Prometheus 1.1.0 Tomcat Metrics return NaN when running on docker container with port 80

[Diệu Nguyễn Hoàng]

Hi all,

When I running a Spring Boot application on docker with port 80, all other metrics fine except:

tomcat_threads_current_threads{name="http-nio-80",} NaN

tomcat_threads_config_max_threads{name="http-nio-80",} NaN
tomcat_threads_busy_threads{name="http-nio-80",} NaN

But the value back to normal when using another port.
tomcat_threads_current_threads{name="http-nio-8080",} 10.0

But all of them was good on version 1.0.3.