When using an UDAF in a VDB, the required JAVA_CLASS and JAVA_METHOD are specified in the VDB.
When for some reason the JAVA_CLASS or JAVA_METHOD do not exist in the library, the message from the system is quite imperceptible.
In the following log excerpt, GlobalTitleRangeCheck class does not exist in the jar rangecreator. The model name that is defining the VIRTUAL FUNCTION is RangeGroupConcat. The VDB name is CountryServiceListVDB.
As observed from the log excerpt, the only possible hint to know what the problem is with the FAILED deploy might be:
model "RangeGroupConcat" Using translator null and connection null to load metadata.
But this is a normal logging message that doesn't have nothing to do with the real problem.
When putting the entire system logging ALL levels, then is easy to see what the problem is:
Here it is observable what the real problem is:
No local specification found for class com.truphone.teiid.udaf.GlobalTitleRangeCheck in Module "mnom.rangecreator:main"
So, to avoid unnecessarily losing time to investigate what the problem is, the message that is currently in TRACE level should be in, at least, INFO level.