jihoonson commented on a change in pull request #10082: URL: https://github.com/apache/druid/pull/10082#discussion_r446451237
########## File path: server/src/test/java/org/apache/druid/query/RetryQueryRunnerTest.java ########## @@ -0,0 +1,326 @@ +/* + * 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.query; + +import com.fasterxml.jackson.databind.ObjectMapper; +import com.google.common.collect.ImmutableList; +import com.google.common.collect.ImmutableMap; +import org.apache.druid.client.CachingClusteredClient; +import org.apache.druid.client.DirectDruidClient; +import org.apache.druid.client.DruidServer; +import org.apache.druid.client.SimpleServerView; +import org.apache.druid.client.TestHttpClient; +import org.apache.druid.client.TestHttpClient.SimpleServerManager; +import org.apache.druid.client.cache.CacheConfig; +import org.apache.druid.client.cache.CachePopulatorStats; +import org.apache.druid.client.cache.ForegroundCachePopulator; +import org.apache.druid.client.cache.MapCache; +import org.apache.druid.guice.http.DruidHttpClientConfig; +import org.apache.druid.jackson.DefaultObjectMapper; +import org.apache.druid.java.util.common.DateTimes; +import org.apache.druid.java.util.common.Pair; +import org.apache.druid.java.util.common.granularity.Granularities; +import org.apache.druid.java.util.common.guava.Sequence; +import org.apache.druid.java.util.common.io.Closer; +import org.apache.druid.query.aggregation.CountAggregatorFactory; +import org.apache.druid.query.timeseries.TimeseriesQuery; +import org.apache.druid.query.timeseries.TimeseriesResultValue; +import org.apache.druid.segment.QueryableIndex; +import org.apache.druid.segment.SegmentMissingException; +import org.apache.druid.segment.generator.GeneratorBasicSchemas; +import org.apache.druid.segment.generator.GeneratorSchemaInfo; +import org.apache.druid.segment.generator.SegmentGenerator; +import org.apache.druid.server.QueryStackTests; +import org.apache.druid.timeline.DataSegment; +import org.apache.druid.timeline.SegmentId; +import org.apache.druid.timeline.partition.NumberedShardSpec; +import org.joda.time.Interval; +import org.junit.After; +import org.junit.AfterClass; +import org.junit.Assert; +import org.junit.Before; +import org.junit.Rule; +import org.junit.Test; +import org.junit.rules.ExpectedException; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.ForkJoinPool; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +public class RetryQueryRunnerTest +{ + private static final Closer CLOSER = Closer.create(); + private static final String DATASOURCE = "datasource"; + private static final GeneratorSchemaInfo SCHEMA_INFO = GeneratorBasicSchemas.SCHEMA_MAP.get("basic"); + private static final boolean USE_PARALLEL_MERGE_POOL_CONFIGURED = false; + + @Rule + public ExpectedException expectedException = ExpectedException.none(); + + private final ObjectMapper objectMapper = new DefaultObjectMapper(); + private final QueryToolChestWarehouse toolChestWarehouse; + private final QueryRunnerFactoryConglomerate conglomerate; + + private SegmentGenerator segmentGenerator; + private TestHttpClient httpClient; + private SimpleServerView simpleServerView; + private CachingClusteredClient cachingClusteredClient; + private List<DruidServer> servers; + + public RetryQueryRunnerTest() + { + conglomerate = QueryStackTests.createQueryRunnerFactoryConglomerate(CLOSER, USE_PARALLEL_MERGE_POOL_CONFIGURED); + + toolChestWarehouse = new QueryToolChestWarehouse() + { + @Override + public <T, QueryType extends Query<T>> QueryToolChest<T, QueryType> getToolChest(final QueryType query) + { + return conglomerate.findFactory(query).getToolchest(); + } + }; + } + + @AfterClass + public static void tearDownClass() throws IOException + { + CLOSER.close(); + } + + @Before + public void setup() + { + segmentGenerator = new SegmentGenerator(); + httpClient = new TestHttpClient(objectMapper); + simpleServerView = new SimpleServerView(toolChestWarehouse, objectMapper, httpClient); + cachingClusteredClient = new CachingClusteredClient( + toolChestWarehouse, + simpleServerView, + MapCache.create(0), + objectMapper, + new ForegroundCachePopulator(objectMapper, new CachePopulatorStats(), 0), + new CacheConfig(), + new DruidHttpClientConfig(), + QueryStackTests.getProcessingConfig(USE_PARALLEL_MERGE_POOL_CONFIGURED), + ForkJoinPool.commonPool(), + QueryStackTests.DEFAULT_NOOP_SCHEDULER + ); + servers = new ArrayList<>(); + } + + @After + public void tearDown() throws IOException + { + segmentGenerator.close(); + } + + private void addServer(DruidServer server, DataSegment dataSegment, QueryableIndex queryableIndex) + { + servers.add(server); + simpleServerView.addServer(server, dataSegment); + httpClient.addServerAndRunner(server, new SimpleServerManager(conglomerate, dataSegment.getId(), queryableIndex)); + } + + @Test + public void testNoRetry() + { + prepareCluster(10); + final TimeseriesQuery query = timeseriesQuery(SCHEMA_INFO.getDataInterval()); + final RetryQueryRunner<Result<TimeseriesResultValue>> queryRunner = createQueryRunner( + newRetryQueryRunnerConfig(1, false), + query + ); + final Sequence<Result<TimeseriesResultValue>> sequence = queryRunner.run(QueryPlus.wrap(query)); + final List<Result<TimeseriesResultValue>> queryResult = sequence.toList(); + Assert.assertEquals(0, queryRunner.getNumTotalRetries()); + Assert.assertFalse(queryResult.isEmpty()); + Assert.assertEquals(expectedTimeseriesResult(10), queryResult); + } + + @Test + public void testRetryForMovedSegment() + { + prepareCluster(10); + final TimeseriesQuery query = timeseriesQuery(SCHEMA_INFO.getDataInterval()); + final RetryQueryRunner<Result<TimeseriesResultValue>> queryRunner = createQueryRunner( + newRetryQueryRunnerConfig(1, true), + query + ); + final Sequence<Result<TimeseriesResultValue>> sequence = queryRunner.run(QueryPlus.wrap(query)); + + // Let's move a segment + dropSegmentFromServerAndAddNewServerForSegment(servers.get(0)); + + final List<Result<TimeseriesResultValue>> queryResult = sequence.toList(); + Assert.assertEquals(1, queryRunner.getNumTotalRetries()); Review comment: Before the last commit, `baseRunner.run()` was executed when `RetryQueryRunner.run()` is called. Since `baseRunner` is the query runner created by `CachingClusteredClient`, `RetryQueryRunner.run()` created the query distribution tree immediately. As a result, I could make the tests more deterministic by emulating moving segments between `sequence = RetryQueryRunner.run()` and `sequence.toList()`. In the last commit, I changed the code to defer calling `baseRunner.run()` until it has to get executed. This will minimize the chance of segments to move between the time to create query distribution tree and the time to actually send the query to servers. To keep the tests deterministic, I added a new constructor parameter, `runnableAfterFirstAttempt`, which is executed after creating query distribution true for the first attempt. This new parameter must be no-op in production code, but will be used only for testing. I think this parameter will be also useful for integration tests; I can add a new coordinator API to trigger segment balancing and call it after the first attempt using `runnableAfterFirstAttempt`. ########## File path: server/src/main/java/org/apache/druid/query/RetryQueryRunner.java ########## @@ -0,0 +1,204 @@ +/* + * 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.query; + +import com.fasterxml.jackson.core.type.TypeReference; +import com.fasterxml.jackson.databind.ObjectMapper; +import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.Preconditions; +import org.apache.druid.java.util.common.ISE; +import org.apache.druid.java.util.common.guava.BaseSequence; +import org.apache.druid.java.util.common.guava.BaseSequence.IteratorMaker; +import org.apache.druid.java.util.common.guava.MergeSequence; +import org.apache.druid.java.util.common.guava.Sequence; +import org.apache.druid.java.util.common.guava.Yielder; +import org.apache.druid.java.util.common.guava.YieldingAccumulator; +import org.apache.druid.java.util.common.guava.YieldingSequenceBase; +import org.apache.druid.java.util.common.logger.Logger; +import org.apache.druid.query.context.ResponseContext; +import org.apache.druid.query.context.ResponseContext.Key; +import org.apache.druid.segment.SegmentMissingException; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.Iterator; +import java.util.List; +import java.util.NoSuchElementException; +import java.util.function.BiFunction; + +public class RetryQueryRunner<T> implements QueryRunner<T> +{ + private static final Logger LOG = new Logger(RetryQueryRunner.class); + + private final QueryRunner<T> baseRunner; + private final BiFunction<Query<T>, List<SegmentDescriptor>, QueryRunner<T>> retryRunnerCreateFn; + private final RetryQueryRunnerConfig config; + private final ObjectMapper jsonMapper; + + private int numTotalRetries; + + public RetryQueryRunner( + QueryRunner<T> baseRunner, + BiFunction<Query<T>, List<SegmentDescriptor>, QueryRunner<T>> retryRunnerCreateFn, + RetryQueryRunnerConfig config, + ObjectMapper jsonMapper + ) + { + this.baseRunner = baseRunner; + this.retryRunnerCreateFn = retryRunnerCreateFn; + this.config = config; + this.jsonMapper = jsonMapper; + } + + @VisibleForTesting + int getNumTotalRetries() + { + return numTotalRetries; + } + + @Override + public Sequence<T> run(final QueryPlus<T> queryPlus, final ResponseContext context) + { + final Sequence<T> baseSequence = baseRunner.run(queryPlus, context); + return new YieldingSequenceBase<T>() + { + @Override + public <OutType> Yielder<OutType> toYielder(OutType initValue, YieldingAccumulator<OutType, T> accumulator) + { + final Sequence<Sequence<T>> retryingSequence = new BaseSequence<>( + new IteratorMaker<Sequence<T>, RetryingSequenceIterator>() + { + @Override + public RetryingSequenceIterator make() + { + return new RetryingSequenceIterator(queryPlus, context, baseSequence); + } + + @Override + public void cleanup(RetryingSequenceIterator iterFromMake) + { + numTotalRetries = iterFromMake.retryCount; + } + } + ); + return new MergeSequence<>(queryPlus.getQuery().getResultOrdering(), retryingSequence) + .toYielder(initValue, accumulator); + } + }; + } + + private List<SegmentDescriptor> getMissingSegments(final ResponseContext context) + { + // Sanity check before retrieving missingSegments from responseContext. + // The missingSegments in the responseContext is only valid when all servers have responded to the broker. + // The remainingResponses must be not null but 0 in the responseContext at this point. + final int remainingResponses = Preconditions.checkNotNull( + (Integer) context.get(Key.REMAINING_RESPONSES_FROM_QUERY_NODES), + "%s in responseContext", + Key.REMAINING_RESPONSES_FROM_QUERY_NODES.getName() + ); + if (remainingResponses > 0) { + throw new ISE("Failed to check missing segments due to missing responds from [%d] servers", remainingResponses); + } + + final Object maybeMissingSegments = context.get(ResponseContext.Key.MISSING_SEGMENTS); + if (maybeMissingSegments == null) { + return Collections.emptyList(); + } + + return jsonMapper.convertValue( + maybeMissingSegments, + new TypeReference<List<SegmentDescriptor>>() + { + } + ); + } + + /** + * A lazy iterator populating {@link Sequence} by retrying the query. The first returned sequence is always the base + * sequence given in the constructor. Subsequent sequences are created dynamically whenever it retries the query. All + * the sequences populated by this iterator will be merged (not combined) with the base sequence. + * + * The design of this iterator depends on how {@link MergeSequence} works; the MergeSequence pops an item from + * each underlying sequence and pushes them to a {@link java.util.PriorityQueue}. Whenever it pops from the queue, + * it pushes a new item from the sequence where the returned item was originally from. Since the first returned + * sequence from this iterator is always the base sequence, the MergeSequence will call {@link Sequence#toYielder} + * on the base sequence first which in turn initializing query distribution tree. Once this tree is built, the query + * nodes (historicals and realtime tasks) will lock all segments to read and report missing segments to the broker. + * If there are missing segments reported, this iterator will rewrite the query with those reported segments and + * reissue the rewritten query. + * + * @see org.apache.druid.client.CachingClusteredClient + * @see org.apache.druid.client.DirectDruidClient + */ + private class RetryingSequenceIterator implements Iterator<Sequence<T>> + { + private final QueryPlus<T> queryPlus; + private final ResponseContext context; + private Sequence<T> sequence; + private int retryCount = 0; + + private RetryingSequenceIterator(QueryPlus<T> queryPlus, ResponseContext context, Sequence<T> baseSequence) + { + this.queryPlus = queryPlus; + this.context = context; + this.sequence = baseSequence; + } + + @Override + public boolean hasNext() + { + if (sequence != null) { + return true; + } else { + final List<SegmentDescriptor> missingSegments = getMissingSegments(context); + if (missingSegments.isEmpty()) { + return false; + } else if (retryCount >= config.getNumTries()) { + if (!config.isReturnPartialResults()) { + throw new SegmentMissingException("No results found for segments[%s]", missingSegments); + } else { + return false; + } + } else { + LOG.info("[%,d] missing segments found. Retry attempt [%,d]", missingSegments.size(), retryCount++); Review comment: Oops, just copied it from the original code. Split incrementing count from the logging. ########## File path: server/src/main/java/org/apache/druid/query/RetryQueryRunner.java ########## @@ -0,0 +1,204 @@ +/* + * 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.query; + +import com.fasterxml.jackson.core.type.TypeReference; +import com.fasterxml.jackson.databind.ObjectMapper; +import com.google.common.annotations.VisibleForTesting; +import com.google.common.base.Preconditions; +import org.apache.druid.java.util.common.ISE; +import org.apache.druid.java.util.common.guava.BaseSequence; +import org.apache.druid.java.util.common.guava.BaseSequence.IteratorMaker; +import org.apache.druid.java.util.common.guava.MergeSequence; +import org.apache.druid.java.util.common.guava.Sequence; +import org.apache.druid.java.util.common.guava.Yielder; +import org.apache.druid.java.util.common.guava.YieldingAccumulator; +import org.apache.druid.java.util.common.guava.YieldingSequenceBase; +import org.apache.druid.java.util.common.logger.Logger; +import org.apache.druid.query.context.ResponseContext; +import org.apache.druid.query.context.ResponseContext.Key; +import org.apache.druid.segment.SegmentMissingException; + +import java.util.ArrayList; +import java.util.Collections; +import java.util.Iterator; +import java.util.List; +import java.util.NoSuchElementException; +import java.util.function.BiFunction; + +public class RetryQueryRunner<T> implements QueryRunner<T> +{ + private static final Logger LOG = new Logger(RetryQueryRunner.class); + + private final QueryRunner<T> baseRunner; + private final BiFunction<Query<T>, List<SegmentDescriptor>, QueryRunner<T>> retryRunnerCreateFn; + private final RetryQueryRunnerConfig config; + private final ObjectMapper jsonMapper; + + private int numTotalRetries; + + public RetryQueryRunner( + QueryRunner<T> baseRunner, + BiFunction<Query<T>, List<SegmentDescriptor>, QueryRunner<T>> retryRunnerCreateFn, + RetryQueryRunnerConfig config, + ObjectMapper jsonMapper + ) + { + this.baseRunner = baseRunner; + this.retryRunnerCreateFn = retryRunnerCreateFn; + this.config = config; + this.jsonMapper = jsonMapper; + } + + @VisibleForTesting + int getNumTotalRetries() Review comment: Renamed. ########## File path: server/src/test/java/org/apache/druid/query/RetryQueryRunnerTest.java ########## @@ -0,0 +1,326 @@ +/* + * 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.query; + +import com.fasterxml.jackson.databind.ObjectMapper; +import com.google.common.collect.ImmutableList; +import com.google.common.collect.ImmutableMap; +import org.apache.druid.client.CachingClusteredClient; +import org.apache.druid.client.DirectDruidClient; +import org.apache.druid.client.DruidServer; +import org.apache.druid.client.SimpleServerView; +import org.apache.druid.client.TestHttpClient; +import org.apache.druid.client.TestHttpClient.SimpleServerManager; +import org.apache.druid.client.cache.CacheConfig; +import org.apache.druid.client.cache.CachePopulatorStats; +import org.apache.druid.client.cache.ForegroundCachePopulator; +import org.apache.druid.client.cache.MapCache; +import org.apache.druid.guice.http.DruidHttpClientConfig; +import org.apache.druid.jackson.DefaultObjectMapper; +import org.apache.druid.java.util.common.DateTimes; +import org.apache.druid.java.util.common.Pair; +import org.apache.druid.java.util.common.granularity.Granularities; +import org.apache.druid.java.util.common.guava.Sequence; +import org.apache.druid.java.util.common.io.Closer; +import org.apache.druid.query.aggregation.CountAggregatorFactory; +import org.apache.druid.query.timeseries.TimeseriesQuery; +import org.apache.druid.query.timeseries.TimeseriesResultValue; +import org.apache.druid.segment.QueryableIndex; +import org.apache.druid.segment.SegmentMissingException; +import org.apache.druid.segment.generator.GeneratorBasicSchemas; +import org.apache.druid.segment.generator.GeneratorSchemaInfo; +import org.apache.druid.segment.generator.SegmentGenerator; +import org.apache.druid.server.QueryStackTests; +import org.apache.druid.timeline.DataSegment; +import org.apache.druid.timeline.SegmentId; +import org.apache.druid.timeline.partition.NumberedShardSpec; +import org.joda.time.Interval; +import org.junit.After; +import org.junit.AfterClass; +import org.junit.Assert; +import org.junit.Before; +import org.junit.Rule; +import org.junit.Test; +import org.junit.rules.ExpectedException; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.ForkJoinPool; +import java.util.stream.Collectors; +import java.util.stream.IntStream; + +public class RetryQueryRunnerTest +{ + private static final Closer CLOSER = Closer.create(); + private static final String DATASOURCE = "datasource"; + private static final GeneratorSchemaInfo SCHEMA_INFO = GeneratorBasicSchemas.SCHEMA_MAP.get("basic"); + private static final boolean USE_PARALLEL_MERGE_POOL_CONFIGURED = false; + + @Rule + public ExpectedException expectedException = ExpectedException.none(); + + private final ObjectMapper objectMapper = new DefaultObjectMapper(); + private final QueryToolChestWarehouse toolChestWarehouse; + private final QueryRunnerFactoryConglomerate conglomerate; + + private SegmentGenerator segmentGenerator; + private TestHttpClient httpClient; + private SimpleServerView simpleServerView; + private CachingClusteredClient cachingClusteredClient; + private List<DruidServer> servers; + + public RetryQueryRunnerTest() + { + conglomerate = QueryStackTests.createQueryRunnerFactoryConglomerate(CLOSER, USE_PARALLEL_MERGE_POOL_CONFIGURED); + + toolChestWarehouse = new QueryToolChestWarehouse() + { + @Override + public <T, QueryType extends Query<T>> QueryToolChest<T, QueryType> getToolChest(final QueryType query) + { + return conglomerate.findFactory(query).getToolchest(); + } + }; + } + + @AfterClass + public static void tearDownClass() throws IOException + { + CLOSER.close(); + } + + @Before + public void setup() + { + segmentGenerator = new SegmentGenerator(); + httpClient = new TestHttpClient(objectMapper); + simpleServerView = new SimpleServerView(toolChestWarehouse, objectMapper, httpClient); + cachingClusteredClient = new CachingClusteredClient( + toolChestWarehouse, + simpleServerView, + MapCache.create(0), + objectMapper, + new ForegroundCachePopulator(objectMapper, new CachePopulatorStats(), 0), + new CacheConfig(), + new DruidHttpClientConfig(), + QueryStackTests.getProcessingConfig(USE_PARALLEL_MERGE_POOL_CONFIGURED), + ForkJoinPool.commonPool(), + QueryStackTests.DEFAULT_NOOP_SCHEDULER + ); + servers = new ArrayList<>(); + } + + @After + public void tearDown() throws IOException + { + segmentGenerator.close(); + } + + private void addServer(DruidServer server, DataSegment dataSegment, QueryableIndex queryableIndex) + { + servers.add(server); + simpleServerView.addServer(server, dataSegment); + httpClient.addServerAndRunner(server, new SimpleServerManager(conglomerate, dataSegment.getId(), queryableIndex)); + } + + @Test + public void testNoRetry() + { + prepareCluster(10); + final TimeseriesQuery query = timeseriesQuery(SCHEMA_INFO.getDataInterval()); + final RetryQueryRunner<Result<TimeseriesResultValue>> queryRunner = createQueryRunner( + newRetryQueryRunnerConfig(1, false), + query + ); + final Sequence<Result<TimeseriesResultValue>> sequence = queryRunner.run(QueryPlus.wrap(query)); + final List<Result<TimeseriesResultValue>> queryResult = sequence.toList(); + Assert.assertEquals(0, queryRunner.getNumTotalRetries()); + Assert.assertFalse(queryResult.isEmpty()); + Assert.assertEquals(expectedTimeseriesResult(10), queryResult); + } + + @Test + public void testRetryForMovedSegment() + { + prepareCluster(10); + final TimeseriesQuery query = timeseriesQuery(SCHEMA_INFO.getDataInterval()); + final RetryQueryRunner<Result<TimeseriesResultValue>> queryRunner = createQueryRunner( + newRetryQueryRunnerConfig(1, true), + query + ); + final Sequence<Result<TimeseriesResultValue>> sequence = queryRunner.run(QueryPlus.wrap(query)); + + // Let's move a segment + dropSegmentFromServerAndAddNewServerForSegment(servers.get(0)); + + final List<Result<TimeseriesResultValue>> queryResult = sequence.toList(); + Assert.assertEquals(1, queryRunner.getNumTotalRetries()); + // Note that we dropped a segment from a server, but it's still announced in the server view. + // As a result, we may get the full result or not depending on what server will get the retry query. + // If we hit the same server, the query will return incomplete result. + Assert.assertTrue(queryResult.size() > 8); + Assert.assertEquals(expectedTimeseriesResult(queryResult.size()), queryResult); + } + + @Test + public void testRetryUntilWeGetFullResult() + { + prepareCluster(10); + final TimeseriesQuery query = timeseriesQuery(SCHEMA_INFO.getDataInterval()); + final RetryQueryRunner<Result<TimeseriesResultValue>> queryRunner = createQueryRunner( + newRetryQueryRunnerConfig(100, false), // retry up to 100 + query + ); + final Sequence<Result<TimeseriesResultValue>> sequence = queryRunner.run(QueryPlus.wrap(query)); + + // Let's move a segment + dropSegmentFromServerAndAddNewServerForSegment(servers.get(0)); + + final List<Result<TimeseriesResultValue>> queryResult = sequence.toList(); + Assert.assertTrue(0 < queryRunner.getNumTotalRetries()); + Assert.assertEquals(expectedTimeseriesResult(10), queryResult); + } + + @Test + public void testFailWithPartialResultsAfterRetry() + { + prepareCluster(10); + final TimeseriesQuery query = timeseriesQuery(SCHEMA_INFO.getDataInterval()); + final RetryQueryRunner<Result<TimeseriesResultValue>> queryRunner = createQueryRunner( + newRetryQueryRunnerConfig(1, false), + query + ); + final Sequence<Result<TimeseriesResultValue>> sequence = queryRunner.run(QueryPlus.wrap(query)); + dropSegmentFromServer(servers.get(0)); + + expectedException.expect(SegmentMissingException.class); + expectedException.expectMessage("No results found for segments"); + try { + sequence.toList(); + } + finally { + Assert.assertEquals(1, queryRunner.getNumTotalRetries()); + } + } + + private void prepareCluster(int numServers) + { + for (int i = 0; i < numServers; i++) { + final DataSegment segment = newSegment(SCHEMA_INFO.getDataInterval(), i); + addServer( + SimpleServerView.createServer(i + 1), + segment, + segmentGenerator.generate(segment, SCHEMA_INFO, Granularities.NONE, 10) + ); + } + } + + private Pair<SegmentId, QueryableIndex> dropSegmentFromServer(DruidServer fromServer) Review comment: Added for both methods. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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