vtlim commented on code in PR #12569: URL: https://github.com/apache/druid/pull/12569#discussion_r891547217
########## docs/ingestion/automatic-compaction.md: ########## @@ -0,0 +1,198 @@ +--- +id: automatic-compaction +title: "Automatic compaction" +--- + +<!-- + ~ 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. + --> + +In Apache Druid, compaction is a special type of ingestion task that reads data from a Druid datasource and writes it back into the same datasource. A common use case for this is to [optimally size segments](../operations/segment-optimization.md) after ingestion to improve query performance. Automatic compaction, or auto-compaction, refers to the system for automatic execution of compaction tasks managed by the [Druid Coordinator](../design/coordinator.md). + +The Coordinator [indexing period](../configuration/index.md#coordinator-operation), `druid.coordinator.period.indexingPeriod`, controls the frequency of compaction tasks. +The default indexing period is 30 minutes, meaning that the Coordinator first checks for segments to compact at most 30 minutes from when auto-compaction is enabled. +This time period affects other Coordinator duties including merge and conversion tasks. +To configure the auto-compaction time period, see [Set frequency of compaction runs](#set-frequency-of-compaction-runs). + +At every indexing period, the Coordinator initiates a [segment search](../design/coordinator.md#segment-search-policy-in-automatic-compaction) to determine eligible segments to compact. Review Comment: Good suggestion! -- 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]
