two inner CE: Singularity CE and Pool CE can work together or not?

[zhangxiaomei]

Hi all,
If I want to support multi-core jobs, I need to choose localCEType=Pool. Does mean I can't use Singularity since it is another type of inner CE? Is it possible to use both?

Best regards,
Xiaomei

[aldbr]

Looks like this is not really documented (at least I didn't find the information in the DIRAC documentation).

The Pool computing element (CE) is a special case, it embeds an inner computing element.
By default the Pool CE uses the InProcess CE, which simply executes the job on the machine.
The Pool CE also supports the Singularity CE. To use it, you just have to add the following option in the CE configuration:

InnerCESubmissionType = Singularity

LocalCEType = Pool/Singularity

[zhangxiaomei]

Hi alddr,
Thank you for the reply! I have just done the tests and it looks like only one kind of inner CE type (Pool) was selected if both inner type was defined even with "InnerCESubmissionType":
In the pilot log, I saw "Defining Inner CE from local configuration = Pool", and singularity is not started. The CS configuration I used:
LocalCEType = Pool
NumberOfProcessors = 4
Tag = WholeNode
InnerCESubmissionType = Singularity
ContainerRoot = /cvmfs/juno.ihep.ac.cn/singularity/juno-centos7
Container = Singularity

[aldbr]

Could you try to define LocalCEType as Pool/Singularity and let me know how it goes please?

[aldbr]

Which version of DIRAC are you using by the way?

[zhangxiaomei]

My DIRAC version v7r1p30.

[zhangxiaomei]

I have a try with "LocalCEType = Pool/Singularity". In the end, the piolt use PoolCE, no singularity:
2022-03-15 03:34:59 UTC WorkloadManagement/JobAgent INFO: Defining Inner CE from local configuration = Pool/Singularity
2022-03-15 03:35:19 UTC WorkloadManagement/JobAgent INFO: Submitting JobWrapper Job9267834 to PoolCE

[aldbr]

I created a PR to resolve the issue: #5959.
v7r1 is not supported anymore, so I suggest you to update your DIRAC installation to get the fix (at least v7r2).