Dual-stream

Retrying a failed push against an alternate domain (see Ensure high availability of streaming services) helps when a single push fails outright. For streams that need continuous protection against a degraded connection or a mid-broadcast drop, use dual-stream high availability instead.

With dual-stream high availability, you push the same content to two independent streaming keys bound to the same channel and user ID: one over a primary domain, one over a backup domain. Media Gateway keeps the primary stream active and the backup on standby, and can automatically promote the backup if the primary stream fails or degrades.

Set up dual streamingCopy Anchor Link

1. Create two custom domains, one with domainType: 0 (primary) and one with domainType: 1 (backup). For more information, see RTMP and RTMPS streaming.
2. Create two streaming keys bound to the same channel and uid.
3. Enable dualStreaming for your project using adaptive mode (switchStrategy: 2), so Media Gateway also promotes the backup stream when the primary degrades in quality:

curl --request PUT \
  --url https://api.agora.io/${region}/v1/projects/${appId}/rtls/ingress/appconfig \
  --header 'Content-Type: application/json' \
  --header 'Authorization: Basic XXXXXX' \
  --data '{
    "settings": {
      "dualStreaming": {
        "enabled": true,
        "switchStrategy": 2,
        "qualityThreshold": {
          "freezeRate": {
            "high": 30,
            "low": 5
          }
        },
        "adaptiveSwitchPolicy": {
          "windowCount": 5,
          "degradeCount": 3,
          "recoverCount": 3,
          "takeoverCount": 3,
          "cooldownMs": 30000
        }
      }
    }
  }'

4. Push to both domains at the same time, using the matching streaming key for each:

rtmps://primary-live.example.com/{app}/{primaryStreamKey}
rtmps://backup-live.example.com/{app}/{backupStreamKey}

Switch strategiesCopy Anchor Link

Set switchStrategy in the dualStreaming request body to control how Media Gateway decides when to promote the backup stream:

With adaptive mode, quality is judged by freezeRate (in per-mille, so 30 means 3.0%) against a rolling window of samples. The defaults are:

Each protected source also counts as two streams against your concurrent task limit: one for the primary push and one for the backup, even while the backup is on standby.