStrategy();
EndpointsForToken replicas = replicationStrategy.getNaturalReplicasForToken(key);
// CASSANDRA-13043: filter out those endpoints not accepting clients yet, maybe because still bootstrapping
replicas = replicas.filter(replica -> StorageService.instance.isRpcReady(replica.endpoint()));
// CASSANDRA-17411: filter out endpoints that are not alive
replicas = replicas.filter(replica -> FailureDetector.instance.isAlive(replica.endpoint()));
// TODO have a way to compute the consistency level
if (replicas.isEmpty())
throw UnavailableException.create(cl, cl.blockFor(replicationStrategy), 0);
List localReplicas = new ArrayList<>(replicas.size());
for (Replica replica : replicas)
if (snitch.getDatacenter(replica).equals(localDataCenter))
localReplicas.add(replica);
if (localReplicas.isEmpty())
{
// If the consistency required is local then we should not involve other DCs
if (cl.isDatacenterLocal())
throw UnavailableException.create(cl, cl.blockFor(replicationStrategy), 0);
// No endpoint in local DC, pick the closest endpoint according to the snitch
replicas = snitch.sortedByProximity(FBUtilities.getBroadcastAddressAndPort(), replicas);
return replicas.get(0);
}
return localReplicas.get(ThreadLocalRandom.current().nextInt(localReplicas.size()));
}
// Must be called on a replica of the mutation. This replica becomes the
// leader of this mutation.
public static AbstractWriteResponseHandler applyCounterMutationOnLeader(CounterMutation cm, String localDataCenter, Runnable callback, long queryStartNanoTime)
throws UnavailableException, OverloadedException
{
return performWrite(cm, cm.consistency(), localDataCenter, counterWritePerformer, callback, WriteType.COUNTER, queryStartNanoTime);
}
// 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 applyCounterMutationOnCoordinator(CounterMutation cm, String localDataCenter, long queryStartNanoTime)
throws UnavailableException, OverloadedException
{
return performWrite(cm, cm.consistency(), localDataCenter, counterWriteOnCoordinatorPerformer, null, WriteType.COUNTER, queryStartNanoTime);
}
private static Runnable counterWriteTask(final IMutation mutation,
final ReplicaPlan.ForTokenWrite replicaPlan,
final AbstractWriteResponseHandler responseHandler,
final String localDataCenter)
{
return new DroppableRunnable(Verb.COUNTER_MUTATION_REQ)
{
@Override
public void runMayThrow() throws OverloadedException, WriteTimeoutException
{
assert mutation instanceof CounterMutation;
Mutation result = ((CounterMutation) mutation).applyCounterMutation();
responseHandler.onResponse(null);
sendToHintedReplicas(result, replicaPlan, responseHandler, localDataCenter, Stage.COUNTER_MUTATION);
}
};
}
private static boolean systemKeyspaceQuery(List cmds)
{
for (ReadCommand cmd : cmds)
if (!SchemaConstants.isLocalSystemKeyspace(cmd.metadata().keyspace))
return false;
return true;
}
public static RowIterator readOne(SinglePartitionReadCommand command, ConsistencyLevel consistencyLevel, long queryStartNanoTime)
throws UnavailableException, IsBootstrappingException, ReadFailureException, ReadTimeoutException, InvalidRequestException
{
return readOne(command, consistencyLevel, null, queryStartNanoTime);
}
public static RowIterator readOne(SinglePartitionReadCommand command, ConsistencyLevel consistencyLevel, ClientState state, long queryStartNanoTime)
throws UnavailableException, IsBootstrappingException, ReadFailureException, ReadTimeoutException, InvalidRequestException
{
return PartitionIterators.getOnlyElement(read(SinglePartitionReadCommand.Group.one(command), consistencyLevel, state, queryStartNanoTime), command);
}
public static PartitionIterator read(SinglePartitionReadCommand.Group group, ConsistencyLevel consistencyLevel, long queryStartNanoTime)
throws UnavailableException, IsBootstrappingException, ReadFailureException, ReadTimeoutException, InvalidRequestException
{
// When using serial CL, the ClientState should be provided
assert !consistencyLevel.isSerialConsistency();
return read(group, consistencyLevel, null, queryStartNanoTime);
}
/**
* 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 PartitionIterator read(SinglePartitionReadCommand.Group group, ConsistencyLevel consistencyLevel, ClientState state, long queryStartNanoTime)
throws UnavailableException, IsBootstrappingException, ReadFailureException, ReadTimeoutException, InvalidRequestException
{
if (StorageService.instance.isBootstrapMode() && !systemKeyspaceQuery(group.queries))
{
readMetrics.unavailables.mark();
readMetricsForLevel(consistencyLevel).unavailables.mark();
throw new IsBootstrappingException();
}
return consistencyLevel.isSerialConsistency()
? readWithPaxos(group, consistencyLevel, state, queryStartNanoTime)
: readRegular(group, consistencyLevel, queryStartNanoTime);
}
private static PartitionIterator readWithPaxos(SinglePartitionReadCommand.Group group, ConsistencyLevel consistencyLevel, ClientState state, long queryStartNanoTime)
throws InvalidRequestException, UnavailableException, ReadFailureException, ReadTimeoutException
{
assert state != null;
if (group.queries.size() > 1)
throw new InvalidRequestException("SERIAL/LOCAL_SERIAL consistency may only be requested for one partition at a time");
long start = System.nanoTime();
SinglePartitionReadCommand command = group.queries.get(0);
TableMetadata metadata = command.metadata();
DecoratedKey key = command.partitionKey();
// calculate the blockFor before repair any paxos round to avoid RS being altered in between.
int blockForRead = consistencyLevel.blockFor(Keyspace.open(metadata.keyspace).getReplicationStrategy());
PartitionIterator result = null;
try
{
final ConsistencyLevel consistencyForReplayCommitsOrFetch = consistencyLevel == ConsistencyLevel.LOCAL_SERIAL
? ConsistencyLevel.LOCAL_QUORUM
: ConsistencyLevel.QUORUM;
try
{
// Commit an empty update to make sure all in-progress updates that should be finished first is, _and_
// that no other in-progress can get resurrected.
Supplier> updateProposer =
disableSerialReadLinearizability
? () -> null
: () -> Pair.create(PartitionUpdate.emptyUpdate(metadata, key), null);
// When replaying, we commit at quorum/local quorum, as we want to be sure the following read (done at
// quorum/local_quorum) sees any replayed updates. Our own update is however empty, and those don't even
// get committed due to an optimiation described in doPaxos/beingRepairAndPaxos, so the commit
// consistency is irrelevant (we use ANY just to emphasis that we don't wait on our commit).
doPaxos(metadata,
key,
consistencyLevel,
consistencyForReplayCommitsOrFetch,
ConsistencyLevel.ANY,
state,
start,
casReadMetrics,
updateProposer);
}
catch (WriteTimeoutException e)
{
throw new ReadTimeoutException(consistencyLevel, 0, blockForRead, false);
}
catch (WriteFailureException e)
{
throw new ReadFailureException(consistencyLevel, e.received, e.blockFor, false, e.failureReasonByEndpoint);
}
result = fetchRows(group.queries, consistencyForReplayCommitsOrFetch, queryStartNanoTime);
}
catch (UnavailableException e)
{
readMetrics.unavailables.mark();
casReadMetrics.unavailables.mark();
readMetricsForLevel(consistencyLevel).unavailables.mark();
throw e;
}
catch (ReadTimeoutException e)
{
readMetrics.timeouts.mark();
casReadMetrics.timeouts.mark();
readMetricsForLevel(consistencyLevel).timeouts.mark();
throw e;
}
catch (ReadFailureException e)
{
readMetrics.failures.mark();
casReadMetrics.failures.mark();
readMetricsForLevel(consistencyLevel).failures.mark();
throw e;
}
finally
{
long latency = System.nanoTime() - start;
readMetrics.addNano(latency);
casReadMetrics.addNano(latency);
readMetricsForLevel(consistencyLevel).addNano(latency);
Keyspace.open(metadata.keyspace).getColumnFamilyStore(metadata.name).metric.coordinatorReadLatency.update(latency, TimeUnit.NANOSECONDS);
}
return result;
}
@SuppressWarnings("resource")
private static PartitionIterator readRegular(SinglePartitionReadCommand.Group group, ConsistencyLevel consistencyLevel, long queryStartNanoTime)
throws UnavailableException, ReadFailureException, ReadTimeoutException
{
long start = System.nanoTime();
try
{
PartitionIterator result = fetchRows(group.queries, consistencyLevel, queryStartNanoTime);
// Note that the only difference between the command in a group must be the partition key on which
// they applied.
boolean enforceStrictLiveness = group.queries.get(0).metadata().enforceStrictLiveness();
// If we have more than one command, then despite each read command honoring the limit, the total result
// might not honor it and so we should enforce it
if (group.queries.size() > 1)
result = group.limits().filter(result, group.nowInSec(), group.selectsFullPartition(), enforceStrictLiveness);
return result;
}
catch (UnavailableException e)
{
readMetrics.unavailables.mark();
readMetricsForLevel(consistencyLevel).unavailables.mark();
throw e;
}
catch (ReadTimeoutException e)
{
readMetrics.timeouts.mark();
readMetricsForLevel(consistencyLevel).timeouts.mark();
throw e;
}
catch (ReadFailureException e)
{
readMetrics.failures.mark();
readMetricsForLevel(consistencyLevel).failures.mark();
throw e;
}
finally
{
long latency = System.nanoTime() - start;
readMetrics.addNano(latency);
readMetricsForLevel(consistencyLevel).addNano(latency);
// TODO avoid giving every command the same latency number. Can fix this in CASSADRA-5329
for (ReadCommand command : group.queries)
Keyspace.openAndGetStore(command.metadata()).metric.coordinatorReadLatency.update(latency, TimeUnit.NANOSECONDS);
}
}
public static PartitionIterator concatAndBlockOnRepair(List iterators, List> repairs)
{
PartitionIterator concatenated = PartitionIterators.concat(iterators);
if (repairs.isEmpty())
return concatenated;
return new PartitionIterator()
{
public void close()
{
concatenated.close();
repairs.forEach(ReadRepair::maybeSendAdditionalWrites);
repairs.forEach(ReadRepair::awaitWrites);
}
public boolean hasNext()
{
return concatenated.hasNext();
}
public RowIterator next()
{
return concatenated.next();
}
};
}
/**
* 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 PartitionIterator fetchRows(List commands, ConsistencyLevel consistencyLevel, long queryStartNanoTime)
throws UnavailableException, ReadFailureException, ReadTimeoutException
{
int cmdCount = commands.size();
AbstractReadExecutor[] reads = new AbstractReadExecutor[cmdCount];
// Get the replica locations, sorted by response time according to the snitch, and create a read executor
// for type of speculation we'll use in this read
for (int i=0; i results = new ArrayList<>(cmdCount);
List> repairs = new ArrayList<>(cmdCount);
for (int i=0; i> getSchemaVersions()
{
return describeSchemaVersions(false);
}
public Map> getSchemaVersionsWithPort()
{
return describeSchemaVersions(true);
}
/**
* 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> describeSchemaVersions(boolean withPort)
{
final String myVersion = Schema.instance.getVersion().toString();
final Map versions = new ConcurrentHashMap<>();
final Set liveHosts = Gossiper.instance.getLiveMembers();
final CountDownLatch latch = new CountDownLatch(liveHosts.size());
RequestCallback cb = message ->
{
// record the response from the remote node.
versions.put(message.from(), message.payload);
latch.countDown();
};
// an empty message acts as a request to the SchemaVersionVerbHandler.
Message message = Message.out(Verb.SCHEMA_VERSION_REQ, noPayload);
for (InetAddressAndPort endpoint : liveHosts)
MessagingService.instance().sendWithCallback(message, endpoint, cb);
try
{
// wait for as long as possible. timeout-1s if possible.
latch.await(DatabaseDescriptor.getRpcTimeout(NANOSECONDS), NANOSECONDS);
}
catch (InterruptedException ex)
{
throw new AssertionError("This latch shouldn't have been interrupted.");
}
// maps versions to hosts that are on that version.
Map> results = new HashMap>();
Iterable allHosts = Iterables.concat(Gossiper.instance.getLiveMembers(), Gossiper.instance.getUnreachableMembers());
for (InetAddressAndPort host : allHosts)
{
UUID version = versions.get(host);
String stringVersion = version == null ? UNREACHABLE : version.toString();
List hosts = results.get(stringVersion);
if (hosts == null)
{
hosts = new ArrayList();
results.put(stringVersion, hosts);
}
hosts.add(host.getHostAddress(withPort));
}
// 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> 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;
}
public boolean getHintedHandoffEnabled()
{
return DatabaseDescriptor.hintedHandoffEnabled();
}
public void setHintedHandoffEnabled(boolean b)
{
synchronized (StorageService.instance)
{
if (b)
StorageService.instance.checkServiceAllowedToStart("hinted handoff");
DatabaseDescriptor.setHintedHandoffEnabled(b);
}
}
public void enableHintsForDC(String dc)
{
DatabaseDescriptor.enableHintsForDC(dc);
}
public void disableHintsForDC(String dc)
{
DatabaseDescriptor.disableHintsForDC(dc);
}
public Set getHintedHandoffDisabledDCs()
{
return DatabaseDescriptor.hintedHandoffDisabledDCs();
}
public int getMaxHintWindow()
{
return DatabaseDescriptor.getMaxHintWindow();
}
public void setMaxHintWindow(int ms)
{
DatabaseDescriptor.setMaxHintWindow(ms);
}
public static boolean shouldHint(Replica replica)
{
if (!DatabaseDescriptor.hintedHandoffEnabled())
return false;
if (replica.isTransient() || replica.isSelf())
return false;
Set disabledDCs = DatabaseDescriptor.hintedHandoffDisabledDCs();
if (!disabledDCs.isEmpty())
{
final String dc = DatabaseDescriptor.getEndpointSnitch().getDatacenter(replica);
if (disabledDCs.contains(dc))
{
Tracing.trace("Not hinting {} since its data center {} has been disabled {}", replica, dc, disabledDCs);
return false;
}
}
boolean hintWindowExpired = Gossiper.instance.getEndpointDowntime(replica.endpoint()) > DatabaseDescriptor.getMaxHintWindow();
if (hintWindowExpired)
{
HintsService.instance.metrics.incrPastWindow(replica.endpoint());
Tracing.trace("Not hinting {} which has been down {} ms", replica, Gossiper.instance.getEndpointDowntime(replica.endpoint()));
}
return !hintWindowExpired;
}
/**
* 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
*/
public static void truncateBlocking(String keyspace, String cfname) throws UnavailableException, TimeoutException
{
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 UnavailableException.create(ConsistencyLevel.ALL, liveMembers + Gossiper.instance.getUnreachableMembers().size(), liveMembers);
}
Set 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);
Message message = Message.out(TRUNCATE_REQ, new TruncateRequest(keyspace, cfname));
for (InetAddressAndPort endpoint : allEndpoints)
MessagingService.instance().sendWithCallback(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,
ReplicaPlan.ForTokenWrite targets,
AbstractWriteResponseHandler responseHandler,
String localDataCenter) throws OverloadedException;
}
/**
* This class captures metrics for views writes.
*/
private static class ViewWriteMetricsWrapped extends BatchlogResponseHandler
{
public ViewWriteMetricsWrapped(AbstractWriteResponseHandler writeHandler, int i, BatchlogCleanup cleanup, long queryStartNanoTime)
{
super(writeHandler, i, cleanup, queryStartNanoTime);
viewWriteMetrics.viewReplicasAttempted.inc(candidateReplicaCount());
}
public void onResponse(Message msg)
{
super.onResponse(msg);
viewWriteMetrics.viewReplicasSuccess.inc();
}
}
/**
* A Runnable that aborts if it doesn't start running before it times out
*/
private static abstract class DroppableRunnable implements Runnable
{
final long approxCreationTimeNanos;
final Verb verb;
public DroppableRunnable(Verb verb)
{
this.approxCreationTimeNanos = MonotonicClock.approxTime.now();
this.verb = verb;
}
public final void run()
{
long approxCurrentTimeNanos = MonotonicClock.approxTime.now();
long expirationTimeNanos = verb.expiresAtNanos(approxCreationTimeNanos);
if (approxCurrentTimeNanos > expirationTimeNanos)
{
long timeTakenNanos = approxCurrentTimeNanos - approxCreationTimeNanos;
MessagingService.instance().metrics.recordSelfDroppedMessage(verb, timeTakenNanos, NANOSECONDS);
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 approxCreationTimeNanos = MonotonicClock.approxTime.now();
private final Replica localReplica;
LocalMutationRunnable(Replica localReplica)
{
this.localReplica = localReplica;
}
public final void run()
{
final Verb verb = verb();
long nowNanos = MonotonicClock.approxTime.now();
long expirationTimeNanos = verb.expiresAtNanos(approxCreationTimeNanos);
if (nowNanos > expirationTimeNanos)
{
long timeTakenNanos = nowNanos - approxCreationTimeNanos;
MessagingService.instance().metrics.recordSelfDroppedMessage(Verb.MUTATION_REQ, timeTakenNanos, NANOSECONDS);
HintRunnable runnable = new HintRunnable(EndpointsForToken.of(localReplica.range().right, localReplica))
{
protected void runMayThrow() throws Exception
{
LocalMutationRunnable.this.runMayThrow();
}
};
submitHint(runnable);
return;
}
try
{
runMayThrow();
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
abstract protected 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 EndpointsForToken targets;
protected HintRunnable(EndpointsForToken targets)
{
this.targets = targets;
}
public void run()
{
try
{
runMayThrow();
}
catch (Exception e)
{
throw new RuntimeException(e);
}
finally
{
StorageMetrics.totalHintsInProgress.dec(targets.size());
for (InetAddressAndPort target : targets.endpoints())
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");
}
private static AtomicInteger getHintsInProgressFor(InetAddressAndPort destination)
{
try
{
return hintsInProgress.load(destination);
}
catch (Exception e)
{
throw new AssertionError(e);
}
}
public static Future submitHint(Mutation mutation, Replica target, AbstractWriteResponseHandler responseHandler)
{
return submitHint(mutation, EndpointsForToken.of(target.range().right, target), responseHandler);
}
public static Future submitHint(Mutation mutation,
EndpointsForToken targets,
AbstractWriteResponseHandler responseHandler)
{
Replicas.assertFull(targets); // hints should not be written for transient replicas
HintRunnable runnable = new HintRunnable(targets)
{
public void runMayThrow()
{
Set validTargets = new HashSet<>(targets.size());
Set hostIds = new HashSet<>(targets.size());
for (InetAddressAndPort target : targets.endpoints())
{
UUID hostId = StorageService.instance.getHostIdForEndpoint(target);
if (hostId != null)
{
hostIds.add(hostId);
validTargets.add(target);
}
else
logger.debug("Discarding hint for endpoint not part of ring: {}", target);
}
logger.trace("Adding hints for {}", validTargets);
HintsService.instance.write(hostIds, Hint.create(mutation, System.currentTimeMillis()));
validTargets.forEach(HintsService.instance.metrics::incrCreatedHints);
// Notify the handler only for CL == ANY
if (responseHandler != null && responseHandler.replicaPlan.consistencyLevel() == ConsistencyLevel.ANY)
responseHandler.onResponse(null);
}
};
return submitHint(runnable);
}
private static Future submitHint(HintRunnable runnable)
{
StorageMetrics.totalHintsInProgress.inc(runnable.targets.size());
for (Replica target : runnable.targets)
getHintsInProgressFor(target.endpoint()).incrementAndGet();
return (Future) Stage.MUTATION.submit(runnable);
}
public Long getRpcTimeout() { return DatabaseDescriptor.getRpcTimeout(MILLISECONDS); }
public void setRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setRpcTimeout(timeoutInMillis); }
public Long getReadRpcTimeout() { return DatabaseDescriptor.getReadRpcTimeout(MILLISECONDS); }
public void setReadRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setReadRpcTimeout(timeoutInMillis); }
public Long getWriteRpcTimeout() { return DatabaseDescriptor.getWriteRpcTimeout(MILLISECONDS); }
public void setWriteRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setWriteRpcTimeout(timeoutInMillis); }
public Long getCounterWriteRpcTimeout() { return DatabaseDescriptor.getCounterWriteRpcTimeout(MILLISECONDS); }
public void setCounterWriteRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setCounterWriteRpcTimeout(timeoutInMillis); }
public Long getCasContentionTimeout() { return DatabaseDescriptor.getCasContentionTimeout(MILLISECONDS); }
public void setCasContentionTimeout(Long timeoutInMillis) { DatabaseDescriptor.setCasContentionTimeout(timeoutInMillis); }
public Long getRangeRpcTimeout() { return DatabaseDescriptor.getRangeRpcTimeout(MILLISECONDS); }
public void setRangeRpcTimeout(Long timeoutInMillis) { DatabaseDescriptor.setRangeRpcTimeout(timeoutInMillis); }
public Long getTruncateRpcTimeout() { return DatabaseDescriptor.getTruncateRpcTimeout(MILLISECONDS); }
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();
}
public int getNumberOfTables()
{
return Schema.instance.getNumberOfTables();
}
public String getIdealConsistencyLevel()
{
return Objects.toString(DatabaseDescriptor.getIdealConsistencyLevel(), "");
}
public String setIdealConsistencyLevel(String cl)
{
ConsistencyLevel original = DatabaseDescriptor.getIdealConsistencyLevel();
ConsistencyLevel newCL = ConsistencyLevel.valueOf(cl.trim().toUpperCase());
DatabaseDescriptor.setIdealConsistencyLevel(newCL);
return String.format("Updating ideal consistency level new value: %s old value %s", newCL, original.toString());
}
@Deprecated
public int getOtcBacklogExpirationInterval() {
return 0;
}
@Deprecated
public void setOtcBacklogExpirationInterval(int intervalInMillis) { }
@Override
public void enableRepairedDataTrackingForRangeReads()
{
DatabaseDescriptor.setRepairedDataTrackingForRangeReadsEnabled(true);
}
@Override
public void disableRepairedDataTrackingForRangeReads()
{
DatabaseDescriptor.setRepairedDataTrackingForRangeReadsEnabled(false);
}
@Override
public boolean getRepairedDataTrackingEnabledForRangeReads()
{
return DatabaseDescriptor.getRepairedDataTrackingForRangeReadsEnabled();
}
@Override
public void enableRepairedDataTrackingForPartitionReads()
{
DatabaseDescriptor.setRepairedDataTrackingForPartitionReadsEnabled(true);
}
@Override
public void disableRepairedDataTrackingForPartitionReads()
{
DatabaseDescriptor.setRepairedDataTrackingForPartitionReadsEnabled(false);
}
@Override
public boolean getRepairedDataTrackingEnabledForPartitionReads()
{
return DatabaseDescriptor.getRepairedDataTrackingForPartitionReadsEnabled();
}
@Override
public void enableReportingUnconfirmedRepairedDataMismatches()
{
DatabaseDescriptor.reportUnconfirmedRepairedDataMismatches(true);
}
@Override
public void disableReportingUnconfirmedRepairedDataMismatches()
{
DatabaseDescriptor.reportUnconfirmedRepairedDataMismatches(false);
}
@Override
public boolean getReportingUnconfirmedRepairedDataMismatchesEnabled()
{
return DatabaseDescriptor.reportUnconfirmedRepairedDataMismatches();
}
@Override
public boolean getSnapshotOnRepairedDataMismatchEnabled()
{
return DatabaseDescriptor.snapshotOnRepairedDataMismatch();
}
@Override
public void enableSnapshotOnRepairedDataMismatch()
{
DatabaseDescriptor.setSnapshotOnRepairedDataMismatch(true);
}
@Override
public void disableSnapshotOnRepairedDataMismatch()
{
DatabaseDescriptor.setSnapshotOnRepairedDataMismatch(false);
}
static class PaxosBallotAndContention
{
final UUID ballot;
final int contentions;
PaxosBallotAndContention(UUID ballot, int contentions)
{
this.ballot = ballot;
this.contentions = contentions;
}
@Override
public final int hashCode()
{
int hashCode = 31 + (ballot == null ? 0 : ballot.hashCode());
return 31 * hashCode * this.contentions;
}
@Override
public final boolean equals(Object o)
{
if(!(o instanceof PaxosBallotAndContention))
return false;
PaxosBallotAndContention that = (PaxosBallotAndContention)o;
// handles nulls properly
return Objects.equals(ballot, that.ballot) && contentions == that.contentions;
}
}
@Override
public boolean getSnapshotOnDuplicateRowDetectionEnabled()
{
return DatabaseDescriptor.snapshotOnDuplicateRowDetection();
}
@Override
public void enableSnapshotOnDuplicateRowDetection()
{
DatabaseDescriptor.setSnapshotOnDuplicateRowDetection(true);
}
@Override
public void disableSnapshotOnDuplicateRowDetection()
{
DatabaseDescriptor.setSnapshotOnDuplicateRowDetection(false);
}
@Override
public boolean getCheckForDuplicateRowsDuringReads()
{
return DatabaseDescriptor.checkForDuplicateRowsDuringReads();
}
@Override
public void enableCheckForDuplicateRowsDuringReads()
{
DatabaseDescriptor.setCheckForDuplicateRowsDuringReads(true);
}
@Override
public void disableCheckForDuplicateRowsDuringReads()
{
DatabaseDescriptor.setCheckForDuplicateRowsDuringReads(false);
}
@Override
public boolean getCheckForDuplicateRowsDuringCompaction()
{
return DatabaseDescriptor.checkForDuplicateRowsDuringCompaction();
}
@Override
public void enableCheckForDuplicateRowsDuringCompaction()
{
DatabaseDescriptor.setCheckForDuplicateRowsDuringCompaction(true);
}
@Override
public void disableCheckForDuplicateRowsDuringCompaction()
{
DatabaseDescriptor.setCheckForDuplicateRowsDuringCompaction(false);
}
}