Spring AOP conflicting with Dynatrace instrumentation
Has anyone else experienced this?
We're using Spring 3.2.8 and DT 6.0
It looks like Spring AOP complains when DT instruments a class that Spring AOP has instrumented already. Upon starting the Tomcat JVM, the error looks like this:
nested exception is java.lang.VerifyError: (class: Whatever$$EnhancerBySpringCGLIB$$1e40391d, method: doFilter signature: (Ljavax/servlet/ServletRequest;Ljavax/servlet/ServletResponse;Ljavax/servlet/FilterChain;)V) Inconsistent stack height 0 != 1
Basically, DT instruments "Whatever$$EnhancerBySpringCGLIB$$1e40391d" after Spring AOP has instrumented it.
One should be able to reproduce it by using:
<aop:scoped-proxy/>
in the bean declaration. This will instruct Spring to instrument the class. And it will blow up when DT attempts to re-instrument it.
Creating an exclusion did not work, though I am not sure why. Here's how I attempted to do that:
- Create a new Sensor group called 'Ignore'.
- Add class with pattern $$EnhancerBySpringCGLIB$$ and set the matching to Contains.
- Add Global Exclude method rule.
- Add 'Ignore' sensor placement to agent group.
- Restart JVM. Still the error persists
Roy,
A global exclude does not work here. You have to exclude it at agent level or at sensor pack level (servlet and UEM). This has been fixed with 6.1
Regards
Harry
Thanks, I realize that now. I have been working with Joe Hoffman on the issue. He has created an exclude at the sensor pack level for Servlet for my dT 6.0 instance (on the cloud here). However, still the error persists. We are still not sure why that is the case.
I even tried un-placing the Servlet sensor pack, thinking that it would skip instrumenting all classes it is 'responsible' for (not sure how this 'scope of responsibility' is determined - by Java package name??), just to see if it makes a difference, but the error still persists. Probably I'm not understanding the role of sensor packs with respect to instrumentation.
Roy,
Did you check the UEM sensor as well? This sensor does also Servlet transformation, and the classes must be excluded the same way.
Harry
Good catch Harold, We will try the UEM sensor.
Looks like that did the trick, thanks guys!
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