The main characteristic of Cassandra is that it is not a database, but a distributed network service composed of a bunch of database nodes, a write operation to Cassandra will be copied to the other nodes, and the read operation to Cassandra will be routed to a node to read. For a Cassandra cluster, scaling performance is a simple matter, just add nodes to the cluster. Here are a number of reasons to choose Cassandra for your website. Compared with other databases, there are three outstanding features:Flexible ModeWith Cassandra, like the document store, you don't have to resolve the fields in the record in advance. You can add or remove fields whenever the system is running. This is an astonishing efficiency boost, especially in large deployments. ScalabilityCassandra is a purely horizontal extension. To add more capacity to a cluster, you can point to another computer. You don't have to restart any processes, change application queries, or manually migrate any data.Multi-Data centerYou can adjust your node layout to avoid a fire in a data center, and an alternate datacenter will have at least a full copy of each record. Some other features that make Cassandra more competitive:Scope QueryIf you don't like all of the key-value queries, you can set the range of the keys to query.list Data StructuresIn mixed mode, you can add a super column to a 5-D. For each user's index, this is very convenient.Distributed Write OperationsYou can read or write any data at any time in any place. And there will be no single point of failure.
Cassandra is a set of open source distributed NoSQL database system
