Riemann Aws ELB: send 0 metric on empty result

[krakatoa]

Hi, with this PR we fill empty datapoints for ELB metrics with zeroes (they have more value than "?" or "null").
Thanks! 👍

[jamtur01]

Can you elaborate why they are more useful? Just because they are at least integers?

[krakatoa]

According ELB Dimensions and Metrics doc (http://docs.aws.amazon.com/AmazonCloudWatch/latest/DeveloperGuide/elb-metricscollected.html), every metric reports a value whenever it is "a nonzero value" or "there are registered instances". So we can fill those zeroes on our side without affecting any of these metrics.
Where's the benefit ? We will see integers instead of "?" in the dashboard. If we want to make any calculation on Riemann server, we don't need to add time windows with a default. That's all.

[jamtur01]

Cool! Thanks!