Setting consistency levels
Set the consistency level to control the accuracy of the data returned by read request.
In a distributed system such as DataStax Enterprise, the most recent value of data is not
necessarily on every node all the time. The client application configures the consistency level
per request to manage response time versus data accuracy. By tracing activity on a five-node
cluster, this tutorial shows the difference between these consistency levels and the number of
replicas that participate to satisfy a request:
- ONE
Returns data from the nearest replica.
- QUORUM
Returns the most recent data from the majority of replicas.
- ALL
Returns the most recent data from all replicas.
Follow instructions to set up five nodes on your local computer, trace reads at different consistency levels, and then compare the results.