yangwwei commented on a change in pull request #41: URL: https://github.com/apache/incubator-yunikorn-site/pull/41#discussion_r608847699
########## File path: docs/user_guide/gang_scheduling.md ########## @@ -0,0 +1,205 @@ +--- +id: gang_scheduling +title: Gang Scheduling +--- + +<!-- +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. +--> + +## What is Gang Scheduling + +When Gang Scheduling is enabled, YuniKorn schedules the app only when +the app’s minimal resource request can be satisfied. Otherwise, apps +will be waiting in the queue. Apps are queued in hierarchy queues, +with gang scheduling enabled, each resource queue is assigned with the +maximum number of applications running concurrently with min resource guaranteed. + + + +:::note +gang scheduling feature is only available in *0.10.0* and later releases. +::: + +## Enable Gang Scheduling + +There is no cluster-wide configuration needed to enable Gang Scheduling. +The scheduler actively monitors the metadata of each app, if the app has included +a valid taskGroups definition, it will be considered as gang scheduling desired. + +:::info Task Group +A task group is a “gang” of tasks in an app, these tasks are having the same resource profile +and the same placement constraints. They are considered as homogeneous requests that can be +treated as the same kind in the scheduler. +::: + +### Prerequisite + +It is recommended to enable gang scheduling at least in the *queue level*, which means for +each resource queue, either all the apps are gang scheduled, or non of the apps is gang scheduled. +For the queues which have gang scheduling enabled, the queue sorting policy needs to be set either Review comment: Removed that to avoid confusion -- 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: [email protected]
