DanielZhu58 commented on code in PR #6438: URL: https://github.com/apache/hive/pull/6438#discussion_r3217268398
########## standalone-metastore/metastore-server/src/main/java/org/apache/hadoop/hive/metastore/StatisticsManagementTask.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.hadoop.hive.metastore; + +import java.util.List; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.locks.Lock; +import java.util.concurrent.locks.ReentrantLock; + +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.hive.metastore.api.DeleteColumnStatisticsRequest; +import org.apache.hadoop.hive.metastore.conf.MetastoreConf; +import org.apache.hadoop.hive.metastore.model.MPartitionColumnStatistics; +import org.apache.hadoop.hive.metastore.model.MTableColumnStatistics; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import javax.jdo.PersistenceManager; +import javax.jdo.Query; + +/** + * Statistics management task responsible for periodic auto-deletion of table and partition column + * statistics based on a configured retention interval. + * + * <p>When {@code metastore.statistics.auto.deletion} is enabled, this task scans + * {@code TAB_COL_STATS} and {@code PART_COL_STATS} for rows whose {@code lastAnalyzed} timestamp + * is older than {@code metastore.statistics.retention.period}, and deletes them. + * Individual tables may opt out by setting the table property + * {@value #STATISTICS_AUTO_DELETION_EXCLUDE_TBLPROPERTY} to any non-null value. + */ +public class StatisticsManagementTask extends ObjectStore implements MetastoreTaskThread { + + private static final Logger LOG = LoggerFactory.getLogger(StatisticsManagementTask.class); + + /** + * Table property key that, when present on a table, excludes it from automatic statistics + * deletion regardless of the global retention setting. + */ + public static final String STATISTICS_AUTO_DELETION_EXCLUDE_TBLPROPERTY = + "statistics.auto.deletion.exclude"; + + private static final Lock LOCK = new ReentrantLock(); + + private Configuration conf; + + @Override + public long runFrequency(TimeUnit unit) { + return MetastoreConf.getTimeVar(conf, MetastoreConf.ConfVars.COLUMN_STATISTICS_MANAGEMENT_TASK_FREQUENCY, unit); + } + + @Override + public void setConf(Configuration configuration) { + this.conf = new Configuration(configuration); + super.setConf(configuration); + } + + @Override + public Configuration getConf() { + return conf; + } + + @Override + public void run() { + LOG.debug("Auto statistics deletion started. Cleaning up table/partition column statistics over the retention period."); + long retentionMillis = + MetastoreConf.getTimeVar(conf, MetastoreConf.ConfVars.COLUMN_STATISTICS_RETENTION_PERIOD, TimeUnit.MILLISECONDS); + if (retentionMillis <= 0 || !MetastoreConf.getBoolVar(conf, MetastoreConf.ConfVars.COLUMN_STATISTICS_AUTO_DELETION)) { + LOG.info("Statistics auto deletion is set to off currently."); + return; + } + if (!LOCK.tryLock()) { + return; + } + try { + long now = System.currentTimeMillis(); + long lastAnalyzedThreshold = (now - retentionMillis) / 1000; + PersistenceManager pm = getPersistenceManager(); + boolean committed = false; + openTransaction(); + try { + try (IMetaStoreClient msc = new HiveMetaStoreClient(conf)) { + deleteExpiredTableColStats(pm, msc, lastAnalyzedThreshold); + deleteExpiredPartitionColStats(pm, msc, lastAnalyzedThreshold); + } + committed = commitTransaction(); + } finally { + if (!committed) { + rollbackTransaction(); + } + } + } catch (Exception e) { + LOG.error("Error during statistics auto deletion", e); + } finally { + LOCK.unlock(); + } + } + + /** + * Deletes expired table-level column statistics from {@code TAB_COL_STATS}. + * Tables with the {@value #STATISTICS_AUTO_DELETION_EXCLUDE_TBLPROPERTY} property set are skipped. + * + * @param pm the JDO persistence manager to use for the query + * @param msc the metastore client used to issue delete requests + * @param lastAnalyzedThreshold epoch seconds; rows with lastAnalyzed below this value are expired + * @throws Exception if the JDO query or the delete request fails + */ + private void deleteExpiredTableColStats(PersistenceManager pm, IMetaStoreClient msc, + long lastAnalyzedThreshold) throws Exception { + Query tblQuery = null; + try { + tblQuery = pm.newQuery(MTableColumnStatistics.class); + tblQuery.setFilter("lastAnalyzed < threshold"); + tblQuery.declareParameters("long threshold"); + // partitionName does not exist on MTableColumnStatistics; omitted here + tblQuery.setResult( + "table.database.name, " + + "table.tableName, " + + "table.parameters.get(\"" + STATISTICS_AUTO_DELETION_EXCLUDE_TBLPROPERTY + "\")"); + @SuppressWarnings("unchecked") + List<Object[]> tblRows = (List<Object[]>) tblQuery.execute(lastAnalyzedThreshold); + for (Object[] row : tblRows) { + String dbName = (String) row[0]; + String tblName = (String) row[1]; + String excludeVal = (String) row[2]; + if (excludeVal != null) { + LOG.info("Skipping auto deletion of table stats for {}.{} due to exclude property.", + dbName, tblName); + continue; + } + DeleteColumnStatisticsRequest request = new DeleteColumnStatisticsRequest(dbName, tblName); + request.setEngine("hive"); + request.setTableLevel(true); + msc.deleteColumnStatistics(request); Review Comment: Acknowledged. I changed the implementation, we no longer use the request. And also use the specific column name every time to make sure we do not delete all the column stats. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
