Issues while doing load balancing on redash machine

We have deployed multiple redash machine behind ELB,
Issue ::
Whenever we are hitting request from Redash browser the request comes to both the machine, even after doing load balancing .As per my understanding the request should come to one machine only.
But the same thing when I am trying from apache bench , the request is coming to only one machine which is working correctly.It would be great if someone can help on this.

1.nginx.config :

user nginx;
worker_processes 1;

error_log /var/log/nginx/error.log warn;
pid /var/run/;

events {
worker_connections 1024;

http {
include /etc/nginx/mime.types;
default_type application/octet-stream;

log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                  '$status $body_bytes_sent "$http_referer" '
                  '"$http_user_agent" "$http_x_forwarded_for"';

access_log  /var/log/nginx/access.log  main;

sendfile        on;
#tcp_nopush     on;

keepalive_timeout  65;

#gzip  on;

include /etc/nginx/conf.d/*.conf;


2.default.conf :

upstream redash {
server redash:5000;

server {
listen 80 default;

gzip on;
gzip_types *;
gzip_proxied any;
proxy_buffer_size 8k;

location / {
proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $http_x_forwarded_proto;

proxy_pass       http://redash;


I suspect that using the ip_hash policy in Nginx load balancing should solve this problem