Disable the acknowledgement need for subscribers

[Alejandro Holguin Mora]

Hi, I will like to know if there is a way to disable the need from Google Pub/Sub to receive the acknowledgement message from a Subscriber when you push a specific message? 

If the message is somehow lost or not received by the subscriber configure Google PubSub to not send or try to send the same message avoiding duplicates. Is this possible?

[Jun Lu]

Hi, 

It does not seem that you can disable the acknowledge feature at Cloud Pub/Sub, and it is expected that occasional duplicates are to be expected if the messages have not been ack'ed since Pub/Sub guarantees at-least-once message delivery [1].  

[1] https://cloud.google.com/pubsub/docs/faq#technical

[Alejandro Holguin Mora]

Ju hi

Is it possible to configure:

1) The period of time when the Google Pub/Sub Subscriber try to re send a message that has not receive the acknowledge messages? As an example after 96 hours from the first attempt?

 2) In the same subscriber create a seek function that allow me to search and find messages that have not receive the acknowledgement messages after 48 hours and discharge or delete those messages?

[Jun Lu]

Hi, 

1) Do you mean the Publisher try to re-send the message that has not been ack'ed by the subscriber? 

2) Yes, and the unacknowledged message is retained in a subscription for up to message_retention_duration after it is published (the default is 7 days but you can config this to 48 hours, after which the message will not be retained in the subscription).