longpolling-computerun

[devaKumaraswamy]

computeRun was not taking advantage of the long polling in compute service. To fix this:

• must pass a query like the sample below to the jobState to use the long polling.
• must handle the 304 returned by long polling

{ newState: 'Completed', timeout: 2}
The timeout is in seconds. 

This fix will improve the performance.

[devaKumaraswamy]

The fix does not handle the case of the job failing before the first state check. The state end point keeps returning 304. To handle this have to remove newState and instead use headers['If-None-Match'] = etag.

[devaKumaraswamy]

still need to allow checkStatus to set a new status value for convenience of post processing