Massive insertion (multiple threads/buckets + non unique index) leads to timeout/excessive retries #2258
Description
From Discord Channel (user Kolja):
I wrote a small stress test (in Kotlin though) that reproduces the problem a 100% of the time on my machine: https://gist.github.com/koljakube/73062a48afe29ea6fff8d6a55b2a3d2d