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Hi, This message from Andy didn't make it to the list. Cheers, Remi Begin forwarded message: > From: Andrew Hanushevsky <[log in to unmask]> > Date: November 25, 2004 11:20:27 AM PST > To: Remi Mommsen <[log in to unmask]> > Subject: Re: Status of xrootd from the skim production perspective > > Hi Remi, > >> I don't say it crashes, but it caches the results (sorry for the typo, >> but it should have been clear from the context). > Sorry, I misread that. > >> If you ask the load balancer for a file at a time this file does not >> exists, it claims the file does not exists for several hours (8 ?) >> even >> when the file was created in the meantime. The opposite is true as >> well: if you delete a file, the load balancer still reports that the >> file exists and reports even a checksum for files which were deleted >> hours before. > Yes, I see what is happening now. Not to worry, I can correct that very > easily and will do so by tommorrow. > >> Another issue is when the copy of files into xrootd fails. We copy the >> file (with xrdcp) and then ask for the checksum of the copied file and >> compare it to the local checksum. Assume that the copy corrupted the >> file and the checksums do not match. We want to delete the file and >> retransfer it. But the load balancer will keep reporting the cached >> (wrong) checksum regardless if the retransfer copied the file >> correctly >> or not. > This I don't understand. So, we will have to look at it more closely. > If > you delete the file, and retransfer it, it should give you the > checksum of > the new file, not the old file. This assumes that everything happened > as I > outlined. Again, this will require a closer look to see what it > actually > happening. > >> I hope it became clear that we either have to switch off the caching >> (if that is possible) or to make the caching more clever. I guess the >> latter will be hard as long as xrdcp does not work via the load >> balancer. > Nope, we'll just correct the oversight that xrootd is not reporting > newly created files. > > Andy > > --------------------------------------------------------------------- I haven't lost my mind - it's backed up on my disk somewhere. ********************************************************************* Remigius K. Mommsen e-mail: [log in to unmask] University of California, Irvine URL: http://cern.ch/mommsen c/o SLAC voice: ++1 (650) 926-3595 2575 Sand Hill Road #35 fax: ++1 (650) 926-3882 Menlo Park, CA 94025, US home: ++1 (650) 233-9041 *********************************************************************