how to take a keyspace as a dump in cassandra?

Question

I need to take a keyspace from the server as a dump and restore that dump to my local cassandra, I know to do in mysql but how to do in nosql ? I learn from site that nodetool ,snapshot and csv file format can achieve this,but I unable to got it ?

Answer 1

You can do this with "nodetool". For a good reference documentation take a look here: http://www.datastax.com/docs/1.1/backup_restore

Roughly you need to perform the following steps:

1. take a "snapshot" of the keyspace using: nodetool snapshot <keyspace-name>. This is run on the server, where you want to take generates a "snapshot". It will do that, storing a "snapshot" for each table of the keyspace.
2. copy the "snapshots" to your local server. Do this for each keyspace table: <cassandra-dir>/data/<keyspace-name>/<table-name>/snapshots/ (look for the "latest" taken snapshot - when you take the snapshot it tells you the "name"/"ID" of the snapshot taken).
3. in your local server, before you place the "server" snapshots do the following: stop cassandra, delete the content of that "keyspace"(again for each keyspace table: <cassandra-dir>/data/<keyspace>/<table-name>/) and then place the "server" snapshots in each respective "keysapce table" (directly in the <cassandra-dir>/data/<keyspace>/<table-name>/ and not in the "snapshot" directory).
4. restart the local server, and you should have the data from the server in your local server.

HTH.