The master daemon runs on every machine in the LoadLeveler cluster, except the submit-only machine. The real and effective user ID
The master daemon determines whether to start any other daemons by checking the START_DAEMONS keyword in the global or local configuration file. If the keyword is set to true, the daemons are started. If the keyword is set to false, the master daemon terminates and generates a message.
On the machine designated as the central manager, the master runs the negotiator daemon. The master also controls the central manager backup function. The negotiator runs on either the primary or an alternate central manager. If a central manager failure is detected, one of the alternate central managers becomes the primary central manager by starting the negotiator.
The master daemon starts and if necessary, restarts all the LoadLeveler daemons that the machine it resides on is configured to run. As part of its startup procedure, this daemon executes the .llrc file (a dummy file is provided in the bin subdirectory of the release directory). You can use this script to customize your local configuration file, specifying what particular data is stored locally. This daemon also runs the kbdd daemon, which monitors keyboard and mouse activity.
When the master daemon detects a failure on one of the daemons that it is monitoring, it attempts to restart it. Because this daemon recognizes that certain situations may prevent a daemon from running, it limits its restart attempts to the number defined for the RESTARTS_PER_HOUR keyword in the configuration file. If this limit is exceeded, the master aborts and all daemons are killed.
When a daemon must be restarted, the master sends mail to the administrator(s) identified by the LOADL_ADMIN keyword in the configuration file. The mail contains the name of the failing daemon, its termination status, and a section of the daemon's most recent log file. If the master aborts after exceeding RESTARTS_PER_HOUR, it will also send that mail before exiting.
The master daemon may perform the following actions in response to an llctl command: