This is a followup to the concerns raised in an earlier thread titled "Issue with Routing Release v149-151". That thread notes that there is no issue with those routing releases.
The underlying 502 errors appear to be an issue with how the nginx server on Cloud Controller handles keep alive connections. The root cause is unknown and investigation is underway.
What does this mean for you?
If you set the value of router.max_idle_connections to zero then you will see no issues. However, setting that property provides performance enhancements to traffic going to hosted apps. If the performance gains are important enough to outweigh intermittent 502 errors from CC API requests, then you can consider enabling router.max_idle_connections.
CAPI Project Lead