Configuring PPTransfer

The now-recommended method for transferring data between ARCHER2 and JASMIN is using GridFTP using certificate authentication. This allows data transfers to run on the ARCHER2 serial nodes using certificate-based authentication rather than SSH. Certificates are valid for up to a month from initiation and can be easily extended/regenerated for longer running simulations.

These instructions show how to setup your GridFTP certificate and modify a suite to run the pptransfer task on the ARCHER2 serial nodes to push the data across to JASMIN from ARCHER2 /work disk.

Note: In order to use GridFTP to JASMIN you must have access to the hpxfer (High Performance Data Transfer Service). Access can be requested via the JASMIN Accounts Portal.

Obtaining a JASMIN short-lived credential

• Login to ARCHER2.

• Change directory to your ARCHER2 work directory - /work/n02/n02/USERNAME.

• [First Time Only] “Bootstrap trust” to setup your local certificate store with those needed to interact with the JASMIN server.

  $ $UMDIR/bin/onlineca-get-trustroots-wget.sh -U https://slcs.jasmin.ac.uk/trustroots/ -b
  Bootstrapping Short-Lived Credential Service root of trust.
  Trust roots have been installed in /home/n02/n02/USERNAME/.globus/certificates.
  

• Obtain a short-term credential (this must be called cred.jasmin) using your JASMIN accounts portal username USERNAME.

  $ $UMDIR/bin/onlineca-get-cert-wget.sh -U https://slcs.jasmin.ac.uk/certificate/ -l USERNAME -o ./cred.jasmin
  

  When prompted for a passphrase, this is the password associated with your JASMIN account portal account (NOT your SSH passphrase)

• Change the permissions on the newly-created cred.jasmin file so that it is only readable by you.

  $ chmod 600 cred.jasmin

This credential is valid, by default, for 30days. You can see the validity period by inspecting the certificate using the following command:

$ openssl x509 -in cred.jasmin -noout -startdate -enddate
notBefore=Mar 11 17:32:59 2022 GMT
notAfter=Apr 10 17:32:59 2022 GMT

This means you can use this certificate for the following 30days, after which you will need to repeat this step to obtain a new one.

A fuller explanation of the process is given in the document Data Transfer Tools: GridFTP (certificate-based authentication)

Suite Settings

These settings assume you are using the ARCHER2/JASMIN version of postproc as detailed on the Post-Processing page and wish to automatically delete data from ARCHER2 after successful transfer to JASMIN.

• In panel “postproc -> Post Processing - common settings -> ARCHER2-JASMIN Archiving” set archive_root_path to be $ROSE_DATAC. This evaluates to cylc-run/<suiteid>/share/cycle.

• In panel “postproc -> Post Processing - common settings -> ARCHER2-JASMIN Archiving -> Data Transfer”:

  • Set transfer_dir to be a directory on your Jasmin group workspace (e.g. /gws/nopw/j04/ncas_cms/aosprey/archive) or on the JASMIN Transfer Cache (e.g. /work/xfc/vol5/user_cache/rshatcher/archive)
  • Set transfer_type to Push
  • Set remote_host to gridftp1.jasmin.ac.uk
  • Set gridftp to true

Note: See u-bc613/archer2 for a complete working postproc and pptransfer example suite.