在Heroku上偶尔出现“ http：代理错误：读取tcp：I / O超时” [关闭]

Question

I'm getting this error sporadically on Heroku:

Proxy service:

Dec 27 14:53:05 betalo-turnpike-production app/web.2:  { [...] } 

Dec 27 14:53:08 my-proxy app/web.2:  {
    "level":"error",
    "ts":"2018-12-27T14:53:07.771Z",
    "caller":"httputil/reverseproxy.go:393","msg":"http: proxy error: read tcp [REDACTED]->[REDACTED]: i/o timeout",
    "stacktrace":"log.(*Logger).Output

    /app/tmp/cache/go1.11.4/go/src/log/log.go:172
log.(*Logger).Printf
    /app/tmp/cache/go1.11.4/go/src/log/log.go:179
net/http/httputil.(*ReverseProxy).logf
    /app/tmp/cache/go1.11.4/go/src/net/http/httputil/reverseproxy.go:393
net/http/httputil.(*ReverseProxy).defaultErrorHandler
    /app/tmp/cache/go1.11.4/go/src/net/http/httputil/reverseproxy.go:158
net/http/httputil.(*ReverseProxy).defaultErrorHandler-fm
    /app/tmp/cache/go1.11.4/go/src/net/http/httputil/reverseproxy.go:166
net/http/httputil.(*ReverseProxy).ServeHTTP
    /app/tmp/cache/go1.11.4/go/src/net/http/httputil/reverseproxy.go:234
net/http/httputil.(*ReverseProxy).ServeHTTP-fm
    [...]
net/http.HandlerFunc.ServeHTTP
    /app/tmp/cache/go1.11.4/go/src/net/http/server.go:1964
net/http.serverHandler.ServeHTTP
    /app/tmp/cache/go1.11.4/go/src/net/http/server.go:2741
net/http.(*conn).serve
    /app/tmp/cache/go1.11.4/go/src/net/http/server.go:1847"} 

Dec 27 14:53:08 my-proxy app/web.2:  { [...] "status":502} 

Dec 27 14:53:09 my-proxy heroku/router:  sock=backend at=error code=H18 desc="Server Request Interrupted" [...] dyno=web.2 connect=0ms service=4453ms status=503 protocol=https 

Called service:

Dec 27 14:53:05 my-service app/web.1:  { [...] } 
Dec 27 14:53:08 my-service app/web.1:  { [...] "status":400} 
Dec 27 14:53:08 my-service heroku/router:  sock=client at=warning code=H27 desc="Client Request Interrupted" [...] dyno=web.1 connect=1ms service=2995ms status=499 bytes=0 protocol=https 

Anyone knows what is wrong?

Answer 1

externally, my proxy returns 502 (upstream gone away) my proxy talks to my service which returns 400 (client error) the router layer returns 499 (client closed request)

what is happening is that the external caller is dropping the connection while the "my service" is preparing a result to go back on the connection to "my proxy". This means that the socket drops from the "my proxy" side.

The router at the my service side logs a 499 and so the app logs a 400

There is nothing wrong with your code. The external clients using your web service are dropping their connections early and this is how the application responds in logs