Creating a repository on Mesh always assigns the same partition ID

Issue Summary

This is reproducible on Data Center: yes

When starting out with an empty Bitbucket Mesh cluster and a repository is created, it is always assigned the same partition ID.

If you already created a number of repositories (more than ~30) on an unaffected version, you are not affected by this bug.

Steps to Reproduce

1. Start out with an empty Bitbucket Mesh cluster
2. Create a repository on Mesh

Expected Results

The repository is assigned a random partition ID.

Actual Results

Newly created repositories are assigned a random, populated partition. No empty partitions are considered. This means that starting from an empty Mesh cluster, all repositories are assigned the same partition ID.

This will lock all created repositories to a specific set of Mesh nodes. Adding additional Mesh nodes does not spread the load.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available