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The Apache Cassandra Project develops a highly scalable second-generation distributed database, bringing together Dynamo's fully distributed design and Bigtable's ColumnFamily-based data model.

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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.EnumMap;
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.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.CASClientWriteRequestMetrics;
import org.apache.cassandra.metrics.ClientRequestMetrics;
import org.apache.cassandra.metrics.ClientWriteRequestMetrics;
import org.apache.cassandra.metrics.ReadRepairMetrics;
import org.apache.cassandra.metrics.StorageMetrics;
import org.apache.cassandra.metrics.ViewWriteMetrics;
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.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 ClientRequestMetrics readMetrics = new ClientRequestMetrics("Read");
    private static final ClientWriteRequestMetrics writeMetrics = new ClientWriteRequestMetrics("Write");
    private static final CASClientWriteRequestMetrics casWriteMetrics = new CASClientWriteRequestMetrics("CASWrite");
    private static final CASClientRequestMetrics casReadMetrics = new CASClientRequestMetrics("CASRead");
    private static final ViewWriteMetrics viewWriteMetrics = new ViewWriteMetrics("ViewWrite");
    private static final Map readMetricsMap = new EnumMap<>(ConsistencyLevel.class);
    private static final Map writeMetricsMap = new EnumMap<>(ConsistencyLevel.class);

    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));
        };

        for(ConsistencyLevel level : ConsistencyLevel.values())
        {
            readMetricsMap.put(level, new ClientRequestMetrics("Read-" + level.name()));
            writeMetricsMap.put(level, new ClientWriteRequestMetrics("Write-" + level.name()));
        }

        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);
                writeMetricsMap.get(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();
            writeMetricsMap.get(consistencyForPaxos).timeouts.mark();
            throw new CasWriteTimeoutException(wte.writeType, wte.consistency, wte.received, wte.blockFor, wte.contentions);
        }
        catch (ReadTimeoutException e)
        {
            casWriteMetrics.timeouts.mark();
            writeMetricsMap.get(consistencyForPaxos).timeouts.mark();
            throw e;
        }
        catch (WriteFailureException | ReadFailureException e)
        {
            casWriteMetrics.failures.mark();
            writeMetricsMap.get(consistencyForPaxos).failures.mark();
            throw e;
        }
        catch (UnavailableException e)
        {
            casWriteMetrics.unavailables.mark();
            writeMetricsMap.get(consistencyForPaxos).unavailables.mark();
            throw e;
        }
        finally
        {
            final long latency = System.nanoTime() - startTimeForMetrics;
            casWriteMetrics.addNano(latency);
            writeMetricsMap.get(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(); writeMetricsMap.get(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(); writeMetricsMap.get(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(); writeMetricsMap.get(consistencyLevel).unavailables.mark(); Tracing.trace("Unavailable"); throw e; } catch (OverloadedException e) { writeMetrics.unavailables.mark(); writeMetricsMap.get(consistencyLevel).unavailables.mark(); Tracing.trace("Overloaded"); throw e; } finally { long latency = System.nanoTime() - startTime; writeMetrics.addNano(latency); writeMetricsMap.get(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); cleanup.ackMutation(); } 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); writeMetricsMap.get(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(); writeMetricsMap.get(consistency_level).unavailables.mark(); Tracing.trace("Unavailable"); throw e; } catch (WriteTimeoutException e) { writeMetrics.timeouts.mark(); writeMetricsMap.get(consistency_level).timeouts.mark(); Tracing.trace("Write timeout; received {} of {} required replies", e.received, e.blockFor); throw e; } catch (WriteFailureException e) { writeMetrics.failures.mark(); writeMetricsMap.get(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); writeMetricsMap.get(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; List backPressureHosts = 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); } if (backPressureHosts == null) backPressureHosts = new ArrayList<>(plan.contacts().size()); backPressureHosts.add(destination.endpoint()); } } 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())); // 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(); readMetricsMap.get(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(); readMetricsMap.get(consistencyLevel).unavailables.mark(); throw e; } catch (ReadTimeoutException e) { readMetrics.timeouts.mark(); casReadMetrics.timeouts.mark(); readMetricsMap.get(consistencyLevel).timeouts.mark(); throw e; } catch (ReadFailureException e) { readMetrics.failures.mark(); casReadMetrics.failures.mark(); readMetricsMap.get(consistencyLevel).failures.mark(); throw e; } finally { long latency = System.nanoTime() - start; readMetrics.addNano(latency); casReadMetrics.addNano(latency); readMetricsMap.get(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(); readMetricsMap.get(consistencyLevel).unavailables.mark(); throw e; } catch (ReadTimeoutException e) { readMetrics.timeouts.mark(); readMetricsMap.get(consistencyLevel).timeouts.mark(); throw e; } catch (ReadFailureException e) { readMetrics.failures.mark(); readMetricsMap.get(consistencyLevel).failures.mark(); throw e; } finally { long latency = System.nanoTime() - start; readMetrics.addNano(latency); readMetricsMap.get(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); } }




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