weizhengte commented on code in PR #8859: URL: https://github.com/apache/incubator-doris/pull/8859#discussion_r857140673
########## fe/fe-core/src/main/java/org/apache/doris/statistics/StatisticsJobScheduler.java: ########## @@ -18,46 +18,246 @@ package org.apache.doris.statistics; import org.apache.doris.catalog.Catalog; +import org.apache.doris.catalog.Column; +import org.apache.doris.catalog.Database; +import org.apache.doris.catalog.KeysType; +import org.apache.doris.catalog.OlapTable; +import org.apache.doris.catalog.Table; +import org.apache.doris.catalog.Type; +import org.apache.doris.common.Config; +import org.apache.doris.common.DdlException; import org.apache.doris.common.util.MasterDaemon; import com.google.common.collect.Queues; -import java.util.ArrayList; +import org.apache.logging.log4j.LogManager; +import org.apache.logging.log4j.Logger; + +import java.util.Arrays; +import java.util.Collections; import java.util.List; +import java.util.Map; import java.util.Queue; +import java.util.Set; -/* -Schedule statistics job. - 1. divide job to multi task - 2. submit all task to StatisticsTaskScheduler -Switch job state from pending to scheduling. +/** + * Schedule statistics job. + * 1. divide job to multi task + * 2. submit all task to StatisticsTaskScheduler + * Switch job state from pending to scheduling. */ public class StatisticsJobScheduler extends MasterDaemon { + private static final Logger LOG = LogManager.getLogger(StatisticsJobScheduler.class); + + /** + * If the table row-count is greater than the maximum number of Be scans for a single BE, + * we'll divide subtasks by partition. relevant values(3700000000L&600000000L) are derived from test. + * COUNT_MAX_SCAN_PER_TASK is for count(expr), NDV_MAX_SCAN_PER_TASK is for min(c1)/max(c1)/ndv(c1). + */ + private static final long COUNT_MAX_SCAN_PER_TASK = 3700000000L; + private static final long NDV_MAX_SCAN_PER_TASK = 600000000L; - public Queue<StatisticsJob> pendingJobQueue = Queues.newLinkedBlockingQueue(); + /** + * Different statistics need to be collected for the jobs submitted by users. + * if all statistics be collected at the same time, the cluster may be overburdened + * and normal query services may be affected. Therefore, we put the jobs into the queue + * and schedule them one by one, and finally divide each job to several subtasks and execute them. + */ + public final Queue<StatisticsJob> pendingJobQueue = Queues.newLinkedBlockingQueue(Config.cbo_max_statistics_job_num); public StatisticsJobScheduler() { super("Statistics job scheduler", 0); } @Override protected void runAfterCatalogReady() { - // TODO StatisticsJob pendingJob = pendingJobQueue.peek(); - // step0: check job state again - // step1: divide statistics job to task - List<StatisticsTask> statisticsTaskList = divide(pendingJob); - // step2: submit - Catalog.getCurrentCatalog().getStatisticsTaskScheduler().addTasks(statisticsTaskList); + if (pendingJob != null) { + try { + if (pendingJob.getTasks().size() == 0) { + divide(pendingJob); + } + List<StatisticsTask> tasks = pendingJob.getTasks(); + Catalog.getCurrentCatalog().getStatisticsTaskScheduler().addTasks(tasks); + pendingJob.updateJobState(StatisticsJob.JobState.SCHEDULING); + pendingJobQueue.remove(); + } catch (IllegalStateException e) { + // throw IllegalStateException if the queue is full, re-add the tasks next time + LOG.info("The statistics task queue is full, schedule the job(id={}) later", pendingJob.getId()); + } catch (DdlException e) { + pendingJobQueue.remove(); + pendingJob.updateJobState(StatisticsJob.JobState.FAILED); + LOG.info("Failed to schedule the statistical job(id={})", pendingJob.getId(), e); + } + } } public void addPendingJob(StatisticsJob statisticsJob) throws IllegalStateException { pendingJobQueue.add(statisticsJob); } + /** + * Statistics tasks are of the following types: + * table: + * - row_count: table row count are critical in estimating cardinality and memory usage of scan nodes. + * - data_size: table size, not applicable to CBO, mainly used to monitor and manage table size. + * column: + * - num_distinct_value: used to determine the selectivity of an equivalent expression. + * - min: The minimum value. + * - max: The maximum value. + * - num_nulls: number of nulls. + * - avg_col_len: the average length of a column, in bytes, is used for memory and network IO evaluation. + * - max_col_len: the Max length of the column, in bytes, is used for memory and network IO evaluation. + * <p> + * Divide: + * - min, max, ndv: These three full indicators are collected by a sub-task. + * - max_col_lens, avg_col_lens: Two sampling indicators were collected by a sub-task. + * <p> + * If the table row-count is greater than the maximum number of Be scans for a single BE, + * we'll divide subtasks by partition. relevant values(3700000000L&600000000L) are derived from test. + * <p> + * Eventually, we will get several subtasks of the following types: + * + * @throws DdlException DdlException + * @see MetaStatisticsTask + * @see SampleSQLStatisticsTask + * @see SQLStatisticsTask + */ + private void divide(StatisticsJob statisticsJob) throws DdlException { + long jobId = statisticsJob.getId(); + long dbId = statisticsJob.getDbId(); + Database db = Catalog.getCurrentCatalog().getDbOrDdlException(dbId); + Set<Long> tblIds = statisticsJob.getTblIds(); + Map<Long, List<String>> tableIdToColumnName = statisticsJob.getTableIdToColumnName(); + List<StatisticsTask> tasks = statisticsJob.getTasks(); + List<Long> backendIds = Catalog.getCurrentSystemInfo().getBackendIds(true); + + for (Long tblId : tblIds) { + Table tbl = db.getTableOrDdlException(tblId); + long rowCount = tbl.getRowCount(); + List<Long> partitionIds = ((OlapTable) tbl).getPartitionIds(); + List<String> columnNameList = tableIdToColumnName.get(tblId); + + // step 1: generate data_size task + StatsCategoryDesc dataSizeCategory = getTblStatsCategoryDesc(dbId, tblId); + StatsGranularityDesc dataSizeGranularity = getTblStatsGranularityDesc(tblId); + MetaStatisticsTask dataSizeTask = new MetaStatisticsTask(jobId, + dataSizeGranularity, dataSizeCategory, Collections.singletonList(StatsType.DATA_SIZE)); + tasks.add(dataSizeTask); + + // step 2: generate row_count task + KeysType keysType = ((OlapTable) tbl).getKeysType(); + if (keysType == KeysType.DUP_KEYS) { + StatsCategoryDesc rowCountCategory = getTblStatsCategoryDesc(dbId, tblId); + StatsGranularityDesc rowCountGranularity = getTblStatsGranularityDesc(tblId); + MetaStatisticsTask metaTask = new MetaStatisticsTask(jobId, + rowCountGranularity, rowCountCategory, Collections.singletonList(StatsType.ROW_COUNT)); + tasks.add(metaTask); + } else { + if (rowCount > backendIds.size() * COUNT_MAX_SCAN_PER_TASK) { + // divide subtasks by partition + for (Long partitionId : partitionIds) { + StatsCategoryDesc rowCountCategory = getTblStatsCategoryDesc(dbId, tblId); + StatsGranularityDesc rowCountGranularity = getPartitionStatsGranularityDesc(tblId, partitionId); + SQLStatisticsTask sqlTask = new SQLStatisticsTask(jobId, + rowCountGranularity, rowCountCategory, Collections.singletonList(StatsType.ROW_COUNT)); + tasks.add(sqlTask); + } + } else { + StatsCategoryDesc rowCountCategory = getTblStatsCategoryDesc(dbId, tblId); + StatsGranularityDesc rowCountGranularity = getTblStatsGranularityDesc(tblId); + SQLStatisticsTask sqlTask = new SQLStatisticsTask(jobId, + rowCountGranularity, rowCountCategory, Collections.singletonList(StatsType.ROW_COUNT)); + tasks.add(sqlTask); + } + } + + // step 3: generate [min,max,ndv] task + if (rowCount > backendIds.size() * NDV_MAX_SCAN_PER_TASK) { + for (String columnName : columnNameList) { Review Comment: That's true -- This is an automated message from the Apache Git Service. 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