IPC communication | Non critical subscription & Backpressure

[vitor-tadashi]

Hi Aeron team, I hope you’re doing well.

I’d like to ask whether it is possible to prevent backpressure from impacting a specific subscription when using IPC communication.

My use case is the following: I have two subscriptions on the same IPC stream. One subscription is critical and must be protected from latency or performance impact. The other subscription is non-critical and runs on non-isolated / free cores. I do not want the non-critical subscription to impact the critical one in any way.

At the moment, I am forced to run everything in the best possible configuration to minimize impact on the critical path, so I may be missing something here. I would like to know whether Aeron supports any way to disable backpressure for one subscription, or otherwise isolate backpressure behavior per subscription.

Any guidance or recommendation would be greatly appreciated. Thank you.

[mikeb01]

You can look at using tether=false on the subscription that has lower priority. You may need to decrease the tethering timeouts so it can quickly allow the slow subscription to drop off if is is running slower. Be aware that this means that the slower subscription will lose data. The other option would be to record this data to archive and have the slow subscription replay the recording.