see: https://gryzli.info/2018/03/05/nginx-cannot-assign-requested-address/

S3-Nginx-Proxy.md

@@ -3,7 +3,7 @@ It's a common concept to put a proxy in front of S3 that handles requests. Nginx
 ### Example Nginx config
 
 ```
-upstream seaweedfs { server localhost:8333 fail_timeout=0; }
+upstream seaweedfs { server localhost:8333 fail_timeout=0; keepalive 20;}
 
 server {
 	listen 443 ssl;