This patch set adds a few new features in order to fix issue
The list of changes is briefly as follows:
- Add a new `LWT` flag to `cql3::prepared_metadata`,
which allows clients to clearly distinguish betwen lwt and
non-lwt statements without need to execute some custom parsing
logic (e.g. parsing the prepared query with regular expressions),
which is obviously quite fragile.
- Introduce the negotiation procedure for cql protocol extensions.
This is done via `cql_protocol_extension` enum and is expected
to have an appropriate mirroring implementation on the client
driver side in order to work properly.
- Implmenent a `LWT_ADD_METADATA_MARK` cql feature on top of the
aforementioned algorithm to make the feature negotiable and use
it conditionally (iff both server and client agrees with each
other on the set of cql extensions).
The feature is meant to be further utilized by client drivers
to use primary replicas consistently when dealing with conditional
statements.
* git@github.com:ManManson/scylla feature/lwt_prepared_meta_flag_2:
lwt: introduce "LWT" flag in prepared statement metadata
transport: introduce `cql_protocol_extension` enum and cql protocol extensions negotiation
8bd7359d93