# Allowing queues to use nodes based on time **URL:** \ **Category:** Users/Site Administrators\ **Created:** [March 22, 2023, 7:28pm UTC](https://community.openpbs.org/t/allowing-queues-to-use-nodes-based-on-time/3475 "2023-03-22T19:28:02Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![mgasp](https://avatars.discourse-cdn.com/v4/letter/m/3be4f8/32.png) [@mgasp](https://community.openpbs.org/u/mgasp)\ **Post date:** [March 22, 2023, 7:28pm UTC](https://community.openpbs.org/t/allowing-queues-to-use-nodes-based-on-time/3475/1 "2023-03-22T19:28:02Z")
I have two queues, a small queue and a long queue. The long queue has nodes with more cores and memory, while the small queue has nodes with less cores and memory. I want to do the following: - Restrict usage of small nodes to only small jobs during work hours - Allow usage of small nodes by long jobs during non work hours - Restrict number of small jobs per user on small queue during work hours - Restrict number of long jobs per user on small queue during non work hours Primetime may work for this but I want jobs to run all time, I.E jobs should be able to run 24/7, as users may have scripts that run overnight and spawn new jobs so use primetime/non-primetime to prevent jobs from running would not be ideal. ---
**Author:** ![speleolinux](https://avatars.discourse-cdn.com/v4/letter/s/779978/32.png) [@speleolinux](https://community.openpbs.org/u/speleolinux)\ **Post date:** [March 24, 2023, 4:40am UTC](https://community.openpbs.org/t/allowing-queues-to-use-nodes-based-on-time/3475/2 "2023-03-24T04:40:15Z")
An easy method would be to schedule qmrg commands at the start and end of work hours using cron. At the start of the work day cron would run: qmgr -c “set queue smallq resources\_max.mem = 32gb” qmgr -c “set queue smallq resources\_max.ncpus = 4” At the end of the work day cron would run: qmgr -c “set queue smallq resources\_max.mem = 256gb” qmgr -c “set queue smallq resources\_max.ncpus = 32” set queue smallq resources\_max.walltime = 12:00:00 Existing small jobs will continue to run. Big jobs can then start. But after 12 hours they will end and small jobs can start shuffling in. Mike ---
**Author:** ![adarsh](https://avatars.discourse-cdn.com/v4/letter/a/f07891/32.png) [@adarsh](https://community.openpbs.org/u/adarsh)\ **Post date:** [March 24, 2023, 3:11pm UTC](https://community.openpbs.org/t/allowing-queues-to-use-nodes-based-on-time/3475/3 "2023-03-24T15:11:43Z")
> [@mgasp](#): > > - Restrict usage of small nodes to only small jobs during work hours > - Allow usage of small nodes by long jobs during non work hours > - Restrict number of small jobs per user on small queue during work hours > - Restrict number of long jobs per user on small queue during non work hours To our understanding , could you please explain what do you mean by small jobs (with a qsub request example) and same for long jobs. This will help . Thank you ---
**Author:** ![mgasp](https://avatars.discourse-cdn.com/v4/letter/m/3be4f8/32.png) [@mgasp](https://community.openpbs.org/u/mgasp)\ **Post date:** [March 27, 2023, 2:56pm UTC](https://community.openpbs.org/t/allowing-queues-to-use-nodes-based-on-time/3475/4 "2023-03-27T14:56:27Z")
Sure. For example some teams run jobs with 8+ cores and 50+GB of ram like so: qsub -q workq -V -l select=2:ncpus=8:mem=80000M These will run for several days. I haven’t informed my users about walltime yet (although I am planning to with these changes). Smaller jobs would be things like github runners: qsub -q workq -l select=1:ncpus=1:mem=2000M ---
**Author:** ![mgasp](https://avatars.discourse-cdn.com/v4/letter/m/3be4f8/32.png) [@mgasp](https://community.openpbs.org/u/mgasp)\ **Post date:** [March 27, 2023, 2:57pm UTC](https://community.openpbs.org/t/allowing-queues-to-use-nodes-based-on-time/3475/5 "2023-03-27T14:57:03Z")
Very interesting, didn’t think of using qmgr in combination with cron like that. Thanks! ---
**Author:** ![adarsh](https://avatars.discourse-cdn.com/v4/letter/a/f07891/32.png) [@adarsh](https://community.openpbs.org/u/adarsh)\ **Post date:** [March 27, 2023, 7:29pm UTC](https://community.openpbs.org/t/allowing-queues-to-use-nodes-based-on-time/3475/6 "2023-03-27T19:29:24Z")
Implement qlist of small nodes to **smallq** and long nodes to **longq** Ref: [Node-level resource not taking effect - #2 by adarsh](https://community.openpbs.org/t/node-level-resource-not-taking-effect/998/2) You can write a queue job hook that will 1. **accept small jobs** to **smallq** during **work hours** and reject long jobs submitted to small queue ( job requesting more than 1 ncpu and more than 2GB memory per job ) with a message mentioning submit to long queue , as it is working hours. 2. use queue limits for restricting the number of jobs per user to small queue or long (queue job hook maintains the working hours , as it rejects long / short jobs during working/non-working hours respectively) . Refer: [How to assign maximum cores to particular queue? - #2 by adarsh](https://community.openpbs.org/t/how-to-assign-maximum-cores-to-particular-queue/2394/2)