Cassandra - Importent Key Components

Importent Key Components/Terminologies for configuring Cassandra

Following are must know terminology before you start diving deep into Cassandra. I will explain each of them seprately in more details in my folowing posts as and when it will be required. For the time being it is enough to know them and what they are used for

Gossip

A peer-to-peer communication protocol to discover and share location and state information about the other nodes in a Cassandra cluster.

Partitioner

A partitioner determines which node will receive the first replica of a piece of data, and how to distribute other replicas across other nodes in the cluster

Replication factor

Replication factor defines the redundancy of the data. A replication factor of 1 means that there is only one copy of each row. A replication factor of 2 means two copies of each row, where each copy is stored on a different node. The replication factor is defined for each datacenter, in case you have more than one datacener in Cassandra cluster

Replica placement strategy

Cassandra stores replicas of data on multiple nodes to ensure reliability and fault tolerance. A replication strategy defines which nodes will hold the replicas.
When creating a keyspace, you must define the replica placement strategy and the number of replicas you want. We will discuss later in detail how to create keyspace.

Snitch

A snitch defines groups of machines into datacenters and racks (the topology) that the replication strategy uses to place replicas. Snitch is configured at cluster level and therefore you must configure snitch when you create a cluster. All snitches use a dynamic snitch layer, which monitors performance and chooses the best replica for reading.
Since default SimpleSnitch does not recognize datacenter or rack information you must use GossipingPropertyFileSnitch for production.

The cassandra.yaml configuration file

The main configuration file for setting the initialization properties for a cluster ( This file is you can say an equivalent of SPfile/Pfile in oracle).
Caching parameters for tables, properties for tuning and resource utilization, timeout settings, client connections, backups, security etc you can define in cassandra.yaml file.

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