requirements

• All processing, production and analysis except the T0 uses EOS and the T2_CH_CERN endpoint per default
  • this includes local submission and GRID submission
  • write permissions are handled through …
• The T0 uses two special scenarios which we should be able to switch in the T0 configuration
  • default mode: access and write files from/to both EOS and Castor and register to T0_CH_CERN
    • /store/data on Castor -> tape
    • /store/t0temp and /store/temp and /store/unmerged on EOS
    • /store/t0streamer on Castor -> disk only
    • /store/streamer on Castor -> tape
    • /store/express on EOS
  • test mode: access and write files only from/to EOS and register to T2_CH_CERN
    • /store/data on EOS
    • /store/t0temp and /store/temp and /store/unmerged on EOS
    • /store/t0streamer on Castor
    • /store/streamer on Castor
    • /store/express on EOS

TFC switch for T0

• The TFC gets read by the framework from $CMS_PATH/SITECONF/local/JobConfig/site-local-config.xml
• At CERN, this points to the T2_CH_CERN TFC which only provides access to EOS

• For the T0, there are two overrides in place to support the default mode (mixed Castor/EOS):
  • The T0 stageout code can be overridden with an environment variable to use $CMS_PATH/SITECONF/T0_CH_CERN/JobConfig/site-local-config.xml
  • The PoolSource gets an override TFC parameter set during configuration manipulation, the override TFC is in $CMS_PATH/SITECONF/T0_CH_CERN/JobConfig/

• For right now we will add an entry in $CMS_PATH/SITECONF/T0_CH_CERN/JobConfig/site-local-config.xml to configure reads from /store/data/WMAT0Commissioning to use EOS. That way we can quickly support WMAT0 commissioning activities on EOS.

• Longterm and to also support overrides for other sites, we'll make both the stageout override and the PoolSource overrides configurable in the Spec. The later is already in the spec and just needs to be added to the reqmgr UI, the former needs to be implemented from scratch and will replace the environment variable override option.

Future plans

• When the TransferSystem is able to copy files to EOS, move /store/streamer and /store/t0streamer to EOS to benefit from better replication and larger spread over disk servers to allow for higher throughput