title: How to ensure multiple batch jobs can REALLY be parallelized by AWS Step Function
body: <p>noob here.</p>
  <p>I'm using AWS step function's <code>branch</code> to parallelize three batch jobs (Say, job A, B, C) in the same job queue. After initiating the state machine execution, I observed only job A entered <code>RUNNING</code> state while job B, C stayed in <code>RUNNABLE</code> state. And I didn't observe an obvious runtime reduction.</p>
  <p>Could anyone please give me some insights on what parameters I should tweak to make 3 jobs enter <code>RUNNING</code> state all together?</p>
  <p>Thanks in advance!</p>