tillrohrmann commented on a change in pull request #10999: [FLINK-15143] Docs for FLIP-49 TM memory model and configuration guide URL: https://github.com/apache/flink/pull/10999#discussion_r376654386
########## File path: docs/ops/memory/mem_detail.md ########## @@ -0,0 +1,149 @@ +--- +title: "Detailed Memory Model" +nav-parent_id: ops_mem +nav-pos: 2 +--- +<!-- +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. +--> + +This section gives a detailed description of all components in Flink’s memory model of task executor. +Check [memory configuration guide](mem_setup.html) for the basic memory setup. + +* toc +{:toc} + +## Overview + +<br /> +<center> + <img src="{{ site.baseurl }}/fig/detailed-mem-model.svg" width="300px" alt="Simple memory model" usemap="#simple-mem-model"> +</center> +<br /> + +The following table lists all memory components, depicted above, and references Flink configuration options +which affect the size of the respective components: + +| **Component** | **Configuration options** | **Description** | +| :-------------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | +| [Framework Heap Memory](#framework-memory) | [`taskmanager.memory.framework.heap.size`](../config.html#taskmanager-memory-framework-heap-size) | JVM heap memory dedicated to Flink framework (advanced option) | +| [Task Heap Memory](mem_setup.html#task-operator-heap-memory) | [`taskmanager.memory.task.heap.size`](../config.html#taskmanager-memory-task-heap-size) | JVM heap memory dedicated to Flink application to run operators and user code | +| [Managed memory](mem_setup.html#managed-memory) | [`taskmanager.memory.managed.size`](../config.html#taskmanager-memory-managed-size) <br/> [`taskmanager.memory.managed.fraction`](../config.html#taskmanager-memory-managed-fraction) | Native memory managed by Flink, reserved for sorting, hash tables, caching of intermediate results and RocksDB state backend | +| [Framework Off-heap Memory](#framework-memory) | [`taskmanager.memory.framework.off-heap.size`](../config.html#taskmanager-memory-framework-off-heap-size) | [Off-heap direct (or native) memory](mem_setup.html#configure-off-heap-memory-direct-or-native) dedicated to Flink framework (advanced option) | +| [Task Off-heap Memory](mem_setup.html#configure-off-heap-memory-direct-or-native) | [`taskmanager.memory.task.off-heap.size`](../config.html#taskmanager-memory-task-off-heap-size) | [Off-heap direct (or native) memory](mem_setup.html#configure-off-heap-memory-direct-or-native) dedicated to Flink application to run operators | +| Network Memory | [`taskmanager.memory.network.min`](../config.html#taskmanager-memory-network-min) <br/> [`taskmanager.memory.network.max`](../config.html#taskmanager-memory-network-max) <br/> [`taskmanager.memory.network.fraction`](../config.html#taskmanager-memory-network-fraction) | Direct memory reserved for data record exchange between tasks (e.g. buffering for the transfer over the network), it is a [capped fractionated component](#capped-fractionated-components) of the [total Flink memory](mem_setup.html#configure-total-memory) | +| [JVM metaspace](#jvm-parameters) | [`taskmanager.memory.jvm-metaspace.size`](../config.html#taskmanager-memory-jvm-metaspace-size) | Metaspace size of the Flink JVM process | +| JVM Overhead | [`taskmanager.memory.jvm-overhead.min`](../config.html#taskmanager-memory-jvm-overhead-min) <br/> [`taskmanager.memory.jvm-overhead.max`](../config.html#taskmanager-memory-jvm-overhead-max) <br/> [`taskmanager.memory.jvm-overhead.fraction`](../config.html#taskmanager-memory-jvm-overhead-fraction) | Native memory reserved for other JVM overhead: e.g. thread stacks, code cache, garbage collection space etc, it is a [capped fractionated component](#capped-fractionated-components) of the [total process memory](mem_setup.html#configure-total-memory) | +{:.table-bordered} +<br/> + +As you can see, the size of some memory components can be simply set by the respective option. +Other components can be tuned using multiple options. + +## Framework Memory + +The *framework heap memory* and *framework off-heap memory* options are not supposed to be changed without a good reason. +Adjust them only if you are sure that Flink needs more memory for some internal data structures or operations. +It can be related to a particular deployment environment or job structure, like high parallelism. +In addition, Flink dependencies, such as Hadoop may consume more direct or native memory in certain setups. + +<span class="label label-info">Note</span> Neither heap nor off-heap versions of framework and task memory are currently isolated within Flink. +The separation of framework and task memory can be used in future releases for further optimizations. + +## Capped Fractionated Components + +This section describes the configuration details of the following options which can be a fraction of a certain +[total memory](mem_setup.html#configure-total-memory): + +* *Network memory* can be a fraction of the *total Flink memory* +* *JVM overhead* can be a fraction of the *total process memory* + +See also [detailed memory model](#overview). + +The size of those components always has to be between its maximum and minimum value, otherwise Flink startup will fail. Review comment: ```suggestion The size of these components always has to be between its minimum and maximum value. Otherwise Flink's startup will fail. ``` ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
