LCG Computing Element (lcg CE)

Functional description

LCG CE is a native computing resource access service with Globus Gatekeeper. LCG has modified some of its component to improve its performance like job manager.

Daemons running

• globus-gatekeeper - must be started
• globus-gridftp - must be started
• globus-job-manager-marshal - must be started
• globus-gass-cache-marshal - should be started, but the client is able to work in fall-back mode with stopped daemon
• globus-gma - must be started if GLOBUS_GMA is enabled in site's config

Init scripts and options (start|stop|restart|reload|...)

• globus-job-manager-marshal, globus-gass-cache-marshal and globus-gma scripts support 'reload' action to send a SIGHUP to a daemon.

Configuration files location with example or template

• /opt/globus/etc/globus-gass-cache-marshal.conf, /opt/globus/etc/globus-job-manager-marshal.conf
• logf (srting) - location of the log file (default is relative to GLOBUS_LOCATION)
• maxproc (numeric) - maximum number of parallel requests [this is the most useful variable for tuning] (5 by default)
• rrobin (numeric) - enables round-robin queue mode for users(1) or groups (2) (disabled (0) by default)
• tick (numeric) - hung child processes are killed every this number of seconds (if no other events are happening) (300 by default).
• reqtout (numeric) - client should send a complete request in this number of seconds after connection (10 by default)
• proctout (numeric) - each request (child process) is allowed to run this number of seconds (600 by default)
• reqlimit (numeric) - maximum size of a request in bytes (16384 by default). One should increase this limit if environment is very large.
• window (numeric) - data block for recv/send in bytes, probably should never be changed (default value is 4096 (x86 page size)).
• debug (numeric) - debug level. There are three of them: 0 - only warnings (default), 1 - all messages, 2 - stderr is being redirected to the log file (bad for log parsers, but good for catching problems in perl jobmanagers)
• All parameters (except debug 1 -> 2) could be changed online (modify config file and sent a sighup), both daemons create pidfiles in /var/run/ but their location is not configurable.

Logfile locations (and management) and other useful audit information

• /opt/globus/var/log/*.log - configurable with logf option above.
• /var/log/globus-gridftp.log
• /var/log/globus-gatekeeper.log
• /var/log/message
• /opt/edg/var/gatekeeper/

Open ports

Possible unit test of the service

Where is service state held (and can it be rebuilt)

Cron jobs

• /etc/cron.d/

and are:

• bdii-proxy
• edg-mkgridmap
• lcg-expiregridmapdir
• cleanup-grid-accounts
• edg-pbs-knownhosts
• cleanup-job-records
• edg-pbs-shostsequiv
• edg-apel-pbs-parser
• fetch-crl

How the site admin can block a specific user

Utility scripts

Location of reference documentation for users

• gLite 3.1 documentation

Location of reference documentation for administrators

• gLite 3.1 documentation