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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.reads.repair;
import java.util.Map;
import java.util.function.Consumer;
import java.util.function.Supplier;
import org.apache.cassandra.db.DecoratedKey;
import org.apache.cassandra.locator.Endpoints;
import org.apache.cassandra.db.Mutation;
import org.apache.cassandra.db.ReadCommand;
import org.apache.cassandra.db.partitions.PartitionIterator;
import org.apache.cassandra.db.partitions.UnfilteredPartitionIterators;
import org.apache.cassandra.exceptions.ReadTimeoutException;
import org.apache.cassandra.locator.Replica;
import org.apache.cassandra.locator.ReplicaPlan;
import org.apache.cassandra.service.reads.DigestResolver;
public interface ReadRepair<E extends Endpoints<E>, P extends ReplicaPlan.ForRead<E>>
{
public interface Factory
{
<E extends Endpoints<E>, P extends ReplicaPlan.ForRead<E>>
ReadRepair<E, P> create(ReadCommand command, ReplicaPlan.Shared<E, P> replicaPlan, long queryStartNanoTime);
}
static <E extends Endpoints<E>, P extends ReplicaPlan.ForRead<E>>
ReadRepair<E, P> create(ReadCommand command, ReplicaPlan.Shared<E, P> replicaPlan, long queryStartNanoTime)
{
return command.metadata().params.readRepair.create(command, replicaPlan, queryStartNanoTime);
}
/**
* Used by DataResolver to generate corrections as the partition iterator is consumed
*/
UnfilteredPartitionIterators.MergeListener getMergeListener(P replicaPlan);
/**
* Called when the digests from the initial read don't match. Reads may block on the
* repair started by this method.
* @param digestResolver supplied so we can get the original data response
* @param resultConsumer hook for the repair to set it's result on completion
*/
public void startRepair(DigestResolver<E, P> digestResolver, Consumer<PartitionIterator> resultConsumer);
/**
* Block on the reads (or timeout) sent out in {@link ReadRepair#startRepair}
*/
public void awaitReads() throws ReadTimeoutException;
/**
* if it looks like we might not receive data requests from everyone in time, send additional requests
* to additional replicas not contacted in the initial full data read. If the collection of nodes that
* end up responding in time end up agreeing on the data, and we don't consider the response from the
* disagreeing replica that triggered the read repair, that's ok, since the disagreeing data would not
* have been successfully written and won't be included in the response the the client, preserving the
* expectation of monotonic quorum reads
*/
public void maybeSendAdditionalReads();
/**
* If it looks like we might not receive acks for all the repair mutations we sent out, combine all
* the unacked mutations and send them to the minority of nodes not involved in the read repair data
* read / write cycle. We will accept acks from them in lieu of acks from the initial mutations sent
* out, so long as we receive the same number of acks as repair mutations transmitted. This prevents
* misbehaving nodes from killing a quorum read, while continuing to guarantee monotonic quorum reads
*/
public void maybeSendAdditionalWrites();
/**
* Block on any mutations (or timeout) we sent out to repair replicas in {@link ReadRepair#repairPartition}
*/
public void awaitWrites();
/**
* Repairs a partition _after_ receiving data responses. This method receives replica list, since
* we will block repair only on the replicas that have responded.
*/
void repairPartition(DecoratedKey partitionKey, Map<Replica, Mutation> mutations, ReplicaPlan.ForTokenWrite writePlan);
}