Improve analysis of Tomcat connector start failures by using new throwOnFailure attribute

[wilkinsona]

Tomcat 9 now includes an attribute that means that a connector start failure will result in an exception being thrown. We should catch that exception and use it to throw a specific exception that can then be analysed.

[mbhave]

@wilkinsona I wasn't able to get hold of the bind exception even after setting throwOnFailure to true. For the primary connector, we set bindOnInit to false so something like a BindException will be thrown on start instead of init. However, even though connector.start() throws a LifecycleException when the flag is set, it is caught and logged by addConnector.

[wilkinsona]

That's a shame. I should have looked more closely at the change when it was made. I've opened another Tomcat issue to see if a change can be made for this scenario as well.

[wilkinsona]

https://bz.apache.org/bugzilla/show_bug.cgi?id=63358 has been fixed and will be included in Tomcat 9.0.20.

[wilkinsona]

This is no longer blocked as Tomcat 9.0.20 has been released and we have upgraded to it.