---
features:
  - The Carbonara based storage engine has been updated and greatly improved.
    It now features fast write for Ceph (no change for file and Swift based
    drivers) by using an append method.
    It also features on the fly data compression (using LZ4) of the aggregated
    time serie, reducing the data space usage by at least 50 %.
upgrade:
  - gnocchi-upgrade must be run before running the new version of
    gnocchi-metric and the HTTP REST API in order to upgrade from version 2 of
    the Carbonara storage engine to version 3. It will read all metrics and
    convert them to new version 3 serialization format (compressing the data),
    which might take some time.