Runnning gatling-maven-plugin-demo ==> NoClassDefFoundError: ch/qos/logback/core/joran/spi/JoranException

How is one supposed to run simple Maven based simulations? This used to work.

System Info:

I have searched and found no current, similar posts here. I am noticing that although I changed nothing since this last worked in December 2014 (pom is unchanged) the system now seems to need this lass which is found only in logback-core. However, when I run:

mvn dependency:resolve

I see only logback-calssic. By adding logback-core to my pom the dependcy is brought down and I can run my unchanged Gatling simulation. I guess I can chalk this up to a Gatling pom issue? Shouldn’t it have logback-core with it? I don’t need it. But Gatling does, AFAIK.

Hi,

With dependency:resolve, you probably only see the direct dependencies, not the transitive ones (logback-classic depends on logback-core with compile scope).
Try dependency:tree instead.

This is just standard maven transitive dependency mechanism, I have no idea about what you’re doing.
I suspect you either exclude manually some dependencies, or had a broken maven artifact download that you finally managed to start over again.

Just for closure here I wish to state that:

[1] Yes transitive dependencies are an issue - but I think the current Maven/Gatling demo up at https://github.com/gatling/gatling-maven-plugin-demo fails for the same reason - “out of the box”. IMO it should be able to work after cloning, no changes.

[2] I had made no changes on my end and used an earlier Gatling and never saw this issue.

[3] Maybe as you state #1 and #2 are due to a failed Maven download… but given I have deleted my .m2 repoistory during my debugging attempts I arrivedd at the “fix” to include the logback-core from my om and so that issue is now “fixed”. Probably I have an issue with my nexus maven proxy just for this, and only this artifact or … something else.

Thanks for your reply.

Just for closure here I wish to state that:

[1] Yes transitive dependencies are an issue - but I think the current
Maven/Gatling demo up at
https://github.com/gatling/gatling-maven-plugin-demo fails for the same
reason - "out of the box". IMO it should be able to work after cloning, no
changes.

Absolutely.
I just removed my local maven repo, cloned, ran "mvn gatling:execute
-Dgatling.simulationClass=computerdatabase.BasicSimulation" and it worked
out of the bow as expected.

[2] I had made no changes on my end and used an earlier Gatling and never
saw this issue.

Yep, but we upgraded version of logback, so you had to download the new
versions.

[3] Maybe as you state #1 and #2 are due to a failed Maven download... but
given I have deleted my .m2 repoistory during my debugging attempts I
arrivedd at the "fix" to include the logback-core from my om and so that
issue is now "fixed". Probably I have an issue with my nexus maven proxy
just for this, and only this artifact or ... something else.

Yes, it could be that some file is corrupted in your proxy. Instead of the
logback-core jar, it could be the logback-classic pom, making maven enable
to discover the transitive deps. Just guessing.