Hi community, Google Cloud PubSub has a feature called snapshot[1], which allows us to apply snapshots to subscriptions.
I recently have a requirement to update the "filter" of subscription, but "filter" is unable to modify once it is created. Therefore, I create a snapshot on the current subscription and apply it to a new subscription. After resuming the Flink application with the new subscription, I got following error repeatedly: ``` org.apache.flink.util.SerializedThrowable: INVALID_ARGUMENT: You have passed a subscription that does not belong to the given ack ID (resource=projects/xxxxx/subscriptions/xxxx). at io.grpc.stub.ClientCalls.toStatusRuntimeException(ClientCalls.java:244) ~[?:?] at io.grpc.stub.ClientCalls.getUnchecked(ClientCalls.java:225) ~[?:?] at io.grpc.stub.ClientCalls.blockingUnaryCall(ClientCalls.java:142) ~[?:?] at com.google.pubsub.v1.SubscriberGrpc$SubscriberBlockingStub.acknowledge(SubscriberGrpc.java:1628) ~[?:?] at org.apache.flink.streaming.connectors.gcp.pubsub.BlockingGrpcPubSubSubscriber.acknowledge(BlockingGrpcPubSubSubscriber.java:99) ~[?:?] at org.apache.flink.streaming.connectors.gcp.pubsub.common.AcknowledgeOnCheckpoint.notifyCheckpointComplete(AcknowledgeOnCheckpoint.java:84) ~[?:?] at org.apache.flink.streaming.connectors.gcp.pubsub.PubSubSource.notifyCheckpointComplete(PubSubSource.java:208) ~[?:?] at org.apache.flink.streaming.api.operators.AbstractUdfStreamOperator.notifyCheckpointComplete(AbstractUdfStreamOperator.java:130) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.StreamOperatorWrapper.notifyCheckpointComplete(StreamOperatorWrapper.java:99) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.SubtaskCheckpointCoordinatorImpl.notifyCheckpointComplete(SubtaskCheckpointCoordinatorImpl.java:319) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.StreamTask.notifyCheckpointComplete(StreamTask.java:1083) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.StreamTask.lambda$notifyCheckpointCompleteAsync$11(StreamTask.java:1048) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.StreamTask.lambda$notifyCheckpointOperation$13(StreamTask.java:1071) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.StreamTaskActionExecutor$SynchronizedStreamTaskActionExecutor.runThrowing(StreamTaskActionExecutor.java:93) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.mailbox.Mail.run(Mail.java:90) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.processMail(MailboxProcessor.java:317) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.mailbox.MailboxProcessor.runMailboxLoop(MailboxProcessor.java:189) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.StreamTask.runMailboxLoop(StreamTask.java:617) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:581) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.runtime.taskmanager.Task.doRun(Task.java:755) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at org.apache.flink.runtime.taskmanager.Task.run(Task.java:570) ~[flink-dist_2.12-1.12.2.jar:1.12.2] at java.lang.Thread.run(Thread.java:834) ~[?:?] ``` I think the "ack ID" stored in savepoint became invalid after I changed the subscription. Since PubSub has an at-least-once guarantee, it seems safe to just ignore these errors, or even not saving "ack ID" in checkpoint/savepoint? I am new here. Is there any suggestion for follow-up? Can I just create a Jira ticket for this feature request? [1] https://cloud.google.com/pubsub/docs/replay-overview Thanks, sayuan