Destination Balancing

When a route forwards to multiple destinations (e.g. canary deploys), Vrata picks which destination gets each request. This is level-1 balancing.

Algorithms

WEIGHTED_RANDOM (default)

Pick a destination by weighted random. No stickiness — each request is independent.

{
  "forward": {
    "destinations": [
      {"destinationId": "stable", "weight": 80},
      {"destinationId": "canary", "weight": 20}
    ]
  }
}

WEIGHTED_CONSISTENT_HASH

Pin clients to destinations using a session cookie and consistent hash ring. Disruption is proportional to weight changes.

{
  "forward": {
    "destinationBalancing": {
      "algorithm": "WEIGHTED_CONSISTENT_HASH",
      "weightedConsistentHash": {
        "cookie": {"name": "_vrata_pin", "ttl": "1h"}
      }
    }
  }
}

STICKY

Zero-disruption pinning via Redis. Existing clients always return to the same destination even when weights change. New clients follow the new distribution.

{
  "forward": {
    "destinationBalancing": {
      "algorithm": "STICKY",
      "sticky": {
        "cookie": {"name": "_vrata_pin", "ttl": "1h"}
      }
    }
  }
}

Requires a session store (Redis) in the server config. Falls back to WEIGHTED_CONSISTENT_HASH if Redis is unavailable.

vs Endpoint Balancing