Error: ClassNotFoundException: za.co.absa.abris.avro.read.confluent.SchemaManager about abris

[cerveada]

SchemaManager class should be available inside Abris jar, but it seems in your case s3://bucket/jars/abris.jar doesn't contain it. I don't know why that would happen.

Can you manually open the jar and check the class is there?

[Rap70r]

Hi @cerveada,

I extracted the code and I can see the class in above bath. Could the error be related to something else? Can this be because the library versions are not aligned?

Thank you

[cerveada]

Can you provide the whole exception with a stack trace? Or maybe the whole log of that run? You can upload files and it may help to find the issue here.

[Rap70r]

Hi @cerveada,

Unfortunately, there is not much info in the stack trace:

    INFO Client: 
	 client token: N/A
	 diagnostics: User class threw exception: java.lang.NoClassDefFoundError: za/co/absa/abris/avro/read/confluent/SchemaManager$
	at scala.collection.immutable.List.foreach(List.scala:431)
	at scala.Function0.apply$mcV$sp(Function0.scala:39)
	at scala.Function0.apply$mcV$sp$(Function0.scala:39)
	at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:17)
	at scala.App.$anonfun$main$1$adapted(App.scala:80)
	at scala.collection.immutable.List.foreach(List.scala:431)
	at scala.App.main(App.scala:80)
	at scala.App.main$(App.scala:78)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.apache.spark.deploy.yarn.ApplicationMaster$$anon$2.run(ApplicationMaster.scala:740)
Caused by: java.lang.ClassNotFoundException: za.co.absa.abris.avro.read.confluent.SchemaManager$
	at java.net.URLClassLoader.findClass(URLClassLoader.java:387)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
	... 23 more

[cerveada]

I opened the jar from maven https://mvnrepository.com/artifact/za.co.absa/abris_2.12/6.3.0

za/co/absa/abris/avro/read/confluent % ls
ConfluentConstants$.class
ConfluentConstants.class
SchemaManager.class
SchemaManagerFactory$$anonfun$$nestedInanonfun$getOrCreateRegistryClient$1$1.class
SchemaManagerFactory$.class
SchemaManagerFactory.class

There is no SchemaManager$ class. Only SchemaManager. The $ is important here.

In Scala there can be class and object both having the same name. In Java this is not possible so when compiling the object names have the $ added at the end.

In Abris SchemaManager object was last present in version 3.2
https://github.com/AbsaOSS/ABRiS/blob/branch-3.2/src/main/scala/za/co/absa/abris/avro/read/confluent/SchemaManager.scala
In newer version it was removed.

So it looks like your code is using the SchemaManager object somewhere and that is causing the issue.

[Rap70r]

Hi @cerveada,

Oh wow, I thought I saw it when I extracted the code. Hmm...
My code does indeed uses that class. Not sure why the class was removed. However, when I check the path under master branch I do see it:

https://github.com/AbsaOSS/ABRiS/blob/master/src/main/scala/za/co/absa/abris/avro/read/confluent/SchemaManager.scala

Isn't that the same one? Or does it get excluded from the library?

Thank you

[cerveada]

As I was trying to explain in the previous message, there are two classes:

SchemaManager.class for SchemaManager scala class
SchemaManager$.class for SchemaManager scala object

The object was removed in Abris 4.

when I check the path under master branch I do see it:
https://github.com/AbsaOSS/ABRiS/blob/master/src/main/scala/za/co/absa/abris/avro/read/confluent/SchemaManager.scala

That is the scala class, but you can see that in that file there is no scala object defined.

This may explain better what object I am talking about:
https://docs.scala-lang.org/overviews/scala-book/companion-objects.html