MinutesFAXFeb21

Coordinates

• 11:00 Central
• 866-740-1260 (U.S.& Canada)
• access code: 8408432
• Attending: Doug, Wei, Rob, Charles, Saul, Patrick, Tom

Topics

Topics to be discussed (from Wei):

• N2N
• Review of GUID handling
• DQ2 client update
• checksums
• X509 security
• "Proxy cluster"

and,

• hammer cloud tests
• Status of xrootd at sites (schedule for functionality? testing w/ Hiro's datasets)
• others? VDT rpm status? xrd clients (eg. wide area)?

N2N issues

• What if LFC is moved to CERN
• Needs to go away for the long term
• Charles proposal - get rid of DQ2 underscore. A heuristic to cover different mappings - for the plugin - want to minimize this. T3's will have a standard PD2P global namespace.
• Working with Simone for a solution to DQ2 underscore.
• What happens with PD2P datasets, because they are too big.
• Will require re-normalize paths on the T2's.
• Charles will assess the renormalization required at the sites.
• Canonical format from Angelo's talk at last SW week. May need to discuss details with him. There is link in the Tier 3 twiki.

GUID handling

• We have already proposed solution?
• Have we backed off on using the guid as lookup
• Use extended attribute to store guid; have code preserve all extended attributes.

Checksum verification (higher priority)

• Using global name space to access T2 files via Xrootd requires N2N? translation.
• Xrootd currently use an external tool to calculate checksum (and store in extended attribute)
• For Xrootd servers serving FAX users, currently global name space is passed as parameter to the checksum tool, not the N2N? translated physical path in the storage (so the external tool has to do its own N2N? )
• Working on integrating checksum tool into Xrootd to utilized Charles' N2N? translation plug-in.

X509 security

• Andy is working on this
• Put X509 for reading will be sufficient; distinguish from look ups.

Proxy cluster

• for scalability reasons - to eliminate single point of failure for serving from a xrootd cluster to the outside world.

Proxy server

• Doug has tested a single proxy machine
• 3.0.2 rpm's from OSG needs to be tested
• Also regulates the traffic

hammer cloud tests

• Charles is running hammer cloud tests
• Will circulate a summary of tests

Misc

• Status of xrootd at sites (schedule for functionality? testing w/ Hiro's datasets)
• Need active proxy, with voms extensions

others? VDT rpm status? xrd clients (eg. wide area)?

• VDT rpm far away from generic deployment
• xrd client - no development for now Charles.

dq2-client

• In development release; data path normalized, to return the global path
• rc4

References

• AtlasFederatedXrootd
• XrootdSitesUSATLAS
• https://twiki.cern.ch/twiki/bin/viewauth/Atlas/AtlasXrootdSystems

-- RobertGardner - 21 Feb 2011