Multi-Server and CDN

Add independently licensed Engine servers, then select which nodes may deliver playback.

Add a Server

1. Open Server → Add Server.
2. Enter SSH, public address, ports, primary interface, and measured usable egress.
3. Install or register the node.
4. Activate its license and verify health, RPC, source access, and playback.

Enable CDN Delivery

1. Enable CDN in Settings → System Settings.
2. Enable CDN Service on eligible servers.
3. Set measured Usable Egress Capacity.
4. Select Auto or an ordered CDN list in the Package or custom User policy.
5. Test every eligible node.

CDN Service controls whether a server may cache content hosted on other servers. It does not affect playback or CDN pulls of its own source content. Keep it off on source servers unless they also need to cache other servers’ content. Turning it off blocks new cache assignments; existing sessions continue normally. Bandwidth and license limits still apply.

Changed in Engine 1.0.4+

Load Balancing and Cache

Automatic assignment uses healthy, licensed nodes below their connection and bandwidth limits. It does not move existing sessions.

For HLS, DASH, and HTTP-TS, new assignments prefer nodes that already cache the channel. Engine adds another cache when existing nodes lack capacity. Engine leaves 10% of its effective egress capacity for cache expansion and 5% for traffic variation. Set Usable Egress Capacity to the bandwidth the server can sustain, including other traffic on its primary interface.

When several healthy nodes cache the same channel, new viewers prefer a stable order of those nodes. As demand falls and existing sessions end, unused replicas can become idle and be released. Servers still serving viewers or downstream caches remain active. User server restrictions and available capacity may require several replicas. Adding an empty server does not move healthy cached channels to it.

Changed in Engine 1.0.3+

Cache nodes prefer a healthy upstream cache with spare capacity, then try the Origin. Live segment requests reuse a working upstream while it remains available and has capacity. A cached playlist alone does not make a node a segment upstream. An Engine Origin applies its own capacity limits, so more than one cache may pull directly from it when capacity allows. Cache chains are limited to five levels after the Origin. Active downstream caches keep their upstream relay in use; idle relays are released after a grace period.

Changed in Engine 1.0.3+

HLS/DASH Live Prefetch fetches new live objects on CDN nodes. Live Stream tmpfs Cache uses memory-backed storage for supported live cache data and falls back to disk. HTTP-TS is not prefetched.

If assignment fails, check global CDN settings, server CDN state, Package/User selection, health, public address, license limits, routing, TLS, and storage—in that order.