Data Movement/Awareness Proposal¶
Three major areas:
- job-submission site choice based on data locations
- out of workflow data placement / staging
- data placement stages in workflows
Is there something else people are thinking of? Some sort of predictive dohickey?
it may not belong in POMS then...
Site choice based on data locations (Jobs to Data)¶
- getting data disks/number of files there for a dataset (push to SAM, already a report we wanted?)
- mapping those data disk locations to preferred sites (per-experiment table? also push to SAM?)
- If data is largely available at specific sites, splitting into multiple submissions, each with
- dataset subset on that site's data disks (but not elsewhere?)
- submission tagged to that site
- mop-up submission for files not at those sites
This can be done independently of other options, and can be a new Campaign Stage flag, like split-type.
Out of workflow data placement/staging¶
- finding Campaign Stages likely to launch soon:
- have cron launches pending
- depend on Campaigns that have jobs running
- Users have hand-launched recently
- finding next dataset those Campaign stages will get
- taking appropriate action -- prestaging, transferring to particular sites
So we need an interative screen to let you restrict Campaign Stages involved (at least by exp, etc), and what action to take, and run it; plus we need a scheme to schedule these activities (i.e. via cron)
data placement stages in workflows¶
Need data movement stages to workflows. So this becomes a CampaignStage thats actually a data movement, rather than a job submission. Interesting option is if it is a small job submission under the covers...
But basically, it would schedule a dataset file transfer (possibly by calling a SAM service, or by submitting a job that does sam_clone_dataset, or...) and waiting for it to complete. The only kludgy bit there is we still need to flag it as a transfer stage, because it's output dataset is the parent's output dataset for dependency purposes.