Redis Streams, a data type introduced with Redis 5.0 is an append-only log data structure. One of its features includes "consumer groups" that allows a group of clients to co-operate consuming a different portion of the same stream of messages.

This scaler can check the Pending Entries List (see XPENDING https://redis.io/commands/xpending) for a specific Consumer Group of a Redis Stream and scale-out the Deployment as per the count returned (by XPENDING command). If you have a Redis Streams consumer application that is unable to keep up with the rate of production, KEDA can help by auto-scaling the no. of instances (part of the same consumer group) so that it can start sharing the processing workload.

• Scaler Source: Redis Streams (Pending Entries List aka PEL)
• Authentication: Password-based authentication supported by Redis