Hello,

So after messing with the data that you sent us, I was not able to reproduce any keys coming back to life, even after the GC period expires.

What I did step by step was:
Checked the sstable2json output which showed key with the value [].
Then I waited GCseconds.
I ran a repair.
Then waited another GCseconds.
Now sstable2json shows another key, unrelated to the original key. We've logger that error and it is now up on our issue tracker, but I still saw no zombies.

By running these steps alone, do the zombies keys still come back?

We think there might be a logical error when a delete is called. Could you add asserts to make sure the values you are getting around your calls are correct? Do let us know if any of those asserts fail.

Thanks,
Joaquin