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Name


PCT -- Process Control Thread

Synopsis


pct [-nid num -pid num ] [-D] [-S [1|0]] [-L [1|0]] [-daemon]

Description


The PCT (Process Control Thread) is a process running on each compute node of the Cplant. The PCT accepts the parallel application executable image from yod and starts the user process. The PCT can respond to bebopd requests for status information about it's state and about the user process it is hosting.

Options


-nid node-number -pid portal-id
The PCT normally registers with the bebopd managing the virtual machine. If an alternative bebopd is running for test purposes in addition to the regular bebopd, and you wish this PCT to register with the alternative bebopd, then provide the node number and portal ID of that bebopd with these arguments.

-D
This option causes the PCT to output information about what it is doing. Repeating the -D option on the command line increases the amount of information. Normally the information goes to the log file (/var/log/cplant) on the compute node. This can be changed with the -S and -L options.

-daemon
By default the PCT runs as a foreground process. Use -d to run it in the background.

-S [0|1]
The PCT outputs warnings and errors, and, if the -D option is used, status information. The 0 switch turns off all output from the PCT to std err. The 1 switch turns it on. By default, the PCT doe s not write to stderr.

-L [0|1]
The PCT outputs warnings and errors, and, if the -D option is used, status information. The 0 switch turns off all output from the PCT to the log file. The 1 switch turns it on. By default, the PCT does write to log file.

Errors


The PCT reports error conditions in the log file (/var/log/ cplant). It will not exit unless the error makes it impossible for the PCT to do it's job, for example if it has no memory to allocate a por tal. Errors in loading applications are reported back to yod.

Signals


On receiving a SIGUSR1 or SIGUSR2, the PCT will log the rou tine it is in now, what routines it was in most recently, and the state o f the application process it is hosting. It will also display a loop c ounter, which should increment on subsequent displays, indicating whether the PCT is stuck somewhere or has been progressing through it's main service loop. On receiving a SIGHUP, the PCT will close and reopen it's l og file, re-read the site file, and re-read the cplant-host file and send a status update to the bebopd listed there.

Files


/cplant/cplant-host
This file identifies the location of a bebopd daemon.
/etc/local/site
This file defines site specific information that may be required by the bebopd.
/var/log/cplant
This is the log file where Cplant daemons and utilities log status.

See Also


pingd bebopd yod site

Bugs


Let us know if you locate any (cplant-help@cs.sandia.gov).


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