Event Processor Client - Invalid Offset Error

Question

I'm encountering an issue with the EventProcessorClient in Azure Event Hubs. Specifically, I'm receiving the following error when trying to process events:

The supplied offset '38655200720' is invalid. The last offset in the system is '8590386784'. TrackingId: 290144a9-74ab-4eb2-9fb0-bf13e29ac44f_B18, SystemTracker: dev-platform-app-tenant:eventhub:tenant.udm.license.v1~32766, Timestamp: 2024-11-27T11:11:06

Despite clearing metadata and offset information from the Blob Storage container used for checkpointing and ensuring the correct configurations are set for the EventProcessorClient, I continue to encounter this invalid offset error.

I have even tried deleting the consumer group information from Blob Storage, the whole folder still somehow getting the same issue.

Tried manually resetting offsets , but the error persists.

Can you help determine the cause of the invalid offset error and provide recommendations on how to resolve it and ways to prevent it in production.

How is the system still referencing the invalid offset even after completely clearing the consumer group and offset data from Blob Storage? Could there be any other underlying system or cache that is storing this offset information?

Answer 1

@Neeraj Mahajan

I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this! Since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others ", I'll repost your solution in case you'd like to accept the answer .

**Ask:**I'm encountering an issue with the EventProcessorClient in Azure Event Hubs. Specifically, I'm receiving the following error when trying to process events:

The supplied offset '38655200720' is invalid. The last offset in the system is '8590386784'. TrackingId: 290144a9-74ab-4eb2-9fb0-bf13e29ac44f_B18, SystemTracker: dev-platform-app-tenant:eventhub:tenant.udm.license.v1~32766, Timestamp: 2024-11-27T11:11:06

Despite clearing metadata and offset information from the Blob Storage container used for checkpointing and ensuring the correct configurations are set for the EventProcessorClient, I continue to encounter this invalid offset error.

I have even tried deleting the consumer group information from Blob Storage, the whole folder still somehow getting the same issue.

Tried manually resetting offsets , but the error persists.

Can you help determine the cause of the invalid offset error and provide recommendations on how to resolve it and ways to prevent it in production.

How is the system still referencing the invalid offset even after completely clearing the consumer group and offset data from Blob Storage? Could there be any other underlying system or cache that is storing this offset information?

Solution: Thank you for your reply. I ended up deleting the entire consumer group folder from the blob storage, and redeploying the EventProcessorClient resolved the issue for me. My consumer group folder was created again in the blob after successfully running. I had originally hosted EventProcessorClient as a background service in a container app, so it’s possible that some configurations were causing the issue. I appreciate your recommendations—thanks again!

If I missed anything please let me know and I'd be happy to add it to my answer, or feel free to comment below with any additional information.

If you have any other questions, please let me know. Thank you again for your time and patience throughout this issue.