Cassandra – gossip protocol

Gossip is a protocol wherein periodically the nodes exchange information with other nodes about the nodes they know; this way, all the nodes obtain information about each other via this peer-to-peer communication mechanism. It's very similar to real-world and social media world gossip.

Cassandra executes this mechanism every second, and one node is capable of exchanging gossip information with up to three nodes in the cluster. All these gossip messages have a version associated with them to track the chronology, and the older gossip interaction updates are overwritten chronologically by newer ones.

Now that we know what Cassandra's gossip is like at a very high level, let's have a closer look at it and understand the purpose of this chatty protocol. Here are the two broad purposes served by having this in place:

• Bootstrapping

• Failure scenario handling—detection and recovery

Let's understand what they mean in action and what their contribution is towards the well-being...