Earthworm Modules:
Startstop Overview

(last revised 26 May, 2006)

This program starts and stops an Earthworm system. It reads its configuration file which specifies the message transport rings to be created, which modules are to be run, and the names of the parameter files each module is to read on startup. The program is system dependent, and there are versions available for the SUN Solaris and Windows NT operating systems.

Startstop reads its configuration file and creates the specified rings. It then starts each module as a child process, passing its configuration file name, and any other parameters as its command line paramters (argv, argc). Each module (child process) is started with the priority indicated in startstop.d. The system continues to run until "quit" is typed in startstop's command window. Startstop then sets a terminate flag in each transport ring. Each well-behaved module (child process) should periodically check for the terminate flag, and exit gracefully if is set.

If the user presses the "Enter" key while the startstop command window is selected, startstop will print a status table showing various statistics for each module, including whether it is dead or alive.

Startstop will also react to 'restart' messages from statmgr. This is part of a scheme wich works as follows: A module may have the token "restartMe" it its .desc file (the file given to statmgr, which tells it how to process exception conditions from that module). If its heartbeat ceases, statmgr will send a restart request to startstop. Startstop will then kill the offending module, and restart it with the same arguments as it did at startup time. There are some system specific features, listed below:

Solaris, Linux versions:

Windows, Windows Service version: