How many subscriptions are a lot?
Think I had about 20 at the most (high priority projections had their own). Now I’m done to 3, and it seems like I’m rid of the timeouts (but with higher latency due to bigger transactions).
Note that the write side runs in the same process, so high load means a lot of activity, not just projections.
Also what is your heartbeat set to?
Tried from 10 sec to 5 minutes, didn’t make much difference under heavy load, the timeouts came either way
Remember things like go pauses can also go into this