supervise

Section: Maintenance Commands (8)
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NAME

supervise - starts and monitors a service.

SYNOPSIS

supervise s

DESCRIPTION

supervise switches to the directory named s and starts ./run. It restarts ./run if ./run exits. It pauses for a second after starting ./run, so that it does not loop too quickly if ./run exits immediately.

DISABLING A SERVICE AT START

If the file s/down exists, supervise does not start ./run immediately. You can use svc(8) to start ./run and to give other commands to supervise.

SERVICE DEPENDENCIES

The file s/trigger acts as trigger for s depending on s' and is typically considered at start. trigger contains the full path name of a file which is used to check the existance of the dependent process given its pid. Chaining of supervise services is achieved including <path>/s'/supervise/status. Now, the start of service s is delayed for one second until s' is up and running. External services are typically provided via their pid file, ie. /var/run/<daemon>.pid.

STATUS

supervise maintains status information in a binary format inside the directory s/supervise, which must be writable to supervise. The status information can be read by svstat(8).

REQUIREMENTS

supervise may exit immediately after startup if it cannot find the files it needs in s or if another copy of supervise is already running in s. Once supervise is successfully running, it will not exit unless it is killed or specifically asked to exit. You can use svok(8) to check whether supervise is successfully running. You can use svscan(8) to reliably check a collection of supervise processes.

REFERENCES

https://cr.yp.to/daemontools.html, https://github.com/bruceg/daemontools-encore

This document was created by man2html, using the manual pages.
Time: 09:02:16 GMT, June 02, 2026