Performance of Rose suite on Monsoon
|Reported by:||cthomas||Owned by:||annette|
|Keywords:||NEMO, NEMOVAR, Rose, perftools||Cc:|
|Platform:||MONSooN||UM Version:||<select version>|
I am running a Rose assimilation suite on Monsoon (and ARCHER) which uses NEMO/CICE and NEMOVAR. There are three main stages which repeat each cycle: the observation operator (obsoper), NEMOVAR, and finally the incremental analysis update (IAU). The suite was primarily developed at the Met Office and was divided into different Rose tasks, which works well on Monsoon but runs into problems on ARCHER due to the significantly longer queues. In order to run the suite more efficiently on ARCHER I have converted the tasks into one monolithic job which uses the same set of processors for all three stages mentioned above instead of claiming and releasing resources each time.
I have two questions about this. Firstly, I am interested in whether it's possible to check the performance of the job on Monsoon using perftools or similar, in order to check for any places where the job could be made more efficient. I found this similar question for the UM (http://cms.ncas.ac.uk/ticket/1711) so I hope there is a similar way to do it for Rose.
Secondly I would be interested to know if any performance gain could be achieved between the IAU and obsoper stages. The IAU produces the analysis from one cycle which is then used as the background in the obsoper stage for the next cycle. At the moment the analysis is written to disk (as a netcdf file) during IAU before being read in again by the obsoper. We were wondering if keeping it in memory is possible at all, and if so, whether doing that would actually bring any benefit. In other words is reading from memory faster or slower than reading from a disk. I think at the very least there might be issues with the namelist (NEMO complains if you have both ln_asmiau and ln_bkgwri set to true, for example), but if that can be overcome then maybe it's possible… I realise this might be a tricky question to answer but if you had any advice I'd be very interested to hear it.
Change History (14)
comment:1 Changed 10 months ago by annette
- Owner changed from um_support to annette
- Status changed from new to assigned
comment:5 Changed 7 months ago by annette
- Resolution set to answered
- Status changed from assigned to closed
comment:7 Changed 7 months ago by cthomas
- Priority changed from low to normal
- Resolution answered deleted
- Status changed from closed to reopened