Cray Lightweight Log Manager (LLM)

The Cray Lightweight Log Manager (LLM) is the log infrastructure for Cray systems and must be enabled for systems to successfully log events. At a high level, a library is used to deliver messages to rsyslog using the RFC 5424 protocol; rsyslog transports those messages to the SMW and places the messages into log files.

The LLM system relies on the sessionid that is generated by xtbootsys. Therefore, systems must always be booted using xtbootsys. If the site has multi-part boot procedures or uses manual procedures, have the process started by an xtbootsys session. That session can be effectively empty; it is needed only to initiate a boot sessionid. Subsequent xtbootsys calls can then use --session last or manual processes.

By default, LLM has a log trimming mechanism enabled called xttrim.

Important: Do not use the xtgetsyslog command because it is not compatible with LLM. For additional information, see Manage Log Files Using CLE and HSS Commands.

To configure the LLM, use cfgset update to update the cray_logging configuration service in the global or CLE config set.

For further information, see the intro_LLM(8) and intro_LLM_logfiles(5) man pages.