Anthony, I'm just getting my feet wet with Cassandra, so I'm far from an expert, but I'm curious whether you saw my posting a few days ago about using the EC2 "public" IP addreses with cassandra: http://www.mail-archive.com/user@cassandra.apache.org/msg05692.html
*If* I understand the problem correctly, it seems like you could create some new EC2 nodes using this patched version of the code, then migrate your existing nodes to new EC2 nodes, but giving each new node a public IP. Once your entire EC2 cluster was up and running on the public addresses, you should be able to use those public addresses to migrate to some other site outside of EC2. Am I missing something obvious? (Quite possible, since I haven't actually tested this) On Thu, Sep 02, 2010 at 01:09:46PM -0500, Anthony Molinaro wrote: > Hi, > > We're running cassandra 0.6.4, and need to do a data center move of > a cluster (from EC2 to our own data center). Because of the way the > networks are set up we can't actually connect these boxes directly, so > the original plan of add some nodes in the new colo, let them bootstrap > then decommission nodes in the old colo until the data is all transfered > will not work. > > So I'm wondering if the following will work > > 1. take a snapshot on the source cluster > 2. rsync all the files from the old machines to the new machines (we'd most > likely be reducing the total number of machines, so would do things like > take 4-5 machines worth of data and put it onto 1 machine) > 3. bring up the new machines in the new colo > 4. run cleanup on all new nodes? > 5. run repair on all new nodes? > > So will this work? If so, are steps 4 and 5 correct? > > I realize we will miss any new data that happens between the snapshot > and turning on writes on the new cluster, but I think we might be able > to just tune compaction such that it doesn't happen, then just sync > the files that change while the data transfers happen? > > Thanks, > > -Anthony > > -- > ------------------------------------------------------------------------ > Anthony Molinaro <antho...@alumni.caltech.edu> -- Peter Fales Alcatel-Lucent Member of Technical Staff 1960 Lucent Lane Room: 9H-505 Naperville, IL 60566-7033 Email: peter.fa...@alcatel-lucent.com Phone: 630 979 8031
