CODEWITHSUNDEEP
cassandracqlcql3
Jay
Jay

Reputation: 20146

Is it possible to have a Cassandra table that doesn't replicate?

There is one particular table in the system that I actually want to stay unique on a per server basis.

i.e. http://server1.example.com/some_stuff.html and http://server2.example.com/some_stuff.html should store and show data unique to that particular server. If one of the server dies, that table and its data goes with it.

Upvotes: 4

Views: 4245

Answers (2)

keelar
keelar

Reputation: 6026

I think CQL does not support table-level replication factors (see available create table options). One alternative is to create a key-space with a replication factor = 1:

    CREATE KEYSPACE <ksname>
        WITH replication = {'class':'<strategy>' [,'<option>':<val>]};

    Example:
     To create a keyspace with SimpleStrategy and "replication_factor" option
     with a value of "1" you would use this statement:
        CREATE KEYSPACE <ksname>
            WITH replication = {'class':'SimpleStrategy', 'replication_factor':1};

then all tables created in that key-space will have no replication.

If you would like to have a table for each node, then I think Cassandra does not directly support that. One work-around is to start an additional Cassandra cluster for each node where each cluster only have one node.

Upvotes: 3

John
John

Reputation: 1462

I am not sure why you would want to do that, but here is my take on this:

Distribution of the actual your data among the nodes in your Cassandra cluster is determined by the row key.

Just setting the replication factor to 1 will not put all data from one column family/table on 1 node. The data will still be split/distributed according to your row key.

Exactly WHERE your data will be stored is determined by the row key along with the partitioner as documented here. This is an inherent part of a DDBS and there is no easy way to force this.

The only way I can think of to have all the data for one server phisically in one table on one node, is:

  1. use one row key per server and create (very) wide rows, (maybe using composite column keys)
  2. and trick your token selection so that all row key tokens map to the node you are expecting (http://wiki.apache.org/cassandra/Operations#Token_selection)

Upvotes: 1

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