Porting LCG to IA64 Andreas Unterkircher CERN openlab May 2004

What is LCG ? The goal of the LCG project is to prototype and deploy the computing environment for the LHC experiments. LCG hardly develops software but gathers it from different sources. May 2004 Andreas Unterkircher

LCG code VDT: Globus, Condor(-G), MyProxy EDG: WP1, WP2 DataTAG: GLUE, GridICE LCG: GFAL, lcg-BDII, experiments SW DESY/FNAL: dCache External: ant, tomcat,… May 2004 Andreas Unterkircher

LCG build model Check out from source CVS: EDG software LCG specific code Everything else is “external”. A “build machine” automatically does the build after the checkout. May 2004 Andreas Unterkircher

LCG build model Supports only RedHat 7.3. Sources for “external” packages are not under direct control of LCG. Binaries are distributed as rpms and grouped according to functionality. A new LCG release = a new tag. May 2004 Andreas Unterkircher

Installation of LCG Installation and configuration fully automated by using LCFGng. Manual installation is quite complicated Quote from EDG Installation Guide : “…manual configuration of the services without the benefit of the LCFG configuration components is extremely difficult (…) for now, using this method is strongly discouraged.” May 2004 Andreas Unterkircher

Consequences for IA64 We have to rebuild everything from scratch. LCFG is not available for IA64 thus we have to install and configure everything manually. May 2004 Andreas Unterkircher

Our strategy Initially only port a “minimal grid node”. Demonstrate that such an IA64 node is actually working. Try to get IA64 specific changes into the CVS code repository. Help with porting experiments software. Port more of LCG to IA64 if needed. Make IA64 a fully supported LCG platform. May 2004 Andreas Unterkircher

Porting to IA64 Initially port the code necessary for a Worker Node and a Compute Element. Try to reproduce the x86 rpms provided by LCG as close as possible. May 2004 Andreas Unterkircher

Timeline Started in late summer 2003. End 2003: first “release” of WN and CE rpms. Beginning of 2004: first test installation. February 2004: integration of IA64 CE and WN into the EIS testbed. 16. February 2004: first Grid job submitted to IA64. May 2004 Andreas Unterkircher

Porting obstacles Sources are difficult to find. Complicated dependencies. Documentation is scarce and knowledge is spread amongst different groups. EDG initially has not been targeted for porting. Reverse engineering of build procedures is extremely time consuming. May 2004 Andreas Unterkircher

Porting observations Most of the problems encountered are due to build or configuration issues. The code itself is mostly “IA64 ready”. Different languages: C, C++, Java, Perl, Python, Swig Keeping track with new LCG tags is difficult for us. Thus getting the IA64 extensions into the CVS tree is essential. May 2004 Andreas Unterkircher

Manual installation Many configuration files. Startup scripts are complicated and interleaved. Had to “debug” scripts in order to get them working. LCG is working on better documentation. May 2004 Andreas Unterkircher

Achievements so far VDT will start to release an IA64 distribution from the next release onwards. IA64 specific changes get into the EDG CVS tree. Systematic recording of source locations resp. gathering of source files. Some tests of the IA64 Grid node have been conducted and so far there seem to be no problems. May 2004 Andreas Unterkircher

Future directions The new tag should be IA64 ready soon and be deployed at HP Puerto Rico. Recompiling new tags on IA64 will get faster and faster. LCG is preparing for a new RedHat version – we will follow this direction on IA64. May 2004 Andreas Unterkircher

Future directions We think about automated installation and configuration both with quattor and SmartFrog. Performance comparisons of LCG on x86 and IA64 could be interesting. Already end of this year LCG software could change significantly – hopefully porting to IA64 will then be easier. May 2004 Andreas Unterkircher