Hi,
I’m new to nginx. I’m trying to configure nginx with elasticsearch on windows OS. I’m trying to redirect the http request automatically to secondary node(localhost:9201) if primary node(localhost:9200) is down using nginx .Can anyone please help me ? Thanks in advance.
If you want to direct requests based on whether one node is up or down, then you’d need to setup a third node and let it function as the primary entry point for requests. In doing so, you’d be setting up a load balanced solution.
This load balancer node accepts incoming requests and directs them to servers that are listed in the upstream block (as noted in the guide). In the event one of them is down, requests are automatically routed to the next node in the list.
DigitalOcean actually has a basic guide on how to set this up, which I’d recommend taking a look at first.
https://www.digitalocean.com/community/tutorials/how-to-set-up-nginx-load-balancing
events {
worker_connections 1024;
}
http {
upstream localhost {
server localhost:9201;
server localhost:9202;
}
server {
listen 80;
servername localhost:9200;
location / {
proxypass http://localhost;
}
}
}
I have 3 ES nodes. Its supposed to redirect automatically when the primary node is down. Am i doing anything wrong. any advise would be helpful. Thanks in advance.
The best way to set things up would be to separate things out instead of combining them all in to one single file.
For example, nginx.conf at the location below.
/etc/nginx/nginx.conf
The above file would have something such as (for a more complete configuration):
user nginx nginx;
worker_processes 1;
worker_priority -10;
worker_rlimit_nofile 260000;
timer_resolution 100ms;
pcre_jit on;
events {
worker_connections 10000;
accept_mutex off;
accept_mutex_delay 200ms;
use epoll;
}
http {
map_hash_bucket_size 128;
map_hash_max_size 4096;
server_names_hash_bucket_size 128;
server_names_hash_max_size 2048;
variables_hash_max_size 2048;
index index.php index.html index.htm;
include mime.types;
default_type application/octet-stream;
charset utf-8;
sendfile on;
sendfile_max_chunk 512k;
tcp_nopush on;
tcp_nodelay on;
server_tokens off;
server_name_in_redirect off;
keepalive_timeout 5;
keepalive_requests 500;
lingering_time 20s;
lingering_timeout 5s;
keepalive_disable msie6;
gzip on;
gzip_vary on;
gzip_disable "MSIE [1-6]\.";
gzip_static on;
gzip_min_length 1400;
gzip_buffers 32 8k;
gzip_http_version 1.0;
gzip_comp_level 5;
gzip_proxied any;
gzip_types text/plain
text/css
text/xml
application/javascript
application/x-javascript
application/xml
application/xml+rss
application/ecmascript
application/json
image/svg+xml;
client_body_buffer_size 256k;
client_body_in_file_only off;
client_body_timeout 10s;
client_header_buffer_size 64k;
client_header_timeout 5s;
client_max_body_size 50m;
connection_pool_size 512;
directio 4m;
ignore_invalid_headers on;
large_client_header_buffers 8 64k;
output_buffers 8 256k;
postpone_output 1460;
proxy_temp_path /etc/nginx/cache/proxy;
request_pool_size 32k;
reset_timedout_connection on;
send_timeout 10s;
types_hash_max_size 2048;
open_file_cache max=50000 inactive=60s;
open_file_cache_valid 120s;
open_file_cache_min_uses 2;
open_file_cache_errors off;
open_log_file_cache max=10000 inactive=30s min_uses=2;
include /etc/nginx/sites-available/*.conf;
}
Now above, you’ll see:
include /etc/nginx/sites-available/*.conf;
That’s saying that NGINX should include all configuration files in the ./sites-available directory, which is where you’d place your website specific configuration (your server blocks) – i.e.
server {
....
}
Now, for a full proxy setup, create a file in /etc/nginx/sites-available/ named something like
/etc/nginx/sites-available/mywebsite.conf
Inside that file, paste in:
upstream backend {
server 10.111.222.333;
server 11.111.222.333;
}
server {
listen 80;
server_name yourdomain.com www.youdomain.com;
location / {
proxy_pass http://backend;
proxy_connect_timeout 59s;
proxy_send_timeout 600;
proxy_read_timeout 600;
proxy_buffer_size 64k;
proxy_buffers 16 32k;
proxy_busy_buffers_size 128k;
proxy_temp_file_write_size 64k;
proxy_pass_header Set-Cookie;
proxy_redirect off;
proxy_set_header Accept-Encoding '';
proxy_ignore_headers Cache-Control Expires;
proxy_set_header Referer $http_referer;
proxy_set_header Host $host;
proxy_http_version 1.1;
proxy_hide_header X-Powered-By;
proxy_set_header Cookie $http_cookie;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-Host $host;
proxy_set_header X-Forwarded-Server $host;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_no_cache $http_pragma $http_authorization;
proxy_cache_bypass $http_pragma $http_authorization;
proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504 http_404;
}
}
In the upstream block, you need to use IP’s or Hostnames, as I’ve showcased above. You can’t use localhost since all your servers are not actually served by the same droplet. You should also use a name for the upstream other than localhost since that’s a reserved name in most all configurations.
Once you have everything configured with your IP’s / Ports (simply replace my IP’s in the upstream block with your own), you’d need to restart NGINX.