Ok, the NoClassDefFound can sometimes be caused by a driver version mismatch or an invalid path, so I would double check the version and folder location as per this thread.
Otherwise, depending on the version of Elasticsearch you are looking to ingest into I can think of a couple of other options:
- There is a beta of the MongoDB client connector that can be used with Python available as of 8.4 that you could leverage which is available on the free tier.
- Do you have a license for Elastic at all and running 8.5 or later? Another option would be to take a look at the MongoDB native connector, but it is a feature available for platinum license and above.
- Exec input plugin which is discussed in this old thread.
Do let us know how you get on!