serverless/fdk

trigger method

Closed this issue · 7 comments

mthenw commented

Almost the same as sync call method:

sdk.trigger('sendWelcomeEmail', 'test@exmaple.com', callback)

trigger(name, args, callback)

Parameters:

  • name - string|array - function name(s)
  • args - any type - arguments to pass to called function
  • callback - function - takes err and result. callback parameter informs if trigger has been successfully submitted. It doesn't mean that function has been called.

Currently there is no way to provide configurable retry logic. It's worth to read how it's solved in AWS (http://docs.aws.amazon.com/lambda/latest/dg/retries-on-errors.html).

johncmckim commented

Is there a place for a correlationId as part of the signature? Or should users handle that themselves in args?

nikgraf commented

@mthenw I wonder if this is something we even want to support. I don't know any case where I wouldn't recommend setting up SNS for delayed invocation. Would be nice if we had a helper for that from my perspective.

johncmckim commented

@nikgraf what if you want a result back? This is similar to call which I think is awesome btw. I often want the results back from invoking a Lambda. It's an awesome pattern with GraphQL. i.e. this resolver.

I think there's also a use case for a trigger function. That would use SNS to fire an event and not care about the response.

mthenw commented

@nikgraf AFAIR there is no big difference between invoking lambda async and using SNS for that. In both cases retry logic is similar (if not the same) and isn't configurable.

mthenw commented

@johncmckim

I think there's also a use case for a trigger function. That would use SNS to fire an event and not care about the response.

This is exactly what I mean when created that issue. As I answered above there is no need to use SNS for that.

mthenw commented

Actually I renamed it to trigger for now. It makes more sense.

nikgraf commented

Going to close this now as we creating a new FDK and going to call it emit there