CMSSW Fallback

The patch attached to this page allows a CMSSW run to fallback from the normal TFC access to a secondary protocol, such as the global xrootd redirector.

This is only tested on CMSSW_3_8_0 or later.

CMSSW Patches

Before you apply any patches, make sure you have your CMS environment set up correctly. From the CMSSW_3_8_x directory, do:


Now, apply patches and build the new code:

addpkg IOPool/Input
addpkg IOPool/TFileAdaptor
addpkg FWCore/Sources
addpkg FWCore/Services
addpkg FWCore/Catalog
pushd src/FWCore/Catalog
/usr/bin/curl -k | patch -p0
pushd src/FWCore/Services
/usr/bin/curl -k | patch -p0
pushd src/IOPool/Input
/usr/bin/curl -k | patch -p0
scram b -j4 USER_CXXFLAGS="-g"
It might take 3-5 minutes depending on the speed of your computer.

Add the xrootd service to the CMSSW run

Assuming that your site-local-config.xml event-data stanza looks like this:
      <catalog url="trivialcatalog_file://opt/osg/app/cmssoft/cms/SITECONF/local/PhEDEx/storage.xml?protocol=direct"/>
change it to the following:
      <catalog url="trivialcatalog_file://opt/osg/app/cmssoft/cms/SITECONF/local/PhEDEx/storage.xml?protocol=direct"/>
      <catalog url="trivialcatalog_file://opt/osg/app/cmssoft/cms/SITECONF/local/PhEDEx/storage.xml?protocol=xrootd"/>

where the xrootd protocol points to the xrootd redirector of your choice. If you want to use the global redirector, you would add the following line to your storage.xml file:

  <lfn-to-pfn protocol="xrootd" destination-match=".*" path-match="/+store/(.*)" result="root://$1"/>

You can run CMSSW as normal; whenever CMSSW runs into a file it can't open, it will start using the CMS Data Access Testbed.

Topic attachments
ISorted ascending Attachment History Action Size Date Who Comment
Unknown file formatpatch fwcore_catalog_fallback.patch r2 r1 manage 8.0 K 2010-07-13 - 21:30 BrianBockelman  
Unknown file formatpatch fwcore_services_fallback.patch r1 manage 2.5 K 2010-07-13 - 04:59 BrianBockelman  
Unknown file formatpatch iopool_input_fallback.patch r1 manage 2.2 K 2010-07-13 - 05:00 BrianBockelman  

This topic: Main > TWikiUsers > BrianBockelman > CmsIOFallback
Topic revision: r3 - 2010-07-13 - BrianBockelman
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