Lua performance

naidilepn · 2019-07-16T23:02:17+00:00

Hi, Following this topic, I made the following stap file, but for some reason thelj_trace_exit it's only called 10 times, after that, is never called aga...

Lua performance

naidilepn

Hi,

I want to check the processing time of my nginx Lua code. But Lua doesn't support milliseconds. Is there a way to check the response time.

Thanks

thibaultcha

Nginx certainly supports milliseconds precision, and so does OpenResty.

See:

https://github.com/openresty/lua-nginx-module#ngxnow
https://github.com/openresty/lua-nginx-module#ngxupdate_time

Don't forget to call ngx.update_time() if your Lua code is not yielding
in between two ngx.now() calls.

Secondly, many Nginx variables expose various underlying timing metrics:

http://nginx.org/en/docs/varindex.html

You can read them in Lua via the ngx.var.VARIABLE API
(https://github.com/openresty/lua-nginx-module#ngxvarvariable).

Finally, there also exist many systemtap scripts developed by OpenResty
to help you measure the performance of your Lua code in other meaningful
manners:

https://github.com/openresty/stapxx

Note that as of today, some of these scripts may not work with the
latest OpenResty releases (contributions welcome).

Best,
Thibault

naidilepn

Thanks. I will check this out