Glossary

We will list here the terms that are related to the Socket.IO ecosystem.

Adapter

An Adapter is a server-side component which is responsible for:

• storing the relationships between the Socket instances and the rooms
• broadcasting events to all (or a subset of) clients

There are currently two official adapters:

• the in-memory adapter, which is included by default with the Socket.IO server
• the Redis adapter, which is useful when scaling horizontally (see here)

The in-memory adapter can be extended to add support for other messaging systems, like RabbitMQ or Google Pub/Sub for example.