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From Chris Wirt <>
Subject Re: Rollback question regarding system metadata change
Date Tue, 01 Oct 2013 22:45:02 GMT
Yep they still work. They dont acutally have any of the new system CF
created for 2.0, paxos, etc.. but they do have new rows in the
schema_columns table preventing startup and bootstrapping of new

If I drop the keyspace and recreate quickly, I'm guessing that will
cause quite a large mess for a couple minutes while i recreate the
schema and load the sstables.
But anyway, actions to do this would be:
- drop schema (wont actually delete data?)
- create schema (will create all the metadata and leave my data
directories alone?)
- on each node run nodetool refresh (will load my existing data?)
sound realistic?

On 1 October 2013 19:40, Robert Coli <> wrote:
> On Tue, Oct 1, 2013 at 10:51 AM, Christopher Wirt <>
> wrote:
>> Moving back to 1.2.10. What is the procedure roll back from 2.0.1?
>> Changes in the system schema seem to make this quite difficult.
> ...
> First, unfortunately downgrade is not, in my understanding, a supported
> operation.
>> In my efforts I’ve now completely taken DC3 offline and already tried:
> Are you seeing the new schema on the 1.2.10 nodes?
> If the schema has been modified globally via gossip, I don't understand how
> your 1.2.10 nodes are currently working. It seems like there may be a risk
> of them not working if you restart them?
> If the schema changes have been seen globally, the safest solution is to
> dump, drop, and re-create your schema. This is likely to require a downtime
> across all DCs. You could probably do this semi-online by doing the
> (theoretical) clone-a-keyspace-with-hard-links operation, but that would
> require application changes/synchronization etc...
> =Rob

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