Redis Pub/Sub output buffer limits and client disconnection

Client Buffer Management in Pub/Sub

Redis Pub/Sub follows a fire-and-forget model where messages are pushed to connected subscribers in real-time. Because these messages are not persisted, Redis manages the delivery via output buffers for each client.

When a subscriber cannot consume messages as fast as the publisher produces them, the output buffer grows. There are specific configuration limits designed to prevent a single slow consumer from exhausting the total server memory, but these limits trigger a hard disconnection of the client.

In a high-throughput environment, it is unclear how to balance the risk of memory exhaustion against the stability of long-lived subscriber connections.

• What are the specific default thresholds for client-output-buffer-limit pubsub?
• Does exceeding these limits result in a silent disconnection or a specific error returned to the client?