Executing a loop in a durable functions orchestrator-CodePudding

I want to send several requests to an external endpoint using a loop in a durable functions orchestrator. (I don't want to do it in parallel because of limiting in the external service.)

foreach (input in inputs)
{
    await context.CallActivityAsyncWithRetry("PostRequest", retryOptions, input);
}

From my testing, if the first request fails (after retrying according to my retryOptions) the rest of the foreach fails. Even if I wrap the request in a try/catch which swallows the failure, if the first request fails then the foreach gives up.

foreach (input in inputs)
{
    try
    {
        await context.CallActivityAsyncWithRetry("PostRequest", retryOptions, input);
    }
    catch (Exception e){}
}

Can anyone recommend a way of dealing with this? Create a sub-orchestration for each input? If any of the preceeding requests fails (after retryOptions specified), I still want to try and execute the subsequent requests in the input list.

CodePudding user response：

Loop

foreach (input in inputs)
{
  await PostRequest(dataType input);
}

Then you must have a function to handle two operations, sending a request and handle failure

public async Task PostRequest(dataType input)
{

  try
  {
    await context.CallActivityAsyncWithRetry("PostRequest", retryOptions, input);
  }
   catch (Exception e)
  {
      //handle failure 
      //retry
  }

}

CodePudding user response：

In my view each activity that you call from main trigger function has to handle exception and throw that exception. It is good if you post what is inside postrequest.

From your code currently it will execute one by one ( Means it execute and wait for first one to finish).

 var tasks= new List<Task>();
foreach (input in inputs)
{
   var currentTask = context.CallActivityAsyncWithRetry("PostRequest", retryOptions, input);
  currentTask.ContinueWith(ss => Console.WriteLine(ss) , TaskContinuationOptions.OnlyOnFaulted);
  tasks.Add(currentTask);
}

Task.WaitAll(tasks);