1) does the log service of a corresponding long run service goes down when the long run service is made down using some s6 commands? (like s6-rc -d change <long run service name>
No, because as Crest says, a producer foo depends on a consumer foo-log,
not the other way around, so bringing up foo also forces foo-log to be up, but bringing it down does not force foo-log to be down. (Bringing down foo-log, however, forces foo to be down.) s6-rc provides you with a natural solution to this, though: in your foo-log definition directory, you can define a "pipeline-name" file: that will automatically create a bundle containing foo and foo-log, named after the contents of pipeline-name. If you do, for instance: echo foo-pipeline > foo-log/pipeline-name and recompile your database, then s6-rc -u change foo-pipeline will always bring up foo *and* foo-log, and s6-rc -d change foo-pipeline will always bring down foo *and* foo-log.
2) Shall we use s6-log for one shot services too?
s6-log is a long-lived process, designed to log the output from long-lived process. It doesn't really make sense to use a dedicated logger for a oneshot. What s6-rc does is that the output from all your oneshots is sent to the catch-all logger, i.e. the place where the supervision tree sends its output by default. If you are using a s6-linux-init installation, or similar, chances are that this catch-all log is itself handled by a s6-log process. Check your /run/uncaught-logs directory.
3) is there any command-line option we can provide to s6-log for stopping the running s6-log?
To stop a running s6-log process, simply send it a SIGTERM. If the s6-log process you want to stop is supervised, the command you want is probably s6-svc -d /run/service/foo-log Be aware, though, that if you stop a logger without stopping the corresponding service, funny things can happen when the logging pipe fills up: depending on how the service is written, it may lose logs, or it may hang, or it may die. You should probably never have to stop a logging process without bringing down the entire pipeline that leads to it. -- Laurent