How to deal with slow clients

Problem

You have multiple clients on your cluster. Some clients may be running slow, causing back pressure in the cluster. You want to know what strategies exist.

Discussion

The exact strategy used will likely vary from cluster client to cluster client, but four common strategies exist:

• Drop the message. The client will not have received the message, and the cluster won't care about the fact the message is lost.
• Disconnect slow clients. The slow client is disconnected from the cluster so that it no longer causes cluster slowness and backpressure.
• Exit the cluster. The fact that the client is running slow is a critical failure for the cluster. The cluster exits to prevent any further processing.
• Retry endlessly. The cluster never gives up trying to send the message until either the cluster client recovers, or is timed out.

See Also

• Aeron Cookbook
• Publications & Subscriptions - Back Pressure