I use jetty in version 9.4.6.v20170531, and faced the ClassNotFoundException: ch.qos.logback.access.jetty.RequestLogImpl when I follow the steps.

Please modify the document to correct the directory which logback-core-VERSION.jar and logback-access-VERSION.jar would be located.

https://logback.qos.ch/access.html#jetty

In the document above, it shows both jar file should be in $JETTY_HOME/lib/ but it should be in $JETTY_HOME/lib/ext/ actually.