Consistency

Consistency has been introduced to Dynomite in version 0.5.0 in the local region. There are two configurations.

DC_ONE: Reads and writes are propagated synchronously only to the node in the local Rack (Availability Zone) and asynchronously replicated to other Racks and regions.

DC_QUORUM: Reads and writes are propagated synchronously to quorum number of nodes in the local region and asynchronously to the rest. A quorum of responses are returned to the client.

Consistency can be configured for read or write operations separately (clusterwide). Adding consistency can be done through the stats port (default 22222):

curl http://localhost:22222/set_consistency/read/dc_quorum

curl http://localhost:22222/set_consistency/write/dc_quorum

To check the node level consistency:

curl "http://localhost:22222/get_consistency"

For example the output can be

Read Consistency: DC_ONE
Write Consistency: DC_ONE