servlet not getting invoked

Question

I develop simple servlet in Liferay. I see that its getting initialised ( verified by putting System.out in init() method). But when I post some data to the servlet, Its not getting invoked. How can this be debugged or what I need to add it to get it working.

Made servlet entry file : webapps/ROOT/WEB-INF/web.xml, The liferay has other custom webapps working.

   .....
   <servlet>
       <servlet-name>HealthCheckServelet</servlet-name>
       <servlet-class>com.test.HealthCheck</servlet-class>
       <load-on-startup>1</load-on-startup>
   </servlet>
   <servlet-mapping>
       <servlet-name>HealthCheckServelet</servlet-name>
       <url-pattern>/health-check/*</url-pattern>
   </servlet-mapping>
   .......

The servlet is invoked using HTTP GET http://host-ip/health-check/temperature

Answer 1

The invoking URL suggests that the health check has nothing to do with Liferay, rather with the server that your application is running on. I'd implement this in a separate web application totally independent of Liferay and deploy it on the same application server. This way you don't need to mess with Liferay's web.xml (which would need to be migrated should you update Liferay) and still gives you the same benefits. If you still need Liferay information in your health check, just use the API to get the data you need. Again - you gain far better maintainability.

The side effect of this is that you gain easy debugging in a tiny web application that doesn't need Liferay running. It'll be easy to post a MCVE here with all the code you're seeking advice on.

Also, by running outside of Liferay, you're not subject to any of the servlet filters that Liferay will apply to the request handling - your request might get caught in them already, who knows. It's a way too complicated solution for a simple problem.