Logback 1.3.0 and Jetty 9.4.50 having the compatibility issues

Question

Logaback version 1.3.0 uses Javax-Servlet version 4.0.1.

In the same application, I am using Jetty 9.4.50, which uses javax-servlet 3.1.0.

When I load logback.xml locally, my application works successfully.

If I start the application through the Jetty server, no logs are generated

( logback.xml file cannot be loaded by the Jetty server).

According to my understanding, Logback and Jetty have the same Javax-servlet version

Could you please tell me why my logs are not generated?

Answer 1

First, and most important, Jetty 9.x is now at End of Community Support.

See announcement at https://github.com/eclipse/jetty.project/issues/7958

You should be using Jetty 10+ now.

For Logback, you cannot use Logback 1.3.x on Jetty 9.x

That's because it requires Servlet 4.0.1, which is available on Jetty 10+ (not Jetty 9)

For Jetty 9.x you should stick with Logback 1.2.x, but that also means you are stuck with all of the Hanging / Blocked Thread / Async / 100% CPU bugs that logback hasn't fixed in Logback 1.2.x (many were fixed in Logback 1.3.x, and a lot more were fixed in Logback 1.4.x).

The breakdown of Logback to Servlet to Jetty

Logback	Servlet	Namespace	Jetty
1.2.x	Servlet 3.1.x	javax.servlet	Jetty 9.x
1.3.x	Servlet 4.0.x	javax.servlet	Jetty 10.x
1.4.x	Servlet 5.0.x	jakarta.servlet	Jetty 11.x