Stephen, Brian, Wahid, John H, Andrew Lahiff (CMS), Duncan, Elena, Robert Jens, John B, Sam, Alessandra, Gareth, Pete, Rob, Ewan, Govind, Matt, Chris, Daniela, Mark. At which level does it work? There is a multicast request for the file. WebDAV also tested: ATLAS want to use it for renaming files. Aim to have both xroot and WebDAV; CMS only wanted xroot - deadline end of last year. Is there plan to have local redirectors? For DPM, the head node is a local redirector. GridPP Doc (Chris) https://www.gridpp.ac.uk/wiki/WebDAV CASTOR - all data transfer goes through the redirector (Brian). Know the limitations. StoRM has a separate xroot server, so writing files will not work - and if it worked it would mess up the dynamic space usage as understood by StoRM (Chris); dCache uses it as a "standard" protocol (Chris Brew should have it running), like DPM does. StoRM will support WebDAV "in the next release"; xroot has not been requested - CNAF may be providing something. Multiple VOs could be supported on the same service - in theory. WebDAV would work, but CMS and ATLAS would need two different redirectors. Same box, two different services. Brian will check whether the RALPP redirector is registered for redirection. There is a cost matrix, based on a test job. GDB has not mandated the use of redirection - yet. Will it influence the future data model? Will need to be a member of ATLAS? Should have one dteam? ATLAS have an assumption that everyone at a site which supports ATLAS should be a member of ATLAS. Ewan has been getting files without being an ATLAS member, so checking must be lax. Chris at QMUL is using it for local users. CMS redirection is in production for a while; mainly chasing sites to join and US are well ahead. ``End users should never experience job failures due to data read failure.'' Sites should provide two things: xrootd fallback and xrootd access. There is a currently non-critical test; may become critical. CMS: global redirector at CERN; two in UK, IC and RAL, but not used much at the moment. UK sites are connected to the European redirector. Glasgow has had a test CMS redirector for a while. Which seems to have dropped off the radar. Need to update the site config file - also T3, Stuart sent update request to QMUL, and Chris B to Oxford. CMS experiences - used in production in T2s; might get more interesting experiences with T1s. Caching proxy would be useful to set up - instructions how to set this up would be useful (Chris). Software exists to do this. Are files opened or copied to locally? Sites can configure this. Wahid will try to find out which other activities are going on with redirection. ATLAS T2s in the UK are "encouraged" to join. Doing it now would be advantageous since you could participate in the dress rehearsal. We should probably gain some more experience before fully pushing ahead. AOB Govind - negative space published. Ticket needs reassigning to DPM. Chat Log (10:07:36 AM) fa9a3184b41f4f2b11fa entered the room. (10:07:36 AM) aforti entered the room. (10:07:36 AM) wbhimji entered the room. (10:07:36 AM) ewanmacmahon entered the room. (10:07:36 AM) SSKIPSEY entered the room. (10:07:36 AM) gronbech entered the room. (10:07:36 AM) rfay entered the room. (10:07:36 AM) 7a6fa2fcfc2cffa2ce73 entered the room. (10:07:36 AM) brian entered the room. (10:07:36 AM) j.jensen.ral entered the room. (9:58:40 AM) 7a6fa2fcfc2cffa2ce73: I wish Vidyo would show participants in the main window (9:58:49 AM) wbhimji: I agree of course (9:58:50 AM) 7a6fa2fcfc2cffa2ce73: also, I have a hell of a name on this thing (9:59:05 AM) wbhimji: indeed (who are you?) (9:59:14 AM) brian: test mesage (9:59:20 AM) wbhimji: hello brian (10:02:49 AM) 7a6fa2fcfc2cffa2ce73: I am John. Which leaves a few choices. (10:11:15 AM) ewanmacmahon: It also goes and tries somewhere in the US, as I found when I typo-ed a filename and asked it for something that didn't actually exist. (10:13:13 AM) cwalker entered the room. (10:13:15 AM) cwalker left the room. (10:13:24 AM) fa9a3184b41f4f2b11fa left the room. (10:13:24 AM) cwalker entered the room. (10:14:01 AM) gronbech: Why are not all UK sites listed in http://dashb-atlas-ssb.cern.ch/dashboard/request.py/siteview?view=FAXMON#currentView=FAXMON&highlight=false (10:14:06 AM) fa9a3184b41f4f2b11fa entered the room. (10:14:06 AM) aforti: yes, it's like a DNS (10:14:09 AM) fa9a3184b41f4f2b11fa left the room. (10:14:16 AM) fa9a3184b41f4f2b11fa entered the room. (10:14:23 AM) aforti: it asks to the next level and if it doesn't find it it goes up (10:15:09 AM) SSKIPSEY: Pete: because those are the sites that are known to the FAX. (10:18:16 AM) gronbech: OK I realize only sites in the test will be there but I could not see OX, but I have discovered the scroll bar now:-)) (10:19:40 AM) cwalker: https://www.gridpp.ac.uk/wiki/WebDAV - status of WebDAV and XrootD (10:20:29 AM) ewanmacmahon: For DPM at least, I think we're good on xrootd and federated access; it works well. (10:20:45 AM) ewanmacmahon: webdav doesn't seem to be quite all there yet. (10:22:11 AM) hill entered the room. (10:22:13 AM) hill left the room. (10:22:20 AM) hill entered the room. (10:22:21 AM) hill left the room. (10:22:26 AM) hill entered the room. (10:24:44 AM) hill left the room. (10:31:17 AM) 7a6fa2fcfc2cffa2ce73: We have NAT and our WN-WAN rates are pretty poor (10:33:44 AM) cwalker: http://hammercloud.cern.ch/hc/app/atlas/test/20016672/ (10:34:02 AM) ewanmacmahon: Do you just have a really wheezy NAT box? I'd have thought you'd get a pretty decent fractions of WAN rate with a fairly basic NATting Linux machine. (10:35:17 AM) 7a6fa2fcfc2cffa2ce73: A combo of NAT and Jumbo-standard frames. Might be better on the new kit (10:38:42 AM) ewanmacmahon: You don't need an ATLAS proxy to run the basic 'Can I get this file' tests (10:38:54 AM) 7a6fa2fcfc2cffa2ce73: It's mostly individual throughput, aggregate throughput is fine (10:39:13 AM) drand entered the room. (10:39:16 AM) drand left the room. (10:39:23 AM) drand entered the room. (10:40:25 AM) 7a6fa2fcfc2cffa2ce73: Liverpool have no ATLAS admins (but helpful ATLAS users) (10:43:35 AM) j.jensen.ral: Does it mean we should all be ATLAS members (everyone from a site which supports ATLAS...?) (10:45:46 AM) SSKIPSEY: It means that that's an assumption made by US-ATLAS people. This may or may not be a valid assumption. (10:46:05 AM) j.jensen.ral: OK (10:54:41 AM) ewanmacmahon: Well, CMS need to decide what, if anything, they want from Tier 3 sites (which most of us are) (10:55:56 AM) SSKIPSEY: In the case of Glasgow, it was annoying because at the time there were no other DPM sites with a CMS redirector, and we were trying to help improve the configuration for such. (11:00:06 AM) ewanmacmahon: For anyone with up to date EMI2 DPM, adding xrootd is not terribly difficult. (11:00:15 AM) ewanmacmahon: Also, FWIW, webdav (11:03:56 AM) fa9a3184b41f4f2b11fa left the room. (11:04:12 AM) wbhimji: Action for Ewan - can you restart your xrootd service on all disk nodes (11:04:17 AM) wbhimji: (for the monitoring thing) (11:04:28 AM) ewanmacmahon: Ah, disk nodes too. Right-o. (11:04:47 AM) ewanmacmahon: I'll do that in just a mo. (11:05:05 AM) wbhimji: Thanks! - maybe ping ilija and I when its done - we can check it sorts it - (11:05:08 AM) wbhimji: thanks a lot (11:05:27 AM) aforti left the room. (11:06:36 AM) SSKIPSEY left the room. (11:06:55 AM) ewanmacmahon: OK Wahid; all our xrootds are restarted. (11:07:00 AM) drand left the room. (11:07:00 AM) brian left the room. (11:07:09 AM) gronbech: ewan can you stay on to test my audio (11:07:13 AM) wbhimji: thaanks - will check and get back to you if theres an issue - should be ok (11:07:26 AM) ewanmacmahon: Pete - yes, I can do that. (11:07:51 AM) gronbech: ok I goiing to try talking.... (11:08:17 AM) ewanmacmahon: OK; I heard you. (11:08:31 AM) ewanmacmahon: But not now. (11:10:23 AM) wbhimji: the restart seemed to work by the way ewan from the spike appearing on the right at (11:10:23 AM) wbhimji: http://atl-prod07.slac.stanford.edu:8080/display (11:10:26 AM) wbhimji: bye.. (11:11:35 AM) 7a6fa2fcfc2cffa2ce73 left the room.