Duration and metrics/collect task

[kalantar]

An experiment expresses duration as:

...
duration:
  intervalSeconds: 5
  iterationsPerLoop: 10
  maxLoops: 15
...

A lower bound for execution time is then itervalSeconds * iterationsPerLoop * maxLoops. However, actual running time is also related to task execution. Of these, metrics/collect has a big influence. Our first experiment has the duration values all set to 1 but still takes some time to complete because of the task.

Using builtin metrics, it is easy to specify duration poorly. iterationsPerLoop should probably always be 1. If the task is a start task, maxLoops should also be 1. If a loop task, should be something else.

Is there anything we can do to make this easier and clearer?

[sriumcp]

The only real reason why we kept both loops and iterations was backwards compatibility.

With migration to v2beta1, we should drop iterations in favor of loops (i.e., just keep maxLoops). Of course, if there are no loop actions, the only thing the controller would do, during each loop, would be to talk to analytics. If there are loop actions, additionally, during each loop, the controller would as usual launch those actions also.

We can explain intervalSeconds as the minimum duration between loops (we can rename it as minIntervalBetweenLoops if we want to). The duration can be longer depending upon the amount of time taken by loop actions to execute.

[sriumcp]

Perhaps we should convert this into a v2beta1 issue (for 0.8 project)?

[kalantar]

Yes, can convert to issue; created as discussion because I didn't have a solution in mind.

[kalantar]

If we are going to drop one of the notions of iteration and loop; which term makes more sense to keep? I am more in favor of keeping iteartion (and iteration handlers) but not sure. Maybe step would be better?

[sriumcp]

I really think these are all the same concepts, and convey the same meaning.

We already have the concept of a loop action, so I see no reason to not keep it.

My preference would be to go with maxLoops (instead of iteration actions or step actions which calls for handler level changes, instead of etc3 level changes).

Besides loop has 4 fewer characters as iteration, so less typing !!!

[kalantar]

created issue #968