Azure function code is not invoked

Question

Azure function code is not invoked

Anatolii Zenkovych (CW) 0

Hello

I have a functional app with 3 java functions

Github listener (@HttpTrigger): posts received payload into EventGrid and Kafka listeners
EventGrid listener (@EventGridTrigger)
Kafka listener (@KafkaTrigger)

{
  "scriptFile" : "../plat-jdp-umm-notification-service-1.0.0.jar",
  "entryPoint" : "com.jda.jdp.umm.event.listener.GitHubEventListener.run",
  "bindings" : [ {
    "type" : "httpTrigger",
    "direction" : "in",
    "name" : "req",
    "methods" : [ "POST" ],
    "authLevel" : "FUNCTION"
  }, {
    "type" : "eventGrid",
    "direction" : "out",
    "name" : "outputEvent",
    "topicKeySetting" : "GITHUB_TO_UMM_TOPIC_KEY",
    "topicEndpointUri" : "GITHUB_TO_UMM_TOPIC_ENDPOINT_URI"
  }, {
    "type" : "kafka",
    "direction" : "out",
    "name" : "kafkaOutputEvent",
    "protocol" : "SASLSSL",
    "password" : "%CONFLUENT_KAFKA_PASSWORD%",
    "topic" : "%CONFLUENT_KAFKA_TOPIC_NAME%",
    "authenticationMode" : "PLAIN",
    "username" : "%CONFLUENT_KAFKA_USERNAME%",
    "brokerList" : "%CONFLUENT_KAFKA_BROKER_LIST%"
  }, {
    "type" : "http",
    "direction" : "out",
    "name" : "$return"
  } ]
}

HttpTrigger function registers invocations, but does not invoke the function's code and eventually fails in 30 minutes, that can be seen in the logs.

Screenshot 2025-04-26 at 19.07.21

Similar behavior is observed for event listeners - they are never triggered and fail every 30 minutes.

Screenshot 2025-04-26 at 19.22.08

Since all 3 functions have similar issue pattern, that make me believe there is a common reason, likely configuration issue.

Hope the info I provided is enough. Do you have any idea why this is happening?

Dasari Kamali 335 Reputation points Microsoft External Staff

2025-04-30T05:46:56.1466667+00:00

Hi @Anatolii Zenkovych (CW),

It looks like the issue could be related to function app settings or network/firewall configuration. Since the function is getting stuck before reaching the code, check if there are any mismatched settings between environments. Try scaling up to the Premium plan for better diagnostics and make sure the EventGrid and Kafka bindings are correctly configured in host.json for all environments.
Anatolii Zenkovych (CW) 0 Reputation points

2025-04-30T09:41:13.02+00:00

Yeah, "function app settings or network/firewall configuration" - that's is my assumption as well.

But I compared AppSettings through failing and working apps and did not notice what could be potentially a reason.

Where is "network/firewall configuration" located, so I could check/compare it closely, because I'm not sure what would be the right configuration and how that could be checked?
Dasari Kamali 335 Reputation points Microsoft External Staff

2025-04-30T12:43:55.1466667+00:00

Hi @Anatolii Zenkovych (CW),
You can check the networking settings in the Function App > Networking section in the Azure Portal. Also, compare VNet integration, Access restrictions and Private endpoints across both apps.
Anatolii Zenkovych (CW) 0 Reputation points

2025-04-30T12:52:21.82+00:00

Already checked and don;'t see any significant difference b/w a working networking config and the failing one, at least in the inbound section

and the bad one, no restrictions here:
Dasari Kamali 335 Reputation points Microsoft External Staff

2025-05-02T10:08:39.7666667+00:00

check the outbound connectivity, if the function relies on external endpoints, sometimes outbound restrictions or DNS issues can cause silent failures.
Anatolii Zenkovych (CW) 0 Reputation points

2025-05-02T12:48:57.24+00:00

I created a simple @HttpTrigger function just to log input payload, same problem - the invocation is registered w/o calling my code. There is no outbound binding.

There must be something wrong on MS side ))

1 answer

Your answer

Dasari Kamali 335 Reputation points Microsoft External Staff

2025-04-30T05:46:56.1466667+00:00

Hi @Anatolii Zenkovych (CW),

It looks like the issue could be related to function app settings or network/firewall configuration. Since the function is getting stuck before reaching the code, check if there are any mismatched settings between environments. Try scaling up to the Premium plan for better diagnostics and make sure the EventGrid and Kafka bindings are correctly configured in host.json for all environments.
Anatolii Zenkovych (CW) 0 Reputation points

2025-04-30T09:41:13.02+00:00

Yeah, "function app settings or network/firewall configuration" - that's is my assumption as well.

But I compared AppSettings through failing and working apps and did not notice what could be potentially a reason.

Where is "network/firewall configuration" located, so I could check/compare it closely, because I'm not sure what would be the right configuration and how that could be checked?
Dasari Kamali 335 Reputation points Microsoft External Staff

2025-04-30T12:43:55.1466667+00:00

Hi @Anatolii Zenkovych (CW),
You can check the networking settings in the Function App > Networking section in the Azure Portal. Also, compare VNet integration, Access restrictions and Private endpoints across both apps.
Anatolii Zenkovych (CW) 0 Reputation points

2025-04-30T12:52:21.82+00:00

Already checked and don;'t see any significant difference b/w a working networking config and the failing one, at least in the inbound section

and the bad one, no restrictions here:
Dasari Kamali 335 Reputation points Microsoft External Staff

2025-05-02T10:08:39.7666667+00:00

check the outbound connectivity, if the function relies on external endpoints, sometimes outbound restrictions or DNS issues can cause silent failures.
Anatolii Zenkovych (CW) 0 Reputation points

2025-05-02T12:48:57.24+00:00

I created a simple @HttpTrigger function just to log input payload, same problem - the invocation is registered w/o calling my code. There is no outbound binding.

There must be something wrong on MS side ))

Answer 1

Sina Salam 19,616

Hello Anatolii Zenkovych (CW),

Welcome to the Microsoft Q&A and thank you for posting your questions here.

I understand that your Azure function code is not invoked.

Since all 3 functions and (configuration, Always On, network/firewall, diagnostics) are failing without executing — they are just stuck for 30 minutes and time out — indicating misconfiguration at a more fundamental level. I will suggest the following to resolve the issues:

If @FunctionName is missing or wrong Azure won't load your function. Ensure Java classes have @FunctionName with correct signatures. So that each of your 3 Java methods must have a correct structure. For an example:

  package com.jda.jdp.umm.event.listener;
  import com.microsoft.azure.functions.annotation.*;
  import com.microsoft.azure.functions.*;
  public class GitHubEventListener {
      
      @FunctionName("GitHubHttpListener")
      public HttpResponseMessage run(
          @HttpTrigger(name = "req", methods = {HttpMethod.POST}, authLevel = AuthorizationLevel.FUNCTION)
          HttpRequestMessage<Optional<String>> request,
          final ExecutionContext context) {
          context.getLogger().info("GitHub event received.");
          return request.createResponseBuilder(HttpStatus.OK).body("OK").build();
      }
  }

Your function.json file must match exactly what the Java annotations define. For example, for HTTP trigger:

  {
    "bindings": [
      {
        "authLevel": "function",
        "type": "httpTrigger",
        "direction": "in",
        "name": "req",
        "methods": [ "post" ]
      },
      {
        "type": "http",
        "direction": "out",
        "name": "$return"
      }
    ]
  }

Mismatch between function.json and Java annotations is = no function invocation.

Check your host.json and AppSettings for Java runtime settings - https://learn.microsoft.com/en-us/azure/azure-functions/functions-develop-java
Check Application Insights/Kudu Logs for binding load errors - https://learn.microsoft.com/en-us/azure/azure-functions/functions-monitoring?tabs=applicationinsights#view-logs-in-kudu
Also, in sometimes EventGrid and Kafka triggers require you to enable Extension Bundles in host.json:
```
  "extensionBundle": {
      "id": "Microsoft.Azure.Functions.ExtensionBundle",
      "version": "[2.*, 3.0.0)"
  }
  
```
Without it, EventGrid/Kafka might not bind correctly at runtime.

I hope this is helpful! Do not hesitate to let me know if you have any other questions or clarifications.

Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful.

Anatolii Zenkovych (CW) 0

Thank you for jumping in.

The trigger annotation and function.json are good. Function.json file is built by gradle azureFunctionsPackage task based on the function annotations. But posting it here for clarity:

   @FunctionName("GitHubEventListener")
   public HttpResponseMessage run(
   @HttpTrigger(name = "req",
          methods = {HttpMethod.POST},
          authLevel = AuthorizationLevel.FUNCTION)
   HttpRequestMessage<Optional<String>> request,
   @EventGridOutput(name = "outputEvent",
          topicEndpointUri = "GITHUB_TO_UMM_TOPIC_ENDPOINT_URI",
          topicKeySetting = "GITHUB_TO_UMM_TOPIC_KEY")
   OutputBinding<String> outputEvent,
   @KafkaOutput(name = "kafkaOutputEvent",
          topic = "%CONFLUENT_KAFKA_TOPIC_NAME%",
          brokerList = "%CONFLUENT_KAFKA_BROKER_LIST%",
          protocol = BrokerProtocol.SASLSSL,
          authenticationMode = BrokerAuthenticationMode.PLAIN,
          username = "%CONFLUENT_KAFKA_USERNAME%",
          password = "%CONFLUENT_KAFKA_PASSWORD%")
   OutputBinding<String> kafkaOutputEvent,
   final ExecutionContext context) {
   
   final ApplicationLogger logger = new ApplicationLogger(context);
   try {
   logger.log(
          Level.INFO,
          GITHUB_EVENT_PROCESSING_START
   );
   ....

I'm checking the actual deployment resources under the link - https://plat-jdp-umm-func-test-eus2-02.scm.azurewebsites.net/wwwroot/GitHubEventListener/function.json and don't see any discrepancy (Development Tools -> Advanced Tools -> Site wwwroot). Below are function.json and host.json:
What exactly should I check in AppSettings for Java runtime settings?

Sina Salam 19,616 Reputation points

2025-04-27T15:33:20.17+00:00
Hello Anatolii Zenkovych (CW),

Thank you for your feedback.

My response focused too much on code-level and function.json validation based on similar experience I have seen so far, but missed environment-level (Function App settings, network, runtime issues).

Regarding your explanations, you will need a full environment + network + extension bundle validation, not just code.

Check the following group for guides:

A. Platform and Runtime Checks - https://learn.microsoft.com/en-us/azure/azure-functions/functions-reference-java#settings

Include, App Service Stack, Extension Bundles - https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-event-grid-trigger?tabs=java and enable always ON via Function App > Configuration > General Settings > Always On = true (Required for any trigger that isn’t purely HTTP)

B. Network and Connectivity Checks that no firewall blocking port 9092 or 9093 (depending on Kafka config). - https://learn.microsoft.com/en-us/azure/event-grid/event-handlers#azure-functions

C. Monitoring and Logs and Deployment / Package Issues - https://learn.microsoft.com/en-us/azure/azure-functions/functions-develop-java?tabs=gradle

If possible, temporarily scale up your plan from Consumption to Premium while troubleshooting — gives better logging and less cold start problems.

NOTE: If after all this, functions still do not trigger, do a very simple test:

Create a separate new Function App (clean, no EventGrid, no Kafka).

Deploy only the HTTP Trigger function.

If this also fails, you 100% have a Java worker/runtimes mismatch.

Otherwise, likely a networking/firewall/extension bundle problem for Kafka and EventGrid bindings.

Success.

Anatolii Zenkovych (CW) 0

I believe all the mentioned steps I already checked.. no luck.

The last resort is to drop and create the function from scratch.

I wish the logs narrow down to possible reason of the issue, but they do not:

2025-04-28T14:09:24Z   [Verbose]   AuthenticationScheme: WebJobsAuthLevel was not authenticated.
2025-04-28T14:09:24Z   [Verbose]   Authorization was successful.
2025-04-28T14:09:24Z   [Verbose]   Authorization was successful.
2025-04-28T14:09:24Z   [Information]   Host Status: {
  "id": "plat-jdp-umm-func-test-eus2-02",
  "state": "Running",
  "version": "4.1038.400.1",
  "versionDetails": "4.1038.400-dev.1.0+61ef099a5bb722a8f8d95bc125e823e9cb627a12",
  "platformVersion": "103.0.7.361",
  "instanceId": "ec7c1559d085fbbd94c31dee523bec09364ef8ba28838ed89996d2dbcd283b22",
  "computerName": "lw0ldlwk0000KE",
  "processUptime": 1908150,
  "functionAppContentEditingState": "Unknown",
  "extensionBundle": {
    "id": "Microsoft.Azure.Functions.ExtensionBundle",
    "version": "3.37.0"
  }
}
2025-04-28T14:09:26Z   [Verbose]   AuthenticationScheme: WebJobsAuthLevel was not authenticated.
2025-04-28T14:09:26Z   [Verbose]   Authorization was successful.
2025-04-28T14:09:26Z   [Verbose]   AuthenticationScheme: WebJobsAuthLevel was not authenticated.
2025-04-28T14:09:26Z   [Verbose]   Authorization was successful.
2025-04-28T14:09:27Z   [Verbose]   AuthenticationScheme: WebJobsAuthLevel was not authenticated.
2025-04-28T14:09:27Z   [Verbose]   Authorization was successful.
2025-04-28T14:09:28Z   [Verbose]   AuthenticationScheme: WebJobsAuthLevel was not authenticated.
2025-04-28T14:09:28Z   [Verbose]   Authorization was successful.
2025-04-28T14:09:38Z   [Verbose]   Request successfully matched the route with name 'GitHubEventListener' and template 'api/GitHubEventListener'
2025-04-28T14:09:38Z   [Verbose]   AuthenticationScheme: WebJobsAuthLevel was successfully authenticated.
2025-04-28T14:09:38Z   [Verbose]   Authorization was successful.
2025-04-28T14:09:38Z   [Information]   Executing 'Functions.GitHubEventListener' (Reason='This function was programmatically called via the host APIs.', Id=859ef657-66ec-486c-973b-bdb4b1017d9a)
2025-04-28T14:09:38Z   [Verbose]   Sending invocation id: '859ef657-66ec-486c-973b-bdb4b1017d9a
2025-04-28T14:09:38Z   [Verbose]   Posting invocation id:859ef657-66ec-486c-973b-bdb4b1017d9a on workerId:6e9a5e42-05b7-4ed5-a4f6-c13b8ae9421e
2025-04-28T14:12:31Z   [Verbose]   Request successfully matched the route with name '' and template 'admin/warmup'

That "Executing 'Functions.GitHubEventListener'..." never reaches my code and fails in 30mins.

The interesting part is - I have same function App setup for 6 logical environments, 3 are good and the rest are failing presumably due the same issue.

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Azure function code is not invoked

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