Earthworm Modules:
Startstop Overview

(last revised Apr 24, 2015)

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 Linux, SUN Solaris and Windows NT operating systems.

For startstop to work, it must know about the Earthworm environment. This is typically done by setting the environment variables within the environment/ew_* file specific to your platform, and then sourcing that file, or executing the cmd if you're on Windows. Startstop typically reads its configuration file from the EW_PARAMS directory (as defined in your environment) 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. Note that each module and each ring specified must be definined within earthworm.d or earthworm_global.d, which should be in the EW_PARAMS directory. The system continues to run until "quit<cr>" 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.

Note that two copies of startstop pointing at the same startstop *d file are not allowed to run simultaneously. The second one started will fail and quit. (If you really want to do this for some reason, you'd need to make sure that you use all different rings in the second version, different ports for the modules, and a different startstop*d file, specified as a parameter when starting startstop.)

If the user presses the "Enter" key while the startstop command window is selected, or enters the command "status", startstop will print a status table showing various statistics for each module, including whether it is dead or alive. If a module is dead because it could not be started (for example, the executable's name were mistyped so the executable could not be found), it will be reported as NoExec.

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:

Interactive commands:

Startstop will repond to the following commands from the status console window. There are similar command line versions of each command as well.

Solaris, Linux, Mac OS X versions:


Windows, Windows Service version: