Site Support Team - Documentation
Link Commissioning

There is a thorough set of tests to initially commission a site. Those tests cover the complete set of use cases for a site. Initial commissioning of a site is likely to be somewhat labor intensive. After a site is commissioned, it stays commissioned unless a much smaller set of tests indicates that the site consistently fails to meet expectations for some time.

Requirements for Commissioning a site

https://twiki.cern.ch/twiki/pub/CMSPublic/PADASiteCommissioning/Site_Commissioning.doc

Also find in the same file:

• Proposed hurdles for a site to be dropped from “commissioned” to “problematic”
• Proposed hurdles for a site to move from “problematic” to “commissioned”:

Requirements for the "Commissioned Links" metric

https://cms-site-readiness.web.cern.ch/cms-site-readiness/CommLinksReports/HTML/CommissionedLinks_Sites.html

"Site status for T1::downlinks/uplinksT1s (Requirement: T1 needs >= 4 DDT commissioned uplinks and downlinks, respectively, with other T1 sites)"

"Site status for T2::uplinkT1s (Requirement: T2 needs >= 2 commissioned uplinks to T1 sites)."

"Site status for T2::downlinkT1s (Requirement: T2 needs >= 4 commissioned downlinks from T1 sites)."

"Site status for T1::uplinksT2s (Requirement: T1 needs >= 20 DDT commissioned uplinks to T2 sites)."

Requirements for the "Good Links" metric

Inclusion of 'good links' on Site Readiness:

https://twiki.cern.ch/twiki/bin/viewauth/CMSPublic/PADASiteCommissioning#ScGoodLinks

"The metric takes into account Data Transfer Qualities as measured by a properly averaged LoadTest transfers (Debug) and Production transfers (Prod) for all DDT-commissioned links. A link is considered good if the transfer quality (in Prod+Debug) is better than 50%, and then a site is good if at least 50% of the the links are good, for all kind of links-group, which are considered separately."

Good Links view in SSB:

http://dashb-ssb.cern.ch/dashboard/request.py/siteview?expand=86#currentView=default&highlight=true

Procedure and metrics for link commissioning

Links are created in all three instances of PhEDEx (Prod, Debug and Dev).

• The Prod links are disabled until the Debug links demonstrate sufficient speed.
• First, several Debug transfers will be injected to and from the new site and they will be monitored if they start and run OK.
  • Phedex Debug Activity.
• If the Debug Transfers work, then the rest of the transfers can be injected to have full matrix with all T1s, and then, when those succeed, the Prod links will be enabled automatically by overnight cronjobs.

Data Transfer Link Commissioning Procedures

• https://twiki.cern.ch/twiki/bin/view/CMSPublic/CompOpsTransferTeamLinkCommissioning

Links:

• https://twiki.cern.ch/twiki/bin/viewauth/CMS/DDT
• https://twiki.cern.ch/twiki/bin/view/CMS/DebuggingDataTransfers
• The DDT twiks are very old but still valid.