On Sun, Sep 22, 2013 at 7:02 PM, Shashilpi Krishan < shashilpi.kris...@wizecommerce.com> wrote:
> We had a Cassandra cluster (running with v1.0.7) spread across 3 data > centers with each data center having 16 nodes. We started upgrading that to > 2.0 but realized that we can’t go directly to 2.0 due to read failures, > hence to avoid down time we have to go from 1.0 à 1.1 à 1.2 à 2.0. > In general you should not run a Cassandra version X.Y.Z in production where Z < 5. Although I notice down thread that this cluster is not serving a critical business function... :) As you have discovered, you also should not generally try to upgrade across more than one major version. > Now problem is while upgrading from 1.2 à 2.0 we saw below errors > flooding the system.log files in one data center only until we upgraded all > the nodes in every DC to 2.0. We think that moment last node was upgraded > then this error was gone. Does anyone has idea what could have been causing > this? Is it because of some version incompatibility? > I would probably file a JIRA with relevant details/log snippets. It is quite possible that this is expected, major version upgrades semi-frequently spam logs with non-pathological error messages. =Rob
