wsgi daemon mode

I run my stateless flask apps with mod_wsgi/apache using daemon mode like:

WSGIDaemonProcess foo-services python-home=/opt/my_org/foo-services/_env processes=8 threads=48 maximum-requests=10000 display-name=%{GROUP}
WSGIApplicationGroup %{GLOBAL}
WSGISocketPrefix /var/run/wsgi


Alias /image-services "/opt/my_org/foo-services/wsgi.py"
<Location "/for-services">
SetHandler wsgi-script
Options +ExecCGI
FileETag None
ExpiresActive On
ExpiresDefault "access plus 1 year"
WSGIProcessGroup image-services
</Location>

Which means when a request gets to the service it could be hitting 1 of 8 daemon processes each of which have their own memory in isolation of the others. Does the metrics endpoint store the prometheus data in a way that is shared across these daemons?

I can create some tests to verify if thats the case or not, just curious if the answer is already known.

Thanks, Thatcher

[rycus86]

Oh, so sorry I forgot to mention that! 😕 Yes, you do need that, maybe I should make that fail more aggressively, currently it’s only checked in a few places, and obviously your code path didn’t run into it. https://github.com/rycus86/prometheus_flask_exporter/blob/master/prometheus_flask_exporter/multiprocess.py#L12

Glad you managed to work it out! 👍

[torquerrr]

@rycus86 Thank you for your help, I will try this approach and return with results 😃 Yes, I will try to prepare such example. I want to reproduce that locally because I see this issue on Kubernetes pod only (