Publish rate is not equal to Pull rate

[amashruwala]

I have 75 instances of streaming pull subscriber with the following settings:

Subscription:

- Message retention duration = 10minutes

- Expiration Policy = 1 day

- Enable Exactly Once Delivery = false

Subscriber:

- FlowControlSettings - Max Outstanding Element Count = 80, Max Byte Count = 100000000

- ClientCount = 80

I am seeing a lot of unacked messages and a lot of latency as a result and I was wondering:

1) Is my subscriber too slow?

2) Is the pull rate far too less?

For 1) I am seeing in the dashboards that the ack rate (subscription/ack_message_count) per unit time is equal to the pull rate (subscription/sent_message_count) per unit time. I have ruled out 1) as the cause of my latency

For 2) can you suggest if I need to increase the Pull rate to match the publish rate? How do I increase the pull rate to match the publish rate? Thank you!