MythBusters Impala edition "Impala udf functions runs even after jar is removed" BUSTED

While I was working on a Java Impala UDF, a colleague pointed me to: Impala udf functions runs even after jar is removed

Thought that should give it a try - it might happen that all my work will be useless because of that. I prepared two jar files with the same class names (but different implementations!). UDF signatures were the same. The scenario was as follows:

1. Create a function from first jar in schema A.
2. Execute query with that function.
3. Drop function.
4. Try to execute query with function (failed - as expected).
5. Replace the first UDF jar file in HDFS with second implementation.
6. Create a function from the same path in HDFS in schema A (with the same UDF signature!).
7. Execute query with that function - query worked and second version of code was invoked.

No signs of problems described in the original post. Version of Imapala used: 1.4.1. I’ve also tried a different scenario:

• two jars with the same name (but different paths in HDFS)
• same class names
• two different implementattions
• each implementation registered in different schema

Unfortunately - in this case it also worked fine ;)