An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Results Queue Service


The Results Queue Service functions to allow other WATERS services to process results asynchronously. In a typical service request, the caller must wait for the service results to return before proceeding with further actions.

Result Queue Service Modal Illustration

When processing large requests the time required for processing may cause server timeouts. The Results Queue Service is an alternative allowing callers to submit requests to a queue where processing is undertaken asynchronously. Results are then placed into the queue for pickup. Using an identification code, the user may query the Results Queue Service to either determine if processing is complete or fetch completed results.

Result Queue Service Threaded Illustration

Top of Page

Input Parameters

The Results Queue Service has two modes, FETCH HTTP and GET STATUS which either attempt to return the queued service results or simply checks the status of processing service results.

Parameter Datatype Description
pQueueUniqueID String The service-defined identification number for a queued process. Obtained from a service call utilizing the optQueueResults parameter.
pQueueUserID String The alternative user-defined identification string assigned to a queued process. Obtained from a service call utilizing the optQueueID parameter.
pAction String Keyword of either FETCH HTTP or GET STATUS.

Additional parameters specific to HTTP services are listed in the WATERS HTTP Services documentation.

Top of Page

Output Return Object

Get Status Call

Property Datatype Description
queue_status String

Status value indicating state of queued job.

  • processing
  • complete
  • not found

Top of Page

HTTP Service

Resource Location

Top of Page

Database Service

Schema Resource
WATERS10 WATERS_SERVICES results_queue_service.retrieve_results

Top of Page


Version: 3.0 - Released: February 4, 2014

  • Initial Release of HTTP Services.

Top of Page