Azure TimerTrigger is not working in .NET 7 Isolated Worker Process

Question

I'm trying to trigger an orchestrated function TimerTrigger in .NET 7. Below is the function I created

    [Function(nameof(FunctionSampleTimer))]
    public async Task Run([TimerTrigger("*/5 * * * * *", RunOnStartup = false)] MyInfo myTimer, [DurableClient] DurableTaskClient client, FunctionContext context)
    {
        var instanceid = Guid.NewGuid().ToString();
        var logger = context.GetLogger("TimerFunction");
        logger.LogInformation($"Function Ran. Next timer schedule = {myTimer.ScheduleStatus.Next}");
    } 

The above function is getting triggered once every 5 seconds only for the first time when the project is created, and is not getting triggered again and getting stuck on that "Host lock lease acquired..." line.

Console output shows this:

[2023-02-20T01:26:52.843Z] Azure Functions .NET Worker (PID: 49120) initialized in debug mode. Waiting for debugger to attach...
[2023-02-20T01:26:53.305Z] The next 5 occurrences of the 'FunctionSampleTimer' schedule (Cron: '0,5,10,15,20,25,30,35,40,45,50,55 * * * * *') will be:
[2023-02-20T01:26:53.307Z] 02/19/2023 17:26:55-08:00 (02/20/2023 01:26:55Z)
[2023-02-20T01:26:53.308Z] 02/19/2023 17:27:00-08:00 (02/20/2023 01:27:00Z)
[2023-02-20T01:26:53.309Z] 02/19/2023 17:27:05-08:00 (02/20/2023 01:27:05Z)
[2023-02-20T01:26:53.310Z] 02/19/2023 17:27:10-08:00 (02/20/2023 01:27:10Z)
[2023-02-20T01:26:53.311Z] 02/19/2023 17:27:15-08:00 (02/20/2023 01:27:15Z)
[2023-02-20T01:26:53.312Z]
[2023-02-20T01:26:53.323Z] Host started (775ms)
[2023-02-20T01:26:53.324Z] Job host started
[2023-02-20T01:26:54.472Z] {
[2023-02-20T01:26:54.473Z]   "ProcessId": 49120,
[2023-02-20T01:26:54.474Z]   "RuntimeIdentifier": "win10-x64",
[2023-02-20T01:26:54.475Z]   "WorkerVersion": "1.8.0.0",
[2023-02-20T01:26:54.476Z]   "ProductVersion": "1.8.0-local202209270007\u002B04ccbd8e45bb9017dc30ff5e1343e893a216e173",
[2023-02-20T01:26:54.477Z]   "FrameworkDescription": ".NET 7.0.0",
[2023-02-20T01:26:54.478Z]   "OSDescription": "Microsoft Windows 10.0.22621",
[2023-02-20T01:26:54.479Z]   "OSArchitecture": "X64",
[2023-02-20T01:26:54.480Z]   "CommandLine": "C:\\Users\\swkandhi\\source\\repos\\FunctionTimerTrigger\\FunctionTimerTrigger\\bin\\Debug\\net7.0\\FunctionTimerTrigger.dll --host 127.0.0.1 --port 58647 --workerId e70ddb42-819a-45b2-a17c-dca35392699d --requestId 326e359b-9d29-4105-b2f1-9ef01892ae95 --grpcMaxMessageLength 2147483647"
[2023-02-20T01:26:54.481Z] }
[2023-02-20T01:26:54.493Z] Worker process started and initialized.
[2023-02-20T01:26:55.053Z] Executing 'Functions.FunctionSampleTimer' (Reason='Timer fired at 2023-02-19T17:26:55.0194750-08:00', Id=872452e5-4d71-42ea-a16d-d4790ccf38a2)
[2023-02-20T01:26:57.821Z] Host lock lease acquired by instance ID '00000000000000000000000074E57A56'.

Answer 1

With what you have there for timing (5 * * * * *) I think it means it should run once at the 5 second mark. If you want it to run every 5 seconds you should do this (*/5 * * * * *)

Answer 2

I have observed for every minute and couple of minutes in .NET 7 Isolated Azure Functions with generating the GUID Id, it is working successfully:

Below are my test cases:

For every	1st Run	Next Runs
2 minutes	Yes	Yes
1 minute	Yes	Yes
60 seconds	Yes	Yes
30 Seconds	Yes	No
5 Seconds	Yes	No

---

For every minute:

For every 2 minutes:

For every 60 Seconds:

For every 5 Seconds:

AFAIK, the shortest interval requires at least 60 seconds minimum in the CRON Expression - the same is mentioned in the articles of Hostinger - Cron Job Tutorial.