Hi Laxman, In Hadoop-2.8(Not released yet), CapacityScheduler provides configuration for configuring ordering policy. By configuring FAIR_ORDERING_POLICY in CS , probably you should be able to achieve your goal i.e avoiding starving of applications for resources.
org.apache.hadoop.yarn.server.resourcemanager.scheduler.policy.FairOrderingPolicy<S<eclipse-javadoc:%E2%98%82=hadoop-yarn-server-resourcemanager/src%5C/main%5C/java%3Corg.apache.hadoop.yarn.server.resourcemanager.scheduler.policy%7BFairOrderingPolicy.java%E2%98%83FairOrderingPolicy%5dS>> An OrderingPolicy which orders SchedulableEntities for fairness (see FairScheduler FairSharePolicy), generally, processes with lesser usage are lesser. If sizedBasedWeight is set to true then an application with high demand may be prioritized ahead of an application with less usage. This is to offset the tendency to favor small apps, which could result in starvation for large apps if many small ones enter and leave the queue continuously (optional, default false) Community Issue Id : https://issues.apache.org/jira/browse/YARN-3463 Thanks & Regards Rohith Sharma K S From: Laxman Ch [mailto:[email protected]] Sent: 29 September 2015 13:36 To: [email protected] Subject: Re: Concurrency control Bouncing this thread again. Any other thoughts please? On 17 September 2015 at 23:21, Laxman Ch <[email protected]<mailto:[email protected]>> wrote: No Naga. That wont help. I am running two applications (app1 - 100 vcores, app2 - 100 vcores) with same user which runs in same queue (capacity=100vcores). In this scenario, if app1 triggers first occupies all the slots and runs longs then app2 will starve longer. Let me reiterate my problem statement. I wanted "to control the amount of resources (vcores, memory) used by an application SIMULTANEOUSLY" On 17 September 2015 at 22:28, Naganarasimha Garla <[email protected]<mailto:[email protected]>> wrote: Hi Laxman, For the example you have stated may be we can do the following things : 1. Create/modify the queue with capacity and max cap set such that its equivalent to 100 vcores. So as there is no elasticity, given application will not be using the resources beyond the capacity configured 2. yarn.scheduler.capacity.<queue-path>.minimum-user-limit-percent so that each active user would be assured with the minimum guaranteed resources . By default value is 100 implies no user limits are imposed. Additionally we can think of "yarn.nodemanager.linux-container-executor.cgroups.strict-resource-usage" which will enforce strict cpu usage for a given container if required. + Naga On Thu, Sep 17, 2015 at 4:42 PM, Laxman Ch <[email protected]<mailto:[email protected]>> wrote: Yes. I'm already using cgroups. Cgroups helps in controlling the resources at container level. But my requirement is more about controlling the concurrent resource usage of an application at whole cluster level. And yes, we do configure queues properly. But, that won't help. For example, I have an application with a requirement of 1000 vcores. But, I wanted to control this application not to go beyond 100 vcores at any point of time in the cluster/queue. This makes that application to run longer even when my cluster is free but I will be able meet the guaranteed SLAs of other applications. Hope this helps to understand my question. And thanks Narasimha for quick response. On 17 September 2015 at 16:17, Naganarasimha Garla <[email protected]<mailto:[email protected]>> wrote: Hi Laxman, Yes if cgroups are enabled and "yarn.scheduler.capacity.resource-calculator" configured to DominantResourceCalculator then cpu and memory can be controlled. Please Kindly furhter refer to the official documentation http://hadoop.apache.org/docs/r1.2.1/capacity_scheduler.html But may be if say more about problem then we can suggest ideal configuration, seems like capacity configuration and splitting of the queue is not rightly done or you might refer to Fair Scheduler if you want more fairness for container allocation for different apps. On Thu, Sep 17, 2015 at 4:10 PM, Laxman Ch <[email protected]<mailto:[email protected]>> wrote: Hi, In YARN, do we have any way to control the amount of resources (vcores, memory) used by an application SIMULTANEOUSLY. - In my cluster, noticed some large and long running mr-app occupied all the slots of the queue and blocking other apps to get started. - I'm using Capacity schedulers (using hierarchical queues and preemption disabled) - Using Hadoop version 2.6.0 - Did some googling around this and gone through configuration docs but I'm not able to find anything that matches my requirement. If needed, I can provide more details on the usecase and problem. -- Thanks, Laxman -- Thanks, Laxman -- Thanks, Laxman -- Thanks, Laxman
