# High Availability

This simulation shows how ScyllaDB replicates data across nodes and zones (racks),
and how the replication factor (RF) and the consistency level (CL) control
which requests succeed.

* Send writes and reads from each client. Each request goes through a
  coordinator to the replicas of the key.
* Click a node to stop or start it. Click the border of a zone to stop or
  start all of its nodes.
* Change the number of nodes, zones, clients, the RF, and the CL.
* Turn on **Smart Drivers** to compare token-aware routing with routing
  through a proxy node.

#### NOTE
This is an educational simulation. It is simplified, and it does not show
all of the ScyllaDB internals exactly.

Source code: [tzach/scylladb-ha-demo on GitHub](https://github.com/tzach/scylladb-ha-demo)