Creating alarms for segfaults

[prymitive]

I wanted to use alarm subsystem to notify me in case of any segfault, but log-alarm handles only single line at a time. Could we also have segfault-alarm = alarm_handler that would fire when any worker segfaults and pass whole backtrace to the alarm handler?

[unbit]

You can trigger alarms in your code with

void uwsgi_alarm_run(struct uwsgi_alarm_instance uai, char msg, size_t len);

to get a uwsgi_alarm_instance pointer you can use:

struct uwsgi_alarm_instance uwsgi_alarm_get_instance(char name);

where name is the name of the alarm instance

the log-alarm subsystem simply trigger that for every logline that matches. You can add more cases in which to put that

[prymitive]

Thanks, I'll try to implement alarms for segfaults and harakiri in few days.

[unbit]

Have you already started that ? I would like to clean the api a bit for making the triggering of alarms from processes other than the master easier.

[prymitive]

No and I won't have time for it this week, go ahead with those changes.

[prymitive]

Are those API changes done? I don't see any.

[unbit]

still not. Need to fix 3 areas in 1.9 before (ruby fibers, fastcgi and mongrel2 support). Hope to work on that tomorrow

[prymitive]

Ok, no rush, just let me know

[unbit]

Ok, the api function is ready:

uwsgi_alarm_trigger(char alarm_name, char message, size_t message_size);

you can call it in all of the processes (or from apps, using uwsgi.alarm(name, msg))

I do not know how you intend to map it to the SEGV handler, maybe you have to combine the whole backtrace output to a single memory buffer...

[prymitive]

I do not know how you intend to map it to the SEGV handler, maybe you have to combine the whole backtrace output to a single memory buffer...

I have no idea either, but not knowing before and knowing it once You're done is part of the fun ;)

[prymitive]

BTW it looks like I might have busy week so I don't know if I'll be able to look into it until next weekend

[prymitive]

Please review this patch It will break on each request since it will divide by zero (for testing).

./uwsgi --http :8080 --wsgi-file tests/staticfile.py --alarm "mailme cmd:mail -s 'uWSGI alarm' -r 'uwsgi@localhost' me@domain.com" --segfault-alarm mailme

and then just curl localhost:8000

[prymitive]

Any chance we could finish this one before 1.9?

[unbit]

yes for sure, i need to make a couple of corner-case-fixes and should be complete

[prymitive]

It would be real handy if we could push this forward in not so distant future.