How to persist state in Azure Function (the cheap way)?

Durable entities are now available to handle persistence of state.

https://docs.microsoft.com/en-us/azure/azure-functions/durable/durable-functions-entities?tabs=csharp

This is old thread but worth sharing the new way to handle state in Azure function.

Now we have the durable function approach from Microsoft itself where we can maintain the function state very easily and effectively. Please refer the below documentation from MS.

https://docs.microsoft.com/en-us/azure/azure-functions/durable/durable-functions-overview

There are a couple options - I'd recommend that you store your state in a blob.

You could use a blob input binding to read global state for every execution, and a blob output binding to update that state.

You could also remove the timer trigger and use queues, with the state stored in the queue message and a visibility timeout on the message to set the schedule (i.e next execution time).

Finally, you could use a file on the file system, as it is shared across the function app.

If you can accept the possibility of data loss and only care at the instance level, you can:

• maintain a static data structure
• write to instance local storage