cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Oleksandr Shulgin <>
Subject New token allocation and adding a new DC
Date Tue, 16 Jan 2018 14:51:07 GMT

We want to add a new rack to an existing cluster (a new Availability Zone
on AWS).

Currently we have 12 nodes in 2 racks with ~4 TB data per node.  We also
want to have bigger number of smaller nodes.  In order to minimize the
streaming we want to add a new DC which will span 3 racks and then
decommission the old DC.

Following the documented procedure we are going to create all nodes in the
new DC with auto_bootstrap=false and a distinct dc_suffix.  Then we are
going to run `nodetool rebuild OLD_DC` on every node.

Since we are observing some uneven load distribution in the old DC, we
wanted to make use of new token allocation algorithm of Cassandra 3.0+ when
building the new DC.

To our understanding, this is currently not supported, because the new
algorithm can only be used during proper node bootstrap?

In theory it should still be possible to allocate tokens in the new DC by
telling Cassandra which keyspace to optimize for and from which remote DC
the data will be streamed ultimately, or am I missing something?

Reading through the original implementation ticket I didn't find any
reference to interaction with rebuild:
Nor do I find any open tickets that would discuss the topic.

Is it reasonable to open an issue for that or is there some obvious blocker?


View raw message