DescribeJobFlows returns a list of job flows that match all of the supplied parameters. The parameters can include a list of job flow IDs, job flow states, and restrictions on job flow creation date and time.
Regardless of supplied parameters, only job flows created within the last two months are returned.
If no parameters are supplied, then job flows matching either of the following criteria are returned:
RUNNING
, WAITING
, SHUTTING_DOWN
, STARTING
Amazon Elastic MapReduce can return a maximum of 512 job flow descriptions.