Given configuration sets up an NGINX server to route incoming requests to one of the backend InfluxD

The given configuration sets up an NGINX server to route incoming requests to one of the backend InfluxDB servers specified in the upstream block. Here's a detailed breakdown of how this works:

Steps to Route Data Using This Configuration:

1. Define the Backend Servers:

   • The upstream influxdb block lists three backend InfluxDB servers:
     • 172.16.35.186:8086
     • 172.16.35.187:8086
     • 172.16.35.188:8086
   • NGINX will distribute the incoming requests among these servers based on the default load-balancing strategy (round-robin).

2. Listen on Port 8086:

   • The server block configures NGINX to listen for incoming requests on port 8086 at the IP address 192.168.2.43.

3. Forward Requests to Backend:

   • The proxy_pass http://influxdb; directive forwards all requests to the influxdb upstream block, which distributes them to the configured backend servers.

4. Set Headers for Proxied Requests:

   • The following proxy_set_header directives set appropriate headers:
     • Host $host: Passes the original Host header from the client.
     • X-Real-IP $remote_addr: Adds the client's actual IP address.
     • X-Forwarded-For $proxy_add_x_forwarded_for: Chains the client IP for tracing purposes.
     • X-Forwarded-Proto $scheme: Indicates whether the original request was made over HTTP or HTTPS.

What Happens When Data is Routed:

• Client Request: When a client sends a request to 192.168.2.43:8086, NGINX intercepts it.
• Load Balancing: NGINX forwards the request to one of the three InfluxDB servers in the upstream influxdb block using the round-robin load-balancing method.
• Backend Response: The chosen InfluxDB server processes the request and sends the response back to NGINX.
• Client Response: NGINX then relays the response back to the client.

Verifying Configuration:

1. Test Configuration: Run the following command to ensure the NGINX configuration syntax is correct:

   nginx -t

2. Restart NGINX: If the configuration is valid, reload or restart NGINX:

   nginx -s reload

3. Check Logs: Check the NGINX logs (error_log or access_log) for any errors or routing issues.

Enhancements (Optional):

• Health Checks: Add health checks for backend servers to ensure traffic isn't sent to unavailable servers:

  nginx

  upstream influxdb { server 172.16.35.186:8086 max_fails=3 fail_timeout=30s; server 172.16.35.187:8086 max_fails=3 fail_timeout=30s; server 172.16.35.188:8086 max_fails=3 fail_timeout=30s; }

• Sticky Sessions: If you need requests from the same client to go to the same server, enable sticky sessions:

  nginx

  upstream influxdb { ip_hash; server 172.16.35.186:8086; server 172.16.35.187:8086; server 172.16.35.188:8086; }

This setup ensures smooth routing of requests to your InfluxDB instances while leveraging NGINX for load balancing and failover.