You need to set both in case of lwt. your regular non -serial consistency level will only applied during commit phase of lwt.
On Wed, 6 Mar, 2024, 03:30 Weng, Justin via user, <user@cassandra.apache.org> wrote: > Hi Cassandra Community, > > > > I’ve been investigating Cassandra Paxos v2 (as implemented in CEP-14 > <https://cwiki.apache.org/confluence/display/CASSANDRA/CEP-14%3A+Paxos+Improvements>) > which improves the performance of lightweight transaction (LWT). But I’ve > got a question about setting the commit consistency level for LWT after > upgrading Paxos. > > > > In cqlsh > <https://docs.datastax.com/en/cql-oss/3.3/cql/cql_reference/cqlshSerialConsistency.html>, > gocql <https://github.com/gocql/gocql/blob/master/session.go#L1247> and Python > driver > <https://docs.datastax.com/en/developer/python-driver/3.29/api/cassandra/query/#cassandra.query.Statement.serial_consistency_level>, > there are two settings for consistency levels: normal Consistency Level and > Serial Consistency Level. As mentioned in the cqlsh documentation > <https://docs.datastax.com/en/cql-oss/3.3/cql/cql_reference/cqlshSerialConsistency.html>, > Serial Consistency Level is only used for LWT and can only be set to either > SERIAL or LOCAL_SERIAL. However, the Steps for Upgrading Paxos > <https://github.com/apache/cassandra/blob/trunk/NEWS.txt#L532> and CEP-14 > <https://cwiki.apache.org/confluence/display/CASSANDRA/CEP-14%3A+Paxos+Improvements> > mention that ANY or LOCAL_QUOROM can be used as the commit consistency > level for LWT after upgrading Paxos to v2. Therefore, I have a question > about how to correctly set the commit consistency level to ANY or > LOCAL_QUORUM for LWT. Namely, which consistency level should I set, the > normal Consistency Level or Serial Consistency Level? > > > > Any help would be really appreciated. > > > > Thanks, > > Justin >
