r10 - 05 Oct 2011 - 19:44:08 - WeiYangYou are here: TWiki >  Admins Web > FederatedXrootdWorkshopSep2011

FederatedXrootdWorkshopSep2011

Background

Physics benchmarking tools

References

Xrootd ATLAS Tier 3

Xrd-LFC, ATLAS (Tier 1, Tier 2)

Xrootd official sources

VDT

Xrootd in dCache

Monitors

Various


Site configruations, FRM scripts, etc

Temporary spot for configuration files

ANL T3

DUKE T3

UChicago T3

BNL T3

ANL T3

UTA T3

SLAC Tier 2

SLAC T3 is a Proof farm. The xrootd components of the Proof farm use non-rpm xrootd 3.0.5 release in order to avoid library and binary conflict with the root package for Proof. The proxy machine to the farm used the xrootd RPMs.

OST ITB


Using dq2-get with Xrootd's xprep and passing info to the FRM scripts:

From Hiro
The following shows how to use dq2-get with xrootd plugin (assuming that
you have atlas federated xrootd storage with working FRM)

1.  Need pacman client (see
https://atlaswww.hep.anl.gov/twiki/bin/view/Tier3Setup/SoftwareInstallation#Pacman_installation 
or any other instructions.)

2. Get the dq2-get with testing version.
pacman -trust-all-caches -allow tar-overwrite -get
http://atlas.web.cern.ch/Atlas/GROUPS/DATABASE/project/ddm/releases/pacman/cache:DQ2ClientsTesting

3.  Edit DQ2_INSTALL_DIR/DQ2Clients/opt/dq2/etc/dq2.cfg
Add the following in the [dq2-clients] section (at the bottom)
XRDCP=xrdcp.XRDCPdownloader
XPREP=xprep.XPREPdownloader

(so, it should look like)
[dq2-clients]
FTS=fts.FTSdownloader
XRDCP=xrdcp.XRDCPdownloader
XPREP=xprep.XPREPdownloader

4.  Fix the bug in DQ2_INSTALL_DIR/DQ2Clients/opt/dq2/lib/dq2/clientapi/cli/util/GetDatasetThread.py
  There is a bug in the recent release of client code.  Until it is
fixed, one can get the one with the temporary fix at
  http://www.usatlas.bnl.gov/~hiroito/dq2/GetDatasetThread.py

 The detail of the bug can be seen within the bug report at
http://savannah.cern.ch/bugs/?86475

5.  issue the dq2-get command
dq2-get -L site -q XPREP -S DESTINATION_XROOTD DATASET_NAME

(note: -L "site" (or default site in env) is necessary although it is a
bit counter intuitive in terms of the concept of the federation.) 

using the real value.  It will look like

dq2-get  -L BNL-OSG2_DATADISK -q XPREP -S bnlt3s01.usatlas.bnl.gov:1094 
mc11_valid.113642.Pythia8JetsJ7.recon.log.e789_a124_tid365181_00

Open Technical Issues

The following are open technical issues we concluded from this workshop that we wish to be addressed ASAP. The orders doesn't reflect priorities.

  1. N2N2? : We need it in order to pass opaque info such as GUID. We discussed making GFN symlinks but some sites think the amount of data they have is too large, and maintenance is also an issue. A related one is the current N2N? module. How easy it is to make it work with N2N2? ? We need to extend it to suppose GUID. Many of use have read the code. We need to model to support it. A community model or a ownership model? For latter, who will own it?
  2. Intergrated cheksuming. It is needed while N2N? (2) is required. There are discussion of caching N2N? (2) results for various future use. A related issue is how to do checksum on Xrootd native proxy (or proxy consists if a xrootd on top of xrootdfs). Andy thinks the former can be addressed by a plugin. Will get more detail.
  3. Reading from Native Proxy triggers stage-in (reading from global redirector will not).
  4. Issuses in "sss": private/public address NICs; Double free() in sss (Wei got a core dump). The multiple home/NIC issue is not limited to using the "sss" module. But as a broader issue, it may only be addressed after 3.1.0 release.
  5. Does xprep (and dq2-get -xprep) give a warning if site's xrootd cluster is not configured for xprep. At least we need to give sites enough warning so that they don't miss this issue during configuration.
  6. Notifying user of completeness or failure of dq2-get -xprep. It seems we favor letting users to check if files are ready via a dq2-ls against local file system/storage. As Doug pointed out, the global file name dq2-ls produced isn't quite identitical to the GFN we expected (and dq2-get produced?). In this case, who is in the best position to push this to be fixed (with ADC)
  7. Standardize FRM scripts, including authorization, GUID passing, checksum validation and retries.
  8. An updated CMSD that will work with the native dCache/xrootd door (Andy/?)
  9. A caching mechanism to allow the lookup done by the CMSD N2N? [2?] plugin to be useable by the xrootd door (either dCache or Xrootd version) (Andy/Hiro/Wei/?)
  10. A "authorization" plugin for the dCache/xrootd door which uses the cached GFN->LFN information to correctly respond to GFN requests (Hiro/Shawn/?)
  11. Setting up a panda analy queue to run tests against the federation, and therefore using GPN from within the pilot/lsm, testing both direct access and stage-in with HC testing.
  12. Get Shuwe's top DP3D? example into HC (Doug?)

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Attachments


cfg xrootd-proxy.cfg (0.2K) | OferRind? , 13 Sep 2011 - 11:47 | BNL T3 proxy server config
sh stagein.sh (2.3K) | OferRind? , 13 Sep 2011 - 11:44 | BNL T3 FRM staging script
cf xrootd.cf (0.9K) | OferRind? , 13 Sep 2011 - 11:43 | BNL T3 cluster config
org xrootd-clustered.cfg.uct3-xrd.mwt2.org (1.0K) | RobertGardner, 13 Sep 2011 - 07:45 |
edu xrootd-clustered.cfg.uct3-xrdp.uchicago.edu (0.4K) | RobertGardner, 13 Sep 2011 - 07:45 |
slac-t3 xrootd.cf.SLAC-T3 (2.7K) | WeiYang, 17 Sep 2011 - 02:16 | xrootd config file for SLAC Proof farm
slac-t3 stagein.sh.SLAC-T3 (0.5K) | WeiYang, 17 Sep 2011 - 02:17 | FRM stage-in script for SLAC Proof farm
slac-t3 xrootd.proxy.cfg.SLAC-T3 (0.3K) | WeiYang, 05 Oct 2011 - 19:04 | xrootd proxy config for SLAC Proof farm
slac-t2 xrootd.proxy.cfg.SLAC-T2 (0.4K) | WeiYang, 05 Oct 2011 - 19:44 | xrootd proxy config for SLAC Tier 2
 
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