[erlang-questions] supervisor not restarting gen_server

[Per Melin]

On May 6, 2012, at 00:40 , Robert Virding wrote:

>> Since cowboy_sup received an exit signal of 'killed' from
>> cowboy_listener_sup, doesn't that imply that it was (explicitly)
>> killed with exit(Pid, kill)?
> 
> That is most definitely does. And if the supervisor was killed then that would also have killed the gen_server which would not be restarted as there was no supervisor. The question is then why that supervisor was not restarted by cowboy_sup?

I asked myself that too, but are we sure it wasn't? If AD's gen_server was dynamically started (supervisor:start_child/2) as a descendant to cowboy_listener_sup it could not be started again since that information would now be lost. So it's back to your original question; where is that process started?



>>>> 
>>>> I have a gen_server that seems to be crashing for some reason and
>>>> the supservisor is not restarting it.  The child spec is
>>>> one_for_one, permanent and the error log is below.  All i see is
>>>> the crash report but no attempt at a restart.  Is there any way
>>>> to figure out why the supervisor would not restart it?
>>>> 
>>>> 2012-05-02 14:54:28.776 [info]
>>>> <0.889.0>@websocket_pubsubsrv:terminate:198 Shutting down pubsub
>>>> server...
>>>> 2012-05-02 14:54:28.776 [error] <0.882.0> Supervisor cowboy_sup
>>>> had child {cowboy_listener_sup,my_http_listener} started with
>>>> cowboy_listener_sup:start_link(100, cowboy_tcp_transport,
>>>> [{port,8000}], cowboy_http_protocol,
>>>> [{dispatch,[{'_',[{[<<"multiplex">>,'...'],sockjs_cowboy_handler,{service,"/multiplex",sockjs_multiplex,...}},...]}]}])
>>>> at <0.909.0> exit with reason killed in context child_terminated
>>>> 2012-05-02 14:54:28.785 [error] <0.911.0> gen_server <0.911.0>
>>>> terminated with reason: killed
>>>> 2012-05-02 14:54:28.788 [error] <0.911.0> CRASH REPORT Process
>>>> <0.911.0> with 1 neighbours crashed with reason:
>>>> {killed,[{gen_server,terminate,6},{proc_lib,init_p_do_apply,3}]}
>>>> 
>>>> 
>>>> Thanks
>>>> -AD