Question re global.cylc[platforms][<platform name>]hosts

Cylc Cylc Support
1

I am trying to come up with the best way to describe the the environment of ECMWF’s HPC center.
I have this:

   [[ecmwf_login]]
        hosts = hpc-login
        job runner = background
        communication method = poll
        retrieve job logs = True
        install target = hpc-login

    [[ecmwf_compute]]
        hosts = hpc-login
        job runner = slurm
        retrieve job logs =True
        communication method = poll
        install target = hpc-login

But it’s not quite right. “hpc-login” is what we ssh to, but the actual hosts are named a[a-z]\d-\d{3,} , and compute nodes with a similar pattern. This causes issues with job running in bg on ecmwf_login. I’ve solved the some issue on our local MeteoFrance hpc:

    [[belenos-bg1]]
        hosts = belenoslogin1
        cylc path = /home/ext/mr/smer/turekg/miniconda3/envs/cylc/bin
        job runner = background
        retrieve job logs = True
        install target = belenos
        execution polling intervals = PT1M

    [[belenos-bg2]]
        hosts = belenoslogin2
        cylc path = /home/ext/mr/smer/turekg/miniconda3/envs/cylc/bin
        job runner = background
        retrieve job logs = True
        install target = belenos
        execution polling intervals = PT1M

    [[belenos-bg3]]
        hosts = belenoslogin3
        cylc path = /home/ext/mr/smer/turekg/miniconda3/envs/cylc/bin
        job runner = background
        retrieve job logs = True
        install target = belenos
        execution polling intervals = PT1M

[platform groups]

    [[belenos_login]]
        # pick one of these platforms to run operations on
        platforms = belenos-bg1, belenos-bg2, belenos-bg3

so if I designate a platform [[ a[a-z]\d-\d{3,} ]] what is hosts = ?
and then what would be platforms = ? for a platform group named [[ecmwf_login]] ?
Thanx!