JingsongLi commented on a change in pull request #12004: URL: https://github.com/apache/flink/pull/12004#discussion_r422454432
########## File path: flink-connectors/flink-connector-hive/src/main/java/org/apache/flink/connectors/hive/read/HiveContinuousMonitoringFunction.java ########## @@ -0,0 +1,280 @@ +/* + * 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.flink.connectors.hive.read; + +import org.apache.flink.api.common.state.ListState; +import org.apache.flink.api.common.state.ListStateDescriptor; +import org.apache.flink.api.common.typeutils.base.ListSerializer; +import org.apache.flink.api.common.typeutils.base.LongSerializer; +import org.apache.flink.api.common.typeutils.base.StringSerializer; +import org.apache.flink.connectors.hive.HiveTablePartition; +import org.apache.flink.connectors.hive.HiveTableSource; +import org.apache.flink.connectors.hive.JobConfWrapper; +import org.apache.flink.connectors.hive.read.PartitionStrategy.PartitionStrategyFactory; +import org.apache.flink.runtime.state.FunctionInitializationContext; +import org.apache.flink.runtime.state.FunctionSnapshotContext; +import org.apache.flink.streaming.api.checkpoint.CheckpointedFunction; +import org.apache.flink.streaming.api.functions.source.ContinuousFileReaderOperator; +import org.apache.flink.streaming.api.functions.source.RichSourceFunction; +import org.apache.flink.table.catalog.CatalogTable; +import org.apache.flink.table.catalog.ObjectPath; +import org.apache.flink.table.catalog.hive.client.HiveShim; +import org.apache.flink.table.catalog.hive.util.HiveReflectionUtils; +import org.apache.flink.table.types.DataType; +import org.apache.flink.util.Preconditions; + +import org.apache.hadoop.hive.conf.HiveConf; +import org.apache.hadoop.hive.metastore.IMetaStoreClient; +import org.apache.hadoop.hive.metastore.api.Partition; +import org.apache.hadoop.hive.metastore.api.Table; +import org.apache.hadoop.mapred.JobConf; +import org.apache.thrift.TException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashSet; +import java.util.List; +import java.util.Properties; +import java.util.Set; + +/** + * This is the single (non-parallel) monitoring task which takes a {@link HiveTableInputFormat}, + * it is responsible for: + * + * <ol> + * <li>Monitoring partitions of hive meta store.</li> + * <li>Deciding which partitions should be further read and processed.</li> + * <li>Creating the {@link HiveTableInputSplit splits} corresponding to those partitions.</li> + * <li>Assigning them to downstream tasks for further processing.</li> + * </ol> + * + * <p>The splits to be read are forwarded to the downstream {@link ContinuousFileReaderOperator} + * which can have parallelism greater than one. + * + * <p><b>IMPORTANT NOTE: </b> Splits are forwarded downstream for reading in ascending partition time order, + * based on the partition time of the partitions they belong to. + */ +public class HiveContinuousMonitoringFunction + extends RichSourceFunction<TimestampedHiveInputSplit> + implements CheckpointedFunction { + + private static final long serialVersionUID = 1L; + + private static final Logger LOG = LoggerFactory.getLogger(HiveContinuousMonitoringFunction.class); + + /** The parallelism of the downstream readers. */ + private final int readerParallelism; + + /** The interval between consecutive path scans. */ + private final long interval; + + private final HiveShim hiveShim; + + private final JobConfWrapper conf; + + private final ObjectPath tablePath; + + private final List<String> partitionKeys; + + private final String[] fieldNames; + + private final DataType[] fieldTypes; + + private final long startupTimestampMillis; + + private final PartitionStrategyFactory partStrategyFactory; + + private volatile boolean isRunning = true; + + /** The maximum partition read time seen so far. */ + private volatile long currentReadTime; + + private transient PartitionStrategy strategy; + + private transient Object checkpointLock; + + private transient ListState<Long> currReadTimeState; + + private transient ListState<List<List<String>>> distinctPartsState; + + private transient IMetaStoreClient client; + + private transient Properties tableProps; + + private transient String defaultPartitionName; + + private transient Set<List<String>> distinctPartitions; + + public HiveContinuousMonitoringFunction( + HiveShim hiveShim, + JobConf conf, + ObjectPath tablePath, + CatalogTable catalogTable, + long startupTimestampMillis, + PartitionStrategyFactory partStrategyFactory, + int readerParallelism, + long interval) { + this.hiveShim = hiveShim; + this.conf = new JobConfWrapper(conf); + this.tablePath = tablePath; + this.partitionKeys = catalogTable.getPartitionKeys(); + this.fieldNames = catalogTable.getSchema().getFieldNames(); + this.fieldTypes = catalogTable.getSchema().getFieldDataTypes(); + this.startupTimestampMillis = startupTimestampMillis; + this.partStrategyFactory = partStrategyFactory; + + this.interval = interval; + this.readerParallelism = Math.max(readerParallelism, 1); + this.currentReadTime = Long.MIN_VALUE; + } + + @Override + public void initializeState(FunctionInitializationContext context) throws Exception { + this.strategy = partStrategyFactory.createStrategy(getRuntimeContext().getUserCodeClassLoader()); + + this.currReadTimeState = context.getOperatorStateStore().getListState( + new ListStateDescriptor<>( + "partition-monitoring-state", + LongSerializer.INSTANCE + ) + ); + this.distinctPartsState = context.getOperatorStateStore().getListState( + new ListStateDescriptor<>( + "partition-monitoring-state", + new ListSerializer<>(new ListSerializer<>(StringSerializer.INSTANCE)) + ) + ); + + this.client = this.hiveShim.getHiveMetastoreClient(new HiveConf(conf.conf(), HiveConf.class)); + + Table hiveTable = client.getTable(tablePath.getDatabaseName(), tablePath.getObjectName()); + this.tableProps = HiveReflectionUtils.getTableMetadata(hiveShim, hiveTable); + this.defaultPartitionName = conf.conf().get(HiveConf.ConfVars.DEFAULTPARTITIONNAME.varname, + HiveConf.ConfVars.DEFAULTPARTITIONNAME.defaultStrVal); + + this.distinctPartitions = new HashSet<>(); + if (context.isRestored()) { + LOG.info("Restoring state for the {}.", getClass().getSimpleName()); + this.currentReadTime = this.currReadTimeState.get().iterator().next(); + this.distinctPartitions.addAll(this.distinctPartsState.get().iterator().next()); + } else { + LOG.info("No state to restore for the {}.", getClass().getSimpleName()); + this.currentReadTime = this.startupTimestampMillis; + } + } + + @Override + public void run(SourceContext<TimestampedHiveInputSplit> context) throws Exception { + checkpointLock = context.getCheckpointLock(); + while (isRunning) { + synchronized (checkpointLock) { + monitorAndForwardSplits(context); + } + Thread.sleep(interval); + } + } + + private void monitorAndForwardSplits( + SourceContext<TimestampedHiveInputSplit> context) throws IOException, TException { + assert (Thread.holdsLock(checkpointLock)); + + List<Partition> partitions = client.listPartitionsByFilter( + tablePath.getDatabaseName(), + tablePath.getObjectName(), + strategy.generateFetchFilter(partitionKeys, currentReadTime), + (short) -1); + + if (partitions.isEmpty()) { + return; + } + + long maxTime = Long.MIN_VALUE; + for (Partition partition : partitions) { + List<String> partSpec = partition.getValues(); + if (!this.distinctPartitions.contains(partSpec)) { + this.distinctPartitions.add(partition.getValues()); + long time = this.strategy.extractPartTime(partitionKeys, partition.getValues()); + if (time > maxTime) { + maxTime = time; + } + HiveTableInputSplit[] splits = HiveTableInputFormat.createInputSplits( + this.readerParallelism, + Collections.singletonList(toHiveTablePartition(partition)), + this.conf.conf()); + for (HiveTableInputSplit split : splits) { + context.collect(new TimestampedHiveInputSplit(time, split)); + } + } + } + this.currentReadTime = maxTime; + + this.distinctPartitions.removeIf(partSpec -> this.strategy.canExpireForDistinct( + this.strategy.extractPartTime(partitionKeys, partSpec), + this.currentReadTime)); + } + + private HiveTablePartition toHiveTablePartition(Partition p) { + return HiveTableSource.toHiveTablePartition( + partitionKeys, fieldNames, fieldTypes, hiveShim, tableProps, defaultPartitionName, p); + } + + @Override + public void snapshotState(FunctionSnapshotContext context) throws Exception { + Preconditions.checkState(this.currReadTimeState != null, + "The " + getClass().getSimpleName() + " state has not been properly initialized."); + + this.currReadTimeState.clear(); + this.currReadTimeState.add(this.currentReadTime); + + this.distinctPartsState.clear(); + this.distinctPartsState.add(new ArrayList<>(this.distinctPartitions)); + + if (LOG.isDebugEnabled()) { + LOG.debug("{} checkpointed {}.", getClass().getSimpleName(), currentReadTime); + } + } + + @Override + public void close() throws Exception { + super.close(); + + if (checkpointLock != null) { + synchronized (checkpointLock) { + currentReadTime = Long.MAX_VALUE; + isRunning = false; + } + } + } + + @Override + public void cancel() { + if (checkpointLock != null) { + // this is to cover the case where cancel() is called before the run() Review comment: this is from another thread. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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