It's not common for me to recommend CouchDB, but this is one instance it's great for: synching complete datasets for disconnected use. Cassandra treats disconnection as a problem, not something that should occur in the normal plan of operations.
-----Original Message----- From: Colin Yates <colin.ya...@gmail.com> Date: Mon, 12 Apr 2010 10:52:32 To: <user@cassandra.apache.org> Subject: Off line client nodes? Hi, In our architecture, our consultants want to perform some analysis on the train, disconnected from the web. How can I achieve this in Cassandra? I realise this isn't quite the use-case that was thought about when the clustering was designed, but will it work? Scenario: - consultantA is in his office running a cassandra node on his laptop. - this node *very* periodically (almost on a manual basis) connects to the cluster and synchronises - consultant then gets some coffee - consultant then disconnects and sits on a train, happily using their app against the local node - consultant goes and plays golf whilst billing client for 'management activities) (we know you do!) - consultant plugs in at the end of the day and all changes are synced back to the cluster A few caveats: - the sync might not be atomic - the consultant *will* get bored and disconnect before the sync has finished - the consultant should only see a tiny, well-defined fragment of the cluster data - i.e. a key range-set for example Is this do-able or should I write a custom 'slurper' which builds the local standalone client node? I really don't want to do this.... Many thanks, Col
