pub sub flow control

[kadu]

• Can anyone give details on the Dynamic rate limiting implemented by the Pub/Sub system? I couldn't find any details on the gcloud docs  or  the faq pages.
  
  Here is my pubsub usage:

Im planning to use pubsub in our production. Right now, I have 1 topic, 1 subscription and  1 subscriber (Webhook HTTPS callback). Sometimes my subscriber can throw an exception (very rarely), in that situation my subscriber shall return a 400 response back to the pubsub, so that the pubsub can retain the message and retry.  

If the pubsub gets a 400 response from the subscriber, will it severely impact the flow rate of other messages? Given the scarce documentation on how the flow control is implemented, i'm mainly concerned about the impact of one bad message on latencies of all other good messages.

I can split  my one topic into multiple topics and multiple subscriptions, if  it helps reduce the impact of a bad message.

[Nick]

Hey Kadu,

As described in the documentation, an error response from a subscriber will trigger a retry according to exponential backoff. It is best if each channel serves a single function, so that what are really different channels aren't impacted by each other's error rates.

Let me know if you had any other questions! I'll be glad to help.

Sincerely,

Nick
Cloud Platform Community Support