持久功能SubOrchestrator不返回

Question

I have a durable function that defers to sub orchestrators, something like this:

[FunctionName("Trigger")]
public static async Task OrchestrationFunctionFromHttpAsync(
    [OrchestrationTrigger]DurableOrchestrationContext context,
    ILogger log)
{
    var firstResult = await context.CallSubOrchestratorAsync<int>("FirstFunction", null);
    var secondResult = await context.CallSubOrchestratorAsync<int>("SecondFunction", null);
}

The first sub-orchestrator completes successfully, but the execution doesn't return to the orchestration function, so the second sub-orchestrator never gets called. How would I even investigate why this is happening?

Answer 1

This seems to be a bug in the durable functions framework. I faced the same issue with a Javascript orchestrator that would exit as soon as the subOrchestration finished and without executing the code after the subOrchestration. The issue seems to stem from a bug where the durable functions framework cannot retrieve the subOrchestration's output from the saved state if the subOrchestration did not have a defined instanceId. So by specifying a instanceId the code will execute fine.

My orchestrator code that was failing looked like this:

var reboot_result = yield context.df.callSubOrchestrator('reboot_orchestrator',reboot_input);
context.log('this is the next line after subOrch call which will not get called');

The context.log would never get called. So I manually specify an instanceId on the callSubOrchestrator and this fixed the issue :)

const child_id = context.df.instanceId + ":0"; //create instanceId
var reboot_result = yield context.df.callSubOrchestrator('reboot_orchestrator',reboot_input,child_id);
context.log('this is the next line after subOrch call and now it gets called properly');

Here's the link to the Github bug report: https://github.com/Azure/azure-functions-durable-js/issues/54