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I have a set of Azure functions running in the Azure running over a year already shoveling a huge amounts of data and everything has been fine so far. Last code update was about 3 weeks old and since then again it's processed a lot of data. 2 days ago we suddenly noticed it just stopped working and the Azure function does not start at all. On my dev PC obviously everything works like charm.

  1. Error message #1 Error message 1 I'm using DI in Azure function, I load assembly during function startup and register it to the IoC. The error message is, that the type is not assignable to the interface. Which was clearly nonsense as a. It is b. It's been working this way since forerer. Since I got really desperate I decided to do an experiment and I modified the code (essentially removing the interface), that would prevent the function runtime to throw this particular error and it was replaced by another.

  2. Error message #2 So the Azure function runtime stopped complaining about object inheritance, but now it is displaying a different error message.

    Microsoft.Azure.WebJobs.Extensions.DurableTask: Value cannot be null. (Parameter 'hostConfiguration').

I googled it like crazy, went through DurableTask documentation, but still no ideas. I can restart function, redeploy it, but nothing helps.

My host.json is:

{
  "version": "2.0",
  "functionTimeout": "00:15:00",
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true,
        "maxTelemetryItemsPerSecond": 20,
        "excludedTypes": "Request"
      }
    },
    "console": {
      "isEnabled": true
    }
  },
  "extensions": {
    "http": {
      "routePrefix": ""
    },
    "durableTask": {
      "hubName": "IngressFunctionHubVS"
    }
  }
}

Literally any idea why perfectly running Azure function (it literally ran for ~18 month and processed tenths of GBs of data) can suddenly stop working without any our intervention ( I checked the logs - no one touched it) will be highly appreciated.

Biggles
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  • I would suggest you to raise an Azure support ticket if nothing changes in terms of bits and infrastructure. They can help faster on this issue. Also may not be related but check if `WEBSITE_CONTENTAZUREFILECONNECTIONSTRING` and `WEBSITE_CONTENTSHARE` configuration settings are configured correctly. – user1672994 Feb 12 '21 at 07:54
  • With SaaS it's not only your code that changes. They (Azure) would also update their Function Runtime code and push out "fixes" and "features". These get deployed without you knowing. It's always possible that one such change doesn't agree with your code. Check `activity` and `service health` tabs on portal (this _may not_ contains a log of Azure's deployments, but might give you some hints); and reach out to support. – Kashyap Feb 12 '21 at 15:08

0 Answers0