Why are we getting azure platform error - "Exception encountered when listening to event stream. The HTTP/2 connection faulted" for Time triggered function app?

Question

Why are we getting azure platform error - "Exception encountered when listening to event stream. The HTTP/2 connection faulted" for Time triggered function app?

Anirban Roy Choudhury 20

Why are we getting azure platform error - "Exception encountered when listening to event stream. The HTTP/2 connection faulted" for Time triggered function app? We are seeing this is happening intermittently in every few days.

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Khadeer Ali 5,990 Reputation points Microsoft External Staff Moderator

2025-06-16T15:01:29.95+00:00

@Anirban Roy Choudhury ,
Thanks for reaching out.

The error message "Exception encountered when listening to event stream. The HTTP/2 connection faulted" typically indicates issues with the underlying HTTP/2 connection used by Azure Functions. This can happen due to several reasons, including intermittent network issues, timeouts, or resource constraints on the Azure platform.

Given that this occurs intermittently every few days, it likely relates to transient network issues or the function app reaching certain limits, such as execution quotas or outbound connection limits. Implementing retry logic in your function will effectively handle these transient errors.
Anirban Roy Choudhury 20 Reputation points

2025-06-17T09:42:51.1233333+00:00

Thanks @Khadeer Ali, can you see at your end what's the exact reason behind such errors? Network intermittent issues I can understand and we have retries in place.

But, can we know if it's timeout then what's the root cause of timeout? Or if it's reaching limits then what are those limits? Or something else! Looking for more specific answer as this is a Time trigger function app and the function app doesn't require any HTTP calls. Appears to be purely Azure platform issue.
Khadeer Ali 5,990 Reputation points Microsoft External Staff Moderator

2025-06-19T09:38:27.7533333+00:00

@Anirban Roy Choudhury ,

Just checking if you are still facing the issue?

2 answers

Your answer

Khadeer Ali 5,990 Reputation points Microsoft External Staff Moderator

2025-06-16T15:01:29.95+00:00

@Anirban Roy Choudhury ,
Thanks for reaching out.

The error message "Exception encountered when listening to event stream. The HTTP/2 connection faulted" typically indicates issues with the underlying HTTP/2 connection used by Azure Functions. This can happen due to several reasons, including intermittent network issues, timeouts, or resource constraints on the Azure platform.

Given that this occurs intermittently every few days, it likely relates to transient network issues or the function app reaching certain limits, such as execution quotas or outbound connection limits. Implementing retry logic in your function will effectively handle these transient errors.
Anirban Roy Choudhury 20 Reputation points

2025-06-17T09:42:51.1233333+00:00

Thanks @Khadeer Ali, can you see at your end what's the exact reason behind such errors? Network intermittent issues I can understand and we have retries in place.

But, can we know if it's timeout then what's the root cause of timeout? Or if it's reaching limits then what are those limits? Or something else! Looking for more specific answer as this is a Time trigger function app and the function app doesn't require any HTTP calls. Appears to be purely Azure platform issue.
Khadeer Ali 5,990 Reputation points Microsoft External Staff Moderator

2025-06-19T09:38:27.7533333+00:00

@Anirban Roy Choudhury ,

Just checking if you are still facing the issue?

Answer 1

@Anirban Roy Choudhury ,

The error you're seeing — ConnectionAbortedException with "Exception encountered while listening to EventStream. The HTTP/2 connection faulted" — is something that can happen occasionally with Azure Timer-triggered Function Apps.

To clarify, this is not due to your app logic or any HTTP calls from your side. This message appears when the Azure Function host loses its internal connection to the platform's timer scheduler (which runs over HTTP/2 behind the scenes). This can happen due to things like infrastructure maintenance, cold starts, platform updates, or idle timeout on that internal channel.

This is usually a transient platform-level event, and the connection is automatically re-established by the Functions runtime. As long as you're not seeing missed executions, this can generally be considered safe to ignore.

Answer 2

Anirban Roy Choudhury 20

Thanks @Khadeer Ali, makes sense. This shouldn't impact much if they are transient. We can close this query now.

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Why are we getting azure platform error - "Exception encountered when listening to event stream. The HTTP/2 connection faulted" for Time triggered function app?

2 answers

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