How do you run N tasks sequentially?

[rpe4a]

I start trying to use conductor. So I only have an one way to run my N tasks sequentially. What I do:

• For example, I have a task 'A' which returns 1000 ids;
• Then I have a task 'B' which return a size of ids = 1000. This 1000 will be my iterator for doWhile tasks;
• Then I have a doWhile task which gets an iterator up to my size of ids = 1000.
• Inside the doWhile's loop
• I have a first task 'C' which takes one id from my task 'A' output (1000 ids);
• I have a second subworkflow 'D' which handles my id that I pick in task 'C' above;
• When the doWhile's loop finish I will collect all results from the output of loop by another task.

You can see the part of workflow here:

Do I do it right? Or somebody has a better idea how can i achive this?

The main problem of the solution above is conductor has input/output limits, so what will happen if I get 1000000 ids? I think I can't take an output of doWhile loop.