Optimizing delivery of LL-HLS with NGINX

[mauricioabreu]

My latest question here was about how to use NGINX along with OvenMediaEngine.

Today, I’m sharing my configuration here. It might help others bootstrap their own configurations.

worker_processes  auto;

pid        /var/run/nginx.pid;

events {
    worker_connections  1024;
}

http {
    proxy_cache_path /opt/nginx_cache levels=1:2 keys_zone=cache_zone_one:10m;
    log_format main 'time="$time_iso8601" remote_addr="$remote_addr" req="$request" status="$status" '
                  'req_time="$request_time" bytes_sent="$body_bytes_sent" up_cache_status="$upstream_cache_status" '
                  'up_status="$upstream_status" up_addr"$upstream_addr" up_resp_time="$upstream_response_time" '
                  'ref="$http_referer" ua="$http_user_agent" scheme="$scheme"';
    access_log /dev/stdout main;

    upstream origin {
        server origin:3333;
        keepalive 64;
    }

    server {
        listen       80;
        server_name  localhost;
        proxy_ignore_headers "vary";
        proxy_hide_header "access-control-allow-origin";
        proxy_hide_header "access-control-allow-credentials";
        proxy_hide_header "access-control-allow-methods";
        proxy_hide_header "access-control-allow-headers";

        location ~ ^/.*.m3u8 {
            proxy_cache_key $request_uri;
            proxy_set_header Connection "";
            proxy_http_version 1.1;
            proxy_cache cache_zone_one;
            proxy_cache_lock on;
            add_header X-Cache-Status $upstream_cache_status;

            proxy_pass http://origin;
        }

        location ~ ^/.*.m4s {
            proxy_cache_key $request_uri;
            proxy_set_header Connection "";
            proxy_http_version 1.1;
            proxy_cache cache_zone_one;
            proxy_cache_lock on;
            add_header X-Cache-Status $upstream_cache_status;

            proxy_pass http://origin;
        }
    }
}

This configuration should have http2, but enabling locally is not straightforward - use mkcert

For those who are already familiar with LL-HLS and NGINX, what other settings or approaches would you recommend?

[naanlizard]

Are you certain you want to have your upstream connect to port 3333? That's typically the WebRTC port, not LLHLS

Can you explain your thinking with some comments inline?

I'd also say your logging seems excessive, but perhaps that's what you want for debugging

[maruf-cs]

I noticed that the session (Yellow) appears to be unique for each user. By using "proxy_cache_key $request_uri;" the cache hit ratio decreases significantly. I'm trying to understand more about this session behavior—what exactly is it, and how is it managed for each user? If I skip the session in the proxy server, the stream doesn’t play smoothly. Could anyone provide some guidance on how to handle this efficiently?

[naanlizard]

I'm also curious about how the session key works.

I did find this guide to ignoring the session number but it sounds like you already tried that, how did you implement it?

How are you tracking your cache hit rate?

[getroot]

When there is an edge behind the origin, set LLHLS OriginMode to true. The session_key will be deleted, so it can be cached on the edge.

OvenMediaEngine/misc/conf_examples/Origin.xml

Line 359 in cdc0b62

<OriginMode>true</OriginMode>

<LLHLS>
	<OriginMode>true</OriginMode>

[maruf-cs]

I'm also curious about how the session key works.

I did find this guide to ignoring the session number but it sounds like you already tried that, how did you implement it?

How are you tracking your cache hit rate?

I tried manually parsing and ignoring the session parameter for the cache key, but it wasn’t the right approach. As for tracking the cache hit rate, I'm not actually tracking it directly at the moment. Instead, I'm monitoring the bandwidth IN and OUT ratio of the server as a rough indicator of how well the cache is performing.