Commit d6b0c4dda4 changed the built-in default
murmur3_ignore_msb_bits to 12 (from 0) and removed the scylla.yaml default.
Removal of the scylla.yaml default was a mistake for two reasons:
- if someone downgrades a cluster, keeping scylla.yaml derived from the
master branch, they will experience resharding since the built-in default,
which has changed, will take effect. While that scenario is not supported,
it already happened and caused much consternation.
- if, in the future, we wish to change the default, we will cause resharding
again. Embedding the default in scylla.yaml allows us to change the default
for new clusters while allowing upgraded clusters to retain older values.
Therefore, this patch restores murmur3_ignore_msb_bits in scylla.yaml. Future
changes to the configuration item should change both scylla.yaml and the
built-in default.
Message-Id: <20180930090053.21136-1-avi@scylladb.com>