Why is the 2.2.11 release dependent on Couchbase Java SDK 2.2.8 still? I thought the plan was to upgrade the SDK dependency to 2.5.6. There is an issue for that DATACOUCH-367, the release notes seem to contradict with the pom file.
That's a glitch in the release notes. For service releases of a release train only upgrades to bugfix versions are allowed. Upgrading to 2.5.6 requires a new GA release (i.e. Spring Data Cassandra 3.1)