Broadcast in rose suite to send data from Archer2 to Puma

Hi I have been trying to get this to work:

  • run a rose suite on PUMATEST
  • it causes a simple task to run on Archer2
  • that task tries to broadcast a resulting string from Archer2 back to Puma
  • so a task on Puma can proceed using the data sent by Archer2.

I am not sure how PUMATEST-Archer2 links are set up, but see from Cycl
Pass variable between tasks - Cylc Support - Cylc Workflow Engine
that “Broadcasts require http(s) or ssh+http(s) task comms (i.e. can’t work with polling task comms)”

References I’ve looked at include

My trial suite is
pumatest : /home/mjm/roses/bcast1

On archer2, /home/n02/n02/mjmn02/cylc-run/bcast1
The suite fails in the broadcast.

Of course I might just have an error in the suite but I also wonder if broadcast can work for archer2-PUMA in light of the comment above about polling.

Hi Mike,

We use “task polling” as the communications for cylc between puma/pumatest & ARCHER2 so that’s why broadcasting from remote tasks won’t work. We had to go with this last resort option as it was not possible to communciate out of ARCHER.

It’s possible that https might work out of ARCHER2 - we’ve not tried it since we’re in the process of replacing puma/pumatest. Obviously you are welcome to give it a go, but I wouldn’t be surprised if pumatest isn’t then configured correctly to allow that either.

Once puma is within the ARCHER2 trustzone we should then be able to use the default cylc https communications and broadcasting will then be possible.


Thanks Ros.
We were using the broadcast as a stop-gap until (here I’d like to check I am making a correct assumption,) we can ssh from archer2 onto newPUMA without needing passwords.
Will we be able to run commands using ssh from Archer2 batch jobs in the serial queue?
Is there yet a target time for the new PUMA?

Hi Mike,

Yes, I believe it will possible to get from ARCHER2 to new PUMA without password and obviously vice-versa, I guess in the same manner that you could get from the 23-cab to 4-cab without password but details still need to be finalised.

Yes you can run ssh from ARCHER2 serial batch jobs so long as there is no authentication required (including no use of ssh-agents).

ARCHER2 are waiting on delivery of the new PUMA hardware. As I’m sure you’re aware there are global supply chains issues so it is taking somewhat longer than it usually would frustratingly. Once we’ve physically got the hardware we’ll be in more of a position to give a timeline.