Add a page for monitoring queue latency

[rotated8]

The Sidekiq wiki describes how to create a route that reports queue latency here. Queue latency is a metric useful for managing autoscaling.

This ticket is complete when:

• OE2 has a public route that reports queue latency
• The latency reported covers all queues

[bwatson78]

@rotated8 The code you pointed to reports back either OK or UHOH. I'm guessing you would rather have the current latency in seconds?

[bwatson78]

PR made: #647

[eporter23]

See Brad's link in the description above for testing: root/queue-latency