## Migrating from 0.7.x to 0.8

0.8 is our first (and hopefully last) release with a non-backwards-compatible wire protocol, ZooKeeper layout, and on-disk data format. This was a chance for us to clean up a lot of cruft and start fresh. This means performing a no-downtime upgrade is more painful than normal—you cannot just swap in the new code in-place.

### Migration Steps

1. Setup a new cluster running 0.8.
2. Use the 0.7 to 0.8 migration tool to mirror data from the 0.7 cluster into the 0.8 cluster.
3. When the 0.8 cluster is fully caught up, redeploy all data consumers running the 0.8 client and reading from the 0.8 cluster.
4. Finally migrate all 0.7 producers to 0.8 client publishing data to the 0.8 cluster.
5. Decommission the 0.7 cluster.
6. Drink.