ngx-lua-request-time

It records the lua execution time per request in ngx.ctx, in microsecond.

Check this blog for details:

http://luajit.io/posts/openresty-lua-request-time/

The request time is the sum of the following metrics:

• lua_resume
  • phases
    • REWRITE
    • ACCESS
    • CONTENT
    • BALANCER
• lua_pcall
  • filters
    • header_filter
    • body_filter

It's non-intrusive and zero-cost.

Usage:

NGX_LUA_REQUEST_TIME_VAR_NAME=openresty_request_time_us \
LD_PRELOAD=/opt/ngx-lua-request-time/ngx_lua_request_time.so \
openresty -p $PWD -c nginx.conf

• NGX_LUA_REQUEST_TIME_VAR_NAME: variable name in ngx.ctx.<var>
• LD_PRELOAD: preload the ngx_lua_request_time.so

build

make
# output ngx_lua_request_time.so

demo

Do not use the Alpine docker image, where the musl libc seems not LD_PRELOAD compatible.

• openresty
• apisix