CODEWITHSUNDEEP
google-cloud-platformgoogle-cloud-pubsub
Shaju Nr
Shaju Nr

Reputation: 358

Message stays in GCP Pub/Sub even after acknowledge using GCP REST API

I am using the following GCP Pub/Sub REST APIs for pulling and Acknowledging messages. For pulling message:-

POST https://pubsub.googleapis.com/v1/projects/myproject/subscriptions/mysubscription:pull
{
  "returnImmediately": "false",
  "maxMessages": "10"
}

To acknowledge message:-

POST https://pubsub.googleapis.com/v1/projects/myproject/subscriptions/mysubscription:acknowledge
{
  "ackIds": [
    "dQNNHlAbEGEIBERNK0EPKVgUWQYyODM2LwgRHFEZDDsLRk1SK..."
  ]
}

I am using the postman tool for calling the above APIs.But I can see the same message with same messageId and a different ackId even after the acknowledgement, when I pull the messages next time.Is there any mechanism available to exclude the acknowledged messages in gcp pull (subscriptions/mysubscription:pull)

Upvotes: 1

Views: 1379

Answers (1)

Kamal Aboul-Hosn
Kamal Aboul-Hosn

Reputation: 17206

Cloud Pub/Sub is an at-least-once delivery system, so some duplicates are expected. However, if you are always seeing duplicates, it is likely that you are not acknowledging the message before the ack deadline passes. The default ack deadline is 10 seconds. If you do not call ack within that time period, then the message will be redelivered. You can set the ack deadline on a subscription to up to 600 seconds.

If all of your messages are expected to take a longer time to process, then it is best to increase the ack deadline. If only a couple of messages will be slow and most will be processed quickly, then it's better to use the modifyAckDeadline call to increase the ack deadline on a per-message basis.

Upvotes: 2

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