DeadLetterPolicy(mapping=None, *, ignore_unknown_fields=False, **kwargs)Dead lettering is done on a best effort basis. The same message might be dead lettered multiple times.
If validation on any of the fields fails at subscription creation/updation, the create/update subscription request will fail.
| Attributes | |
|---|---|
| Name | Description | 
| dead_letter_topic
   :noindex: | strOptional. The name of the topic to which dead letter messages should be published. Format is projects/{project}/topics/{topic}.The Pub/Sub service
   account associated with the enclosing subscription's parent
   project (i.e.,
   service-{project_number}@gcp-sa-pubsub.iam.gserviceaccount.com)
   must have permission to Publish() to this topic.
   
   The operation will fail if the topic does not exist. Users
   should ensure that there is a subscription attached to this
   topic since messages published to a topic with no
   subscriptions are lost. | 
| max_delivery_attempts
   :noindex: | intOptional. The maximum number of delivery attempts for any message. The value must be between 5 and 100. The number of delivery attempts is defined as 1 + (the sum of number of NACKs and number of times the acknowledgment deadline has been exceeded for the message). A NACK is any call to ModifyAckDeadline with a 0 deadline. Note that client libraries may automatically extend ack_deadlines. This field will be honored on a best effort basis. If this parameter is 0, a default value of 5 is used. |