Keeping it here so that anyone after me can find these configs easily.

At my job I've been writing a microservice with java with reactive style. I'm also using mongodb with panache. Recently I had a problem where one of my queries were working perfectly from mongo compass but with panache it wasn't working as expected. So I needed to see the query that panache was generating.

The quarkus's official document provides a way to log mongodb query in output. Unfortunately it only works for non reactive java and the guide doesn't properly mention this.

quarkus.log.category."io.quarkus.mongodb.panache.common.runtime".level=DEBUG

At first I thought for some reason maybe my project configuration was wrong or maybe configs were conflicting and that's why it wasn't showing the logs. I never thought what reactive coding was the problem. So I debugged the issue in other ways and found the proper solution for my problem.

After that I got somewhat bothered and kept asking myself why the query logging wasn't working and got frustrated. Then in an eureka moment I looked at the configuration key carefully and I can clearly see that the log was enabling a category io.quarkus.mongodb.panache.common.runtime so I went looking for that package. From my jetbrains IDE I found it and I can clearly see that there is a common.runtime.CommonPanacheQueryImpl and another common.reactive.runtime.CommonReactivePanacheQueryImpl.

So I tried to filter by that category and it worked :)
So the solution is to just enable DEBUG on this category. So add this line to your application.properties.

quarkus.log.category."io.quarkus.mongodb.panache.common.reactive.runtime".level=DEBUG

Now the logging is working

Bonus

While searching I've found another way to enable query logging, but it is logging from the mongodb driver. To enable it just add this to the application.properties

quarkus.log.category."org.mongodb.driver.protocol.command".level=DEBUG

The result looks like this, it also outputs the result from the db.

Just thought that I'd post these configs here as a reference to someone who is doing reactive java with panache. As I've invested one of my weekends figuring this out as well as other things. I'll probably make a longer post on my journey as a Senior Software Engineer to debug a panache capability issue and how a junior might navigate these and what were my step by step thought process during this.

I've learned all these because I kept asking myself "why wouldn't it work?" and it kept bothering me.

References

1. My own notes
2. Quarkus docs
3. A github discussion