[slurm-users] Increasing job priority based on resources requested.

mercan ahmet.mercan at uhem.itu.edu.tr
Fri Apr 19 15:41:13 UTC 2019


Hi;

We use node weight parameter to do that. When you set High mem nodes 
with high weight, and low mem nodes with low weight; Slurm will select 
lowest weight nodes which have enough mem job requested. So, if there 
are free low mem nodes, high mem nodes will stay free. At our cluster, 
low mem nodes have weight as 10, and high mem nodes have weights 100-400.

Ahmet M.


19.04.2019 18:27 tarihinde Prentice Bisbal yazdı:
> Ryan,
>
> I certainly understand your point of view, but yes, this is definitely 
> what I want. We only have a few large memory nodes, so we want jobs 
> that request a lot of memory to have higher priority so they get 
> assigned to those large memory nodes ahead of lower-memory jobs which 
> could run anywhere else. But we don't want those nodes to sit idle if 
> there's jobs in the queue that need that much memory. Similar idea for 
> IB - nodes that need IB should get priority over nodes that don't
>
> Ideally, I wouldn't have such a heterogeneous environment, and then 
> this wouldn't be needed at all.
>
> I agree this opens another avenue for unscrupulous users to game the 
> system, but that (in theory) can be policed by looked at memory 
> requested vs. memory used in the accounting data to identify any 
> abusers and then give them a stern talking to.
>
> Prentice
>
>
> On 4/18/19 5:27 PM, Ryan Novosielski wrote:
>> This is not an official answer really, but I’ve always just 
>> considered this to be the way that the scheduler works. It wants to 
>> get work completed, so it will have a bias toward doing what is 
>> possible vs. not (can’t use 239GB of RAM on a 128GB node). And 
>> really, is a higher priority what you want? I’m not so sure. How soon 
>> will someone figure out that they might get a higher priority based 
>> on requesting some feature they don’t need?
>>
>> -- 
>> ____
>> || \\UTGERS, |---------------------------*O*---------------------------
>> ||_// the State     |         Ryan Novosielski - novosirj at rutgers.edu
>> || \\ University | Sr. Technologist - 973/972.0922 (2x0922) ~*~ RBHS 
>> Campus
>> ||  \\    of NJ     | Office of Advanced Research Computing - MSB 
>> C630, Newark
>>       `'
>>
>>> On Apr 18, 2019, at 5:20 PM, Prentice Bisbal <pbisbal at pppl.gov> wrote:
>>>
>>> Slurm-users,
>>>
>>> Is there away to increase a jobs priority based on the resources or 
>>> constraints it has requested?
>>>
>>> For example, we have a very heterogeneous cluster here: Some nodes 
>>> only have 1 Gb Ethernet, some have 10 Gb Ethernet, and others have 
>>> DDR IB. In addition, we have some large memory nodes with RAM 
>>> amounts ranging from 128 GB up to 512 GB. To allow a user to request 
>>> IB, I have implemented that as a feature in the node definition so 
>>> users can request that as a constraint.
>>>
>>> I would like to make it that if a job request IB, it's priority will 
>>> go up, or if it requests a lot of memory (specifically 
>>> memory-per-cpu), it's priority will go up proportionately to the 
>>> amount of memory requested. Is this possible? If so, how?
>>>
>>> I have tried going through the documentation, and googling, but 
>>> 'priority' is used to discuss job priority so much, I couldn't find 
>>> any search results relevant to this.
>>>
>>> -- 
>>> Prentice
>>>
>>>
>



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