com.hazelcast.map.impl.query.QueryRunner Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2018, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.map.impl.query;
import com.hazelcast.internal.cluster.ClusterService;
import com.hazelcast.internal.serialization.InternalSerializationService;
import com.hazelcast.logging.ILogger;
import com.hazelcast.map.impl.LocalMapStatsProvider;
import com.hazelcast.map.impl.MapContainer;
import com.hazelcast.map.impl.MapServiceContext;
import com.hazelcast.monitor.impl.LocalMapStatsImpl;
import com.hazelcast.query.Predicate;
import com.hazelcast.query.impl.Indexes;
import com.hazelcast.query.impl.QueryableEntriesSegment;
import com.hazelcast.query.impl.QueryableEntry;
import com.hazelcast.query.impl.predicates.QueryOptimizer;
import com.hazelcast.spi.NodeEngine;
import com.hazelcast.spi.OperationService;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
/**
* Runs query operations in the calling thread (thus blocking it)
*
* Used by query operations only: QueryOperation & QueryPartitionOperation
* Should not be used by proxies or any other query related objects.
*/
public class QueryRunner {
protected final MapServiceContext mapServiceContext;
protected final NodeEngine nodeEngine;
protected final ILogger logger;
protected final QueryResultSizeLimiter queryResultSizeLimiter;
protected final InternalSerializationService serializationService;
protected final QueryOptimizer queryOptimizer;
protected final OperationService operationService;
protected final ClusterService clusterService;
protected final LocalMapStatsProvider localMapStatsProvider;
protected final PartitionScanExecutor partitionScanExecutor;
protected final ResultProcessorRegistry resultProcessorRegistry;
public QueryRunner(MapServiceContext mapServiceContext, QueryOptimizer optimizer, PartitionScanExecutor partitionScanExecutor,
ResultProcessorRegistry resultProcessorRegistry) {
this.mapServiceContext = mapServiceContext;
this.nodeEngine = mapServiceContext.getNodeEngine();
this.serializationService = (InternalSerializationService) nodeEngine.getSerializationService();
this.logger = nodeEngine.getLogger(getClass());
this.queryResultSizeLimiter = new QueryResultSizeLimiter(mapServiceContext, logger);
this.queryOptimizer = optimizer;
this.operationService = nodeEngine.getOperationService();
this.clusterService = nodeEngine.getClusterService();
this.localMapStatsProvider = mapServiceContext.getLocalMapStatsProvider();
this.partitionScanExecutor = partitionScanExecutor;
this.resultProcessorRegistry = resultProcessorRegistry;
}
/**
* Runs a query on a chunk of a single partition. The chunk is defined by the offset {@code tableIndex}
* and the soft limit {@code fetchSize}.
*
* @param query the query
* @param partitionId the partition which is queried
* @param tableIndex the index at which to start querying
* @param fetchSize the soft limit for the number of items to be queried
* @return the queried entries along with the next {@code tableIndex} to resume querying
*/
public ResultSegment runPartitionScanQueryOnPartitionChunk(Query query, int partitionId, int tableIndex, int fetchSize) {
final MapContainer mapContainer = mapServiceContext.getMapContainer(query.getMapName());
final Predicate predicate = queryOptimizer.optimize(query.getPredicate(), mapContainer.getIndexes());
final QueryableEntriesSegment entries = partitionScanExecutor
.execute(query.getMapName(), predicate, partitionId, tableIndex, fetchSize);
updateStatistics(mapContainer);
final ResultProcessor processor = resultProcessorRegistry.get(query.getResultType());
final Result result = processor
.populateResult(query, Long.MAX_VALUE, entries.getEntries(), Collections.singletonList(partitionId));
return new ResultSegment(result, entries.getNextTableIndexToReadFrom());
}
// MIGRATION SAFE QUERYING -> MIGRATION STAMPS ARE VALIDATED (does not have to run on a partition thread)
// full query = index query (if possible), then partition-scan query
public Result runIndexOrPartitionScanQueryOnOwnedPartitions(Query query) {
int migrationStamp = getMigrationStamp();
Collection initialPartitions = mapServiceContext.getOwnedPartitions();
MapContainer mapContainer = mapServiceContext.getMapContainer(query.getMapName());
// to optimize the query we need to get any index instance
Indexes indexes = mapContainer.getIndexes();
if (indexes == null) {
indexes = mapContainer.getIndexes(initialPartitions.iterator().next());
}
// first we optimize the query
Predicate predicate = queryOptimizer.optimize(query.getPredicate(), indexes);
// then we try to run using an index, but if that doesn't work, we'll try a full table scan
Collection entries = runUsingGlobalIndexSafely(predicate, mapContainer, migrationStamp);
Result result;
if (entries == null) {
result = runUsingPartitionScanSafely(query, predicate, initialPartitions, migrationStamp);
} else {
result = populateResult(query, initialPartitions, entries);
}
updateStatistics(mapContainer);
return result;
}
// MIGRATION UNSAFE QUERYING - MIGRATION STAMPS ARE NOT VALIDATED, so assumes a run on partition-thread
// for a single partition. If the index is global it won't be asked
public Result runPartitionIndexOrPartitionScanQueryOnGivenOwnedPartition(Query query, int partitionId) {
MapContainer mapContainer = mapServiceContext.getMapContainer(query.getMapName());
List partitions = Collections.singletonList(partitionId);
// first we optimize the query
Predicate predicate = queryOptimizer.optimize(query.getPredicate(), mapContainer.getIndexes(partitionId));
Collection entries = null;
Indexes indexes = mapContainer.getIndexes(partitionId);
if (indexes != null && !indexes.isGlobal()) {
entries = indexes.query(predicate);
}
Result result;
if (entries == null) {
result = createResult(query, partitions);
partitionScanExecutor.execute(query.getMapName(), predicate, partitions, result);
result.completeConstruction(partitions);
} else {
result = populateResult(query, partitions, entries);
}
updateStatistics(mapContainer);
return result;
}
private Result populateResult(Query query, Collection partitions, Collection entries) {
if (entries != null) {
// if results have been returned and partition state has not changed, set the partition IDs
// so that caller is aware of partitions from which results were obtained.
return populateNonEmptyResult(query, entries, partitions);
} else {
// else: if fallback to full table scan also failed to return any results due to migrations,
// then return empty result set without any partition IDs set (so that it is ignored by callers).
return populateEmptyResult(query, partitions);
}
}
Result runPartitionScanQueryOnGivenOwnedPartition(Query query, int partitionId) {
MapContainer mapContainer = mapServiceContext.getMapContainer(query.getMapName());
Predicate predicate = queryOptimizer.optimize(query.getPredicate(), mapContainer.getIndexes(partitionId));
Collection partitions = Collections.singletonList(partitionId);
Result result = createResult(query, partitions);
partitionScanExecutor.execute(query.getMapName(), predicate, partitions, result);
result.completeConstruction(partitions);
return result;
}
private Result createResult(Query query, Collection partitions) {
return query.createResult(serializationService, queryResultSizeLimiter.getNodeResultLimit(partitions.size()));
}
protected Result populateEmptyResult(Query query, Collection initialPartitions) {
return resultProcessorRegistry.get(query.getResultType())
.populateResult(query, queryResultSizeLimiter.getNodeResultLimit(initialPartitions.size()));
}
protected Result populateNonEmptyResult(Query query, Collection entries,
Collection initialPartitions) {
ResultProcessor processor = resultProcessorRegistry.get(query.getResultType());
return processor.populateResult(query, queryResultSizeLimiter.getNodeResultLimit(initialPartitions.size()), entries,
initialPartitions);
}
protected Collection runUsingGlobalIndexSafely(Predicate predicate, MapContainer mapContainer,
int migrationStamp) {
// If a migration is in progress or migration ownership changes,
// do not attempt to use an index as they may have not been created yet.
if (!validateMigrationStamp(migrationStamp)) {
return null;
}
Indexes indexes = mapContainer.getIndexes();
if (indexes == null) {
return null;
}
if (!indexes.isGlobal()) {
// rolling-upgrade compatibility guide, if the index is not global we can't use it in the global scan.
// it may happen if the 3.9 EE node receives a QueryOperation from a 3.8 node, in this case we can't
// leverage index on this node in a global way.
return null;
}
Collection entries = indexes.query(predicate);
if (entries == null) {
return null;
}
// If a migration is in progress or migration ownership changes,
// do not attempt to use an index as they may have not been created yet.
// This means migrations were executed and we may
// return stale data, so we should rather return null and let the query run with a full table scan.
// Also make sure there are no long migrations in flight which may have started after starting the query
// but not completed yet.
if (validateMigrationStamp(migrationStamp)) {
return entries;
}
return null;
}
protected Result runUsingPartitionScanSafely(Query query, Predicate predicate, Collection partitions,
int migrationStamp) {
if (!validateMigrationStamp(migrationStamp)) {
return null;
}
Result result = createResult(query, partitions);
partitionScanExecutor.execute(query.getMapName(), predicate, partitions, result);
// If a migration is in progress or migration ownership changes, this means migrations were executed and we may
// return stale data, so we should rather return null.
// Also make sure there are no long migrations in flight which may have started after starting the query
// but not completed yet.
if (validateMigrationStamp(migrationStamp)) {
result.completeConstruction(partitions);
return result;
}
return createResult(query, partitions);
}
private int getMigrationStamp() {
return mapServiceContext.getService().getMigrationStamp();
}
private boolean validateMigrationStamp(int migrationStamp) {
return mapServiceContext.getService().validateMigrationStamp(migrationStamp);
}
private void updateStatistics(MapContainer mapContainer) {
if (mapContainer.getMapConfig().isStatisticsEnabled()) {
LocalMapStatsImpl localStats = localMapStatsProvider.getLocalMapStatsImpl(mapContainer.getName());
localStats.incrementOtherOperations();
}
}
}