keith-turner commented on code in PR #3929: URL: https://github.com/apache/accumulo/pull/3929#discussion_r1383690776
########## server/base/src/main/java/org/apache/accumulo/server/metadata/AsyncConditionalTabletsMutatorImpl.java: ########## @@ -0,0 +1,95 @@ +/* + * 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 + * + * https://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.accumulo.server.metadata; + +import java.util.Map; +import java.util.Objects; +import java.util.concurrent.ExecutionException; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.Future; +import java.util.function.BiConsumer; + +import org.apache.accumulo.core.dataImpl.KeyExtent; +import org.apache.accumulo.core.metadata.schema.Ample; +import org.apache.accumulo.server.ServerContext; + +public class AsyncConditionalTabletsMutatorImpl implements Ample.AsyncConditionalTabletsMutator { + private final BiConsumer<KeyExtent,Ample.ConditionalResult> resultsConsumer; + private final ExecutorService executor; + private Future<Map<KeyExtent,Ample.ConditionalResult>> backgroundProcessing = null; + private ConditionalTabletsMutatorImpl bufferingMutator; + private final ServerContext context; + private long mutatedTablets = 0; + + public static final int BATCH_SIZE = 1000; + + AsyncConditionalTabletsMutatorImpl(ServerContext context, + BiConsumer<KeyExtent,Ample.ConditionalResult> resultsConsumer) { + this.resultsConsumer = Objects.requireNonNull(resultsConsumer); + this.bufferingMutator = new ConditionalTabletsMutatorImpl(context); + this.context = context; + this.executor = Executors.newSingleThreadExecutor(); + + } + + @Override + public Ample.OperationRequirements mutateTablet(KeyExtent extent) { + if (mutatedTablets > BATCH_SIZE) { + if (backgroundProcessing != null) { + // a previous batch of mutations was submitted for processing so wait on it. + try { + backgroundProcessing.get().forEach(resultsConsumer); + } catch (InterruptedException | ExecutionException e) { + throw new IllegalStateException(e); + } + } + + // Spin up processing of the mutations submitted so far in a background thread. Must copy the + // reference for the background thread because a new one is about to be created. + var bufferingMutatorRef = bufferingMutator; + backgroundProcessing = executor.submit(() -> { + var result = bufferingMutatorRef.process(); + bufferingMutatorRef.close(); + return result; + }); + + bufferingMutator = new ConditionalTabletsMutatorImpl(context); + mutatedTablets = 0; + } + mutatedTablets++; + return bufferingMutator.mutateTablet(extent); + } + + @Override + public void close() { + if (backgroundProcessing != null) { Review Comment: This should definitely only be called by a single thread. I added a javadoc comment in 08608df. I also experimented with the `@NotThreadSafe` annotation for the class, however in experiments spotbugs did not trigger when the class was misused. I also could not find any spotbugs documentation for the annotation. So I ended up not adding that annotation to the class. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
