Moving SSL termination to the edge increased the instance of 502 errors

Michael Ottoson michael.ottoson at
Wed Nov 29 04:27:37 UTC 2017

Hi All,

We installed nginx as load balancer/failover in front of two upstream web servers.

At first SSL terminated at the web servers and nginx was configured as TCP passthrough on 443.

We rarely experiences 502s and when it did it was likely due to tuning/tweaking.

About a week ago we moved SSL termination to the edge.  Since then we've been getting daily 502s.  A small percentage - never reaching 1%.  But with ½ million requests per day, we are starting to get complaints.

Stranger: the percentage seems to be rising.

I have more details and a pretty picture here:

Any advice how to squash those 502s?  Should I be worried nginx is leaking?
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