[erlang-questions] Problems stop/attach a release

[Fred Hebert]

On 03/21, Khitai Pang wrote:
>No, I have no erlang:set_cookie/2 in my code.  Now the app gets cookie 
>from vm.args (-setcookie).
>
>I do have another problem though, if I remove -setcookie from the 
>vm.args and rebuild the release, the built release can't start.  I 
>don't understand why.
>
Relx uses nodetools, and nodetools seems to want a cookie real bad to 
avoid different apps communicating each other accidentally.

If the issue isn't related to cookies, it may be due to the app 
hierarchy itself.

In some cases, applications do not get proper dependency lists (which 
app depends on which apps), or omit to include apps like 'stdlib' and 
'kernel'.

In such cases, what may happen is that when shutting down, the Erlang 
node tears down 'kernel' or 'stdlib' before some other running 
application. Then the node is stuck in that mode where it is technically 
still running, but no functions may be called and it just doesn't ever 
shut down. When you get to that point, forcefully killing the node is 
the only thing I know how to make work.

The sad part is that any single dependency you include in your release 
may be to blame for this.

No idea if this is specifically your problem, but it's one I've seen 
before.