Hi,
We were deploying a second DC today with 3 seed nodes (30 nodes in total)
and we have noticed that all seed nodes reported the following:
INFO 10:20:50 Create new Keyspace: KeyspaceMetadata{name=system_traces,
params=KeyspaceParams{durable_writes=true,
replication=ReplicationParams{class=org.apache.cassandra.locator.SimpleStrategy,
replication_factor=2}}, ...
followed by similar lines for system_distributed and system_auth. Is this
to be expected?
Cassandra version is 3.0.15. The DC2 was added to NTS replication setting
for all of the non-local keyspaces in advance, even before starting any of
the new nodes. The schema versions reported by `nodetool describecluster'
are consistent accross DCs, that is: all nodes are on the same version.
All new nodes use auto_bootstrap=true (in order for
allocate_tokens_for_keyspace=mydata_ks to take effect), the seeds ignore
this setting and report it. The non-seed nodes didn't try to create the
system keyspaces on their own.
I would expect that even if we don't add the DC2 in advance, the new nodes
should be able to learn about existing system keyspaces and wouldn't try to
create their own. Ultimately we will run `nodetool rebuild' on every node
in DC2, but I would like to understand why this schema disagreement
initially?
Thanks,
--
Oleksandr "Alex" Shulgin | Database Engineer | Zalando SE | Tel: +49 176
127-59-707
