On Tue, Jul 5, 2011 at 8:58 AM, aaron morton <aa...@thelastpickle.com>wrote:
> How do you change the name of a cluster? The FAQ instructions do not seem > to work for me - are they still valid for 0.7.5? > Is the backup / restore mechanism going to work, or is there a > better/simpler to copy data from multi-node to single-node? > > > Bug fixed on 0.7.6 > https://github.com/apache/cassandra/blob/cassandra-0.7.6-2/CHANGES.txt#L21 > > > <https://github.com/apache/cassandra/blob/cassandra-0.7.6-2/CHANGES.txt#L21>Also > you should move to 0.7.6 to get the Gossip fix > https://github.com/apache/cassandra/blob/cassandra-0.7.6-2/CHANGES.txt#L6 > > <https://github.com/apache/cassandra/blob/cassandra-0.7.6-2/CHANGES.txt#L6>When > it comes to moving the data back to a single node I would: > - run repair > - snapshot prod node > - clear all data including the system KS data from the dev node > - copy the snapshot data for only your KS to the dev node into the correct > directory, e.g. data/<my-keyspace> . > - start the dev node > - add your KS, the node will now load the data > > Ignoring the system data means the dev node can sort it's cluster name and > token out using the yaml file. > > Even with 3 nodes and RF 3 it's impossible to ever say that one node has a > complete copy of the data. Running repair will make it more likely, but the > node could drop a mutation message during the repair or drop off gossip for > few seconds. If you really want to have *everything* from the prod cluster > then copy the data from all 3 nodes onto the dev node and compact it down. > Is it possible the snapshots from different nodes have the same name? > > Hope that helps. > > ----------------- > Aaron Morton > Freelance Cassandra Developer > @aaronmorton > http://www.thelastpickle.com > > On 5 Jul 2011, at 03:05, Ross Black wrote: > > Hi, > > I am using Cassandra 0.7.5 on Linux machines. > > I am trying to backup data from a multi-node cluster (3 nodes) and restore > it into a single node cluster that has a different name (for development > testing). > > The multi-node cluster is backed up using clustertool global_snapshot, and > then I copy the snapshot from a single node and replace the data directory > in the single node. > The multi-node cluster has a replication factor of 3, so I assume that > restoring any node from the multi-node cluster will be the same. > When started up this fails with a node name mismatch. > > I have tried removing all the Location* files in the data directory (as per > http://wiki.apache.org/cassandra/FAQ#clustername_mismatch) but the single > node then fails with an error message: > org.apache.cassandra.config.ConfigurationException: Found system table > files, but they couldn't be loaded. Did you change the partitioner? > > > How do you change the name of a cluster? The FAQ instructions do not seem > to work for me - are they still valid for 0.7.5? > Is the backup / restore mechanism going to work, or is there a > better/simpler to copy data from multi-node to single-node? > > Thanks, > Ross > > >
