jihoonson commented on a change in pull request #6901: Introduce published segment cache in broker URL: https://github.com/apache/incubator-druid/pull/6901#discussion_r251608611
########## File path: server/src/main/java/org/apache/druid/client/MetadataSegmentView.java ########## @@ -0,0 +1,174 @@ +/* + * 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.druid.client; + +import com.fasterxml.jackson.core.type.TypeReference; +import com.fasterxml.jackson.databind.JavaType; +import com.fasterxml.jackson.databind.ObjectMapper; +import com.google.common.util.concurrent.ListenableFuture; +import com.google.inject.Inject; +import org.apache.druid.client.coordinator.Coordinator; +import org.apache.druid.discovery.DruidLeaderClient; +import org.apache.druid.guice.ManageLifecycle; +import org.apache.druid.java.util.common.DateTimes; +import org.apache.druid.java.util.common.StringUtils; +import org.apache.druid.java.util.common.concurrent.Execs; +import org.apache.druid.java.util.common.lifecycle.LifecycleStart; +import org.apache.druid.java.util.common.lifecycle.LifecycleStop; +import org.apache.druid.java.util.emitter.EmittingLogger; +import org.apache.druid.java.util.http.client.Request; +import org.apache.druid.server.coordinator.BytesAccumulatingResponseHandler; +import org.apache.druid.timeline.DataSegment; +import org.jboss.netty.handler.codec.http.HttpMethod; +import org.joda.time.DateTime; + +import java.io.IOException; +import java.io.InputStream; +import java.util.Iterator; +import java.util.Map; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.TimeUnit; + +@ManageLifecycle +public class MetadataSegmentView +{ + + private static final int DEFAULT_POLL_PERIOD_IN_MS = 60000; + private static final EmittingLogger log = new EmittingLogger(MetadataSegmentView.class); + + private final DruidLeaderClient coordinatorDruidLeaderClient; + private final ObjectMapper jsonMapper; + private final BytesAccumulatingResponseHandler responseHandler; + private final BrokerSegmentWatcherConfig segmentWatcherConfig; + + private final Map<DataSegment, DateTime> publishedSegments = new ConcurrentHashMap<>(); + private ScheduledExecutorService scheduledExec; + + @Inject + public MetadataSegmentView( + final @Coordinator DruidLeaderClient druidLeaderClient, + ObjectMapper jsonMapper, + BytesAccumulatingResponseHandler responseHandler, + final BrokerSegmentWatcherConfig segmentWatcherConfig + ) + { + this.coordinatorDruidLeaderClient = druidLeaderClient; + this.jsonMapper = jsonMapper; + this.responseHandler = responseHandler; + this.segmentWatcherConfig = segmentWatcherConfig; + } + + @LifecycleStart + public void start() + { + scheduledExec = Execs.scheduledSingleThreaded("MetadataSegmentView-Cache--%d"); + scheduledExec.scheduleWithFixedDelay( + () -> poll(), + 0, + DEFAULT_POLL_PERIOD_IN_MS, + TimeUnit.MILLISECONDS + ); + } + + @LifecycleStop + public void stop() + { + scheduledExec.shutdownNow(); + scheduledExec = null; + } + + private void poll() + { + log.info("polling published segments from coordinator"); + //get authorized published segments from coordinator + final JsonParserIterator<DataSegment> metadataSegments = getMetadataSegments( + coordinatorDruidLeaderClient, + jsonMapper, + responseHandler + ); + + final DateTime ts = DateTimes.nowUtc(); + while (metadataSegments.hasNext()) { + final DataSegment currentSegment = metadataSegments.next(); + final DataSegment interned; + if (currentSegment.getSize() > 0) { + interned = DataSegmentInterner.HISTORICAL_INTERNER.intern(currentSegment); + } else { + interned = DataSegmentInterner.REALTIME_INTERNER.intern(currentSegment); + } + publishedSegments.put(interned, ts); + } + // filter the segments from cache which may not be present in subsequent polling + publishedSegments.values().removeIf(v -> v != ts); Review comment: Would you elaborate more on what this is doing? And what happens if someone reads a segment by calling `getPublishedSegments` which is supposed to be removed but haven't yet? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
