Difference: SystemAdministratorGuideForEMI1 (40 vs. 41)

Revision 412011-10-29 - MassimoSgaravatto

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META TOPICPARENT name="SystemAdministratorDocumentation"

System Administrator Guide for CREAM for EMI-1 release

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1 Installation and Configuration

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1 Installation and Configurationf

 

0.1 Prerequisites

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  To allow a parallelism when interacting with the batch system, in particular to have a good throughput when submitting jobs to the batch system, CREAM can run multiple BLAH instances. A new instance is created whenever needed, till the maximum number defined in the etc/glite-ce-cream/cream-config.xml configuration file is reached. The relevant attribute is cream_concurrency_level. The default value is 50.
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0.0.0.1 Tune the BLAH BUpdater polling frequency

If the new BLAH Blparser is used (click here for instructions to check if you are using the old or the new blparser) the parameter bupdater_loop_interval attribute in /etc/blah.config defines how often the batch system is queried to check the status of the jobs. If a low value is used, job status changes are detected promptly, but this also means that several batch system queries are done, and this can cause a high load.

With yaim-cream-ce v >= 4.2.2-1, this parameter is configurable via yaim: the relevant yaim variable is BUPDATER_LOOP_INTERVAL which has 30 (secs) as default value.

With yaim-cream-ce v. < 4.2.2-1, this parameter is not configurable via yaim, and therefore it is needed to manually edit the blah configuration file, otherwise the default value (5 s.) is used. After having set this value in the blah configuration file it is necessary:

  • to stop tomcat: service tomcat5 stop
  • to restart the blparser: /etc/init.d/glite-ce-blahparser restart
  • to start tomcat: service tomcat5 start

In particular for LSF it is necessary that this value is not too low. As a general rule it is recommended to set it to 1.5 * (average of time needed to execute bhist -u all -d -l -n 1).

 

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