restarting child processes

Samuel Rivas <>
Thu Oct 20 08:28:09 CEST 2005


Lennart Ohman wrote:
> the childprocess (or worker) crashes in its init-phase. You
> can se this by examining the Context field in the supervisor
> report (start_error). The supervisor will then consider itself
> to be a failure and crash in its own initphase.
> As a note, your child is actually not a proper OTP process either,
> or to put it in a more polite way :-) one can say that you have
> choose to role-your-own by not using for instance the gen_server
> behaviour.

  Well, the serious problem is not not using the gen_server behaviour,
a supervisor can start other processes if you follow the instructions in
the manual. The main issue is that start_child() is not starting any
process at all.

  So, paraphrasing the manual:

   "The start function must create and link to the child process, and
  should return {ok,Child} or {ok,Child,Info} where Child is the pid of
  the child process and Info an arbitrary term which is ignored by the
  supervisor."

  Whereas start_child simply goes into a receive block and crashes after
750 ms. Thus, it is not the child process who is crashing but the
supervisor process itself.

  Regards.
-- 
	Samuel



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