Azure function activity function being terminad because another function reaches timeout limit

Question

Azure function activity function being terminad because another function reaches timeout limit

Neščivera Ján (ERNI) 5

We have an Nodejs Azure functions app (Node 20, programing model v3) that contains multiple functions - some http triggered, some event hub trigerred, and some durable functions with orchestrators and activities.

We noticed that ocassionally one of or activity functions fails with error:

Worker channel is shutting down. Aborting function. Reason: Timeout value of 00:10:00 was exceeded by function: other-eventhub-function Timeout value of 00:10:00 was exceeded by function: other-eventhub function

It seem like our activity function is being killed because some other unrelated function (in the same function app) timed out. Is that possible? Should not the function executions be isolated?

Pravallika KV 8,110 Reputation points Microsoft External Staff Moderator

2026-02-05T09:02:15.3966667+00:00
Hi @Neščivera Ján (ERNI),

Thanks for reaching out to Microsoft Q&A.

Yes, that's expected behavior. Functions in the same Node.js Function App are not process-isolated. All functions share the same Node worker. If any function for example: an Event Hub trigger exceeds the 10-minute timeout, the Functions host shuts down the worker, which aborts all other in-flight executions, including unrelated Durable activity functions.

Durable Functions do not provide process isolation for activities; activities are regular functions and follow the same worker lifetime rules.

If you need isolation, you can try below steps:

Keep Event Hub processing under the timeout

Increase/remove functionTimeout (Premium/Dedicated only)

Or isolate heavy/long-running functions into a separate Function App or move long-running work into smaller Durable activities
Neščivera Ján (ERNI) 5 Reputation points

2026-02-05T09:13:43.5266667+00:00

Just out of curiosity - if our functions would be developed using .NET with isolated worker model, would that be also the case, or then the execution of each function would be trully independent (aka. one function's timeout would not abort other in-flight functions)?
Pravallika KV 8,110 Reputation points Microsoft External Staff Moderator

2026-02-05T09:42:55.8266667+00:00

With .NET isolated worker model, each function still runs in the same Function App process, but the .NET isolated worker is a separate process from the Functions host.

Timeouts in one function do not automatically kill the entire worker like in Node.js. So, if one function times out, it generally does not abort other in-flight functions. Each invocation is much more isolated.

Your answer

Pravallika KV 8,110 Reputation points Microsoft External Staff Moderator

2026-02-05T09:02:15.3966667+00:00

Hi @Neščivera Ján (ERNI),

Thanks for reaching out to Microsoft Q&A.

Yes, that's expected behavior. Functions in the same Node.js Function App are not process-isolated. All functions share the same Node worker. If any function for example: an Event Hub trigger exceeds the 10-minute timeout, the Functions host shuts down the worker, which aborts all other in-flight executions, including unrelated Durable activity functions.

Durable Functions do not provide process isolation for activities; activities are regular functions and follow the same worker lifetime rules.

If you need isolation, you can try below steps:

Keep Event Hub processing under the timeout

Increase/remove functionTimeout (Premium/Dedicated only)

Or isolate heavy/long-running functions into a separate Function App or move long-running work into smaller Durable activities
Neščivera Ján (ERNI) 5 Reputation points

2026-02-05T09:13:43.5266667+00:00

Just out of curiosity - if our functions would be developed using .NET with isolated worker model, would that be also the case, or then the execution of each function would be trully independent (aka. one function's timeout would not abort other in-flight functions)?
Pravallika KV 8,110 Reputation points Microsoft External Staff Moderator

2026-02-05T09:42:55.8266667+00:00

With .NET isolated worker model, each function still runs in the same Function App process, but the .NET isolated worker is a separate process from the Functions host.

Timeouts in one function do not automatically kill the entire worker like in Node.js. So, if one function times out, it generally does not abort other in-flight functions. Each invocation is much more isolated.

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Azure function activity function being terminad because another function reaches timeout limit

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