I am sending a request to a custom multicloud plugin from SO via MSB component.

On random basis, SO adapter gets the response as "502 Gateway Error.". In MSB logs, I can see the below error is logged: 

2018/04/30 07:02:21 [error] 43#43: *60948 upstream prematurely closed connection while reading response header from upstream, client: 10.42.190.66, server: , request: "POST /api/multicloud/v0/ATT_EastUS/multipart/createStack/Vfmodule_Ete_1887699d-5c2b-4474-be8c-7655616e06b1 HTTP/1.1", upstream: "http://10.43.99.172:9001/api/multicloud/v0/ATT_EastUS/multipart/createStack/Vfmodule_Ete_1887699d-5c2b-4474-be8c-7655616e06b1", host: "msb-iag.onap-msb:80"
10.42.190.66 - - [30/Apr/2018:07:02:21 +0000] d57ec38e77b8c3a7b3278c52438f2ce2 "POST /api/multicloud/v0/ATT_EastUS/multipart/createStack/Vfmodule_Ete_1887699d-5c2b-4474-be8c-7655616e06b1 HTTP/1.1" 502 request_processing_time:60.542 upstream_response_time:60.541 "" "Apache-HttpClient/4.5 (Java/1.8.0_162)" ""

Even though this error response is captured & returned by MSB, multivimbroker still forward the request to the mulitcloud plugin and get the response.

I modified the multicloud-framework run.sh to use the older runserver command to service the HTTP requests and I didn't see the error now.