Atomic PUT fails on DNS failover routing policy with 422 validation error

PureCloudPlatformClientV2 handles the DNS routing schema differently than the raw REST gateway. Here’s what I’ve tried so far. First, I constructed the failover payload with record set ID references and priority weight directives, then ran it through the primary endpoint latency checker. The request hit /api/v2/architecture/dns/failover-policies with a 422 response. The health status matrix looked fine, but the max TTL limit triggered a propagation lag rejection. I switched to an atomic PUT operation to force the routing switch, but the gateway still rejects the format verification step.

payload = {"record_set_ids": ["rs_8821", "rs_9942"], "priority_weights": [1, 2], "health_matrix": {"status": "active", "latency_ms": 120}, "ttl_seconds": 300, "geo_verification": "JP-TOKYO"}

The webhook callback to the external DNS provider never fires because the initial validation drops. I need to know how to structure the ttl_seconds and health_matrix fields so the architecture gateway accepts the atomic PUT without throwing a schema mismatch. Also, the audit log endpoint returns empty arrays when the switch fails. What’s the exact JSON shape expected for the priority weight directives? The gateway keeps dropping the PUT request before the traffic redirection triggers anyway. Might be a state drift issue on the provider side but the API doc is vague.

are you sending the If-Match header with the current resource version? the 422 on an atomic PUT almost always hides a concurrency conflict rather than a schema issue. the ttl values look valid, but if the core sees a version mismatch, it drops the payload immediately. you’re likely hitting the distributed lock without the proper etag. make sure your token has routing:edit scope, otherwise the validation layer throws a misleading error code.

you’ll need to grab the latest version from the GET response before firing the update. here’s the payload structure that usually clears the validation error. watch out for the integer casting on maxTtl too, the sdk sometimes sends floats if you’re not careful with the type definition.

{
 "headers": {
 "If-Match": "12",
 "Content-Type": "application/json"
 },
 "body": {
 "id": "policy-uuid",
 "maxTtl": 300,
 "failoverPolicies": []
 }
}

The previous note regarding the ETAG HEADER is accurate. You’re encountering a version lock because the DNS ROUTING schema requires a strict CONCURRENCY CHECK before any atomic PUT. The 422 isn’t a schema rejection, it’s simply the gateway dropping the payload when the RESOURCE VERSION drifts. You’ll need to retrieve the current policy state first, extract the version string, and inject it directly into the request headers. Here’s how the API integration should execute when you patch the TTL LIMIT and priority weights.

curl -X PUT "https://api.mypurecloud.com/api/v2/architecture/dns/failover-policies/${policyId}" \
 -H "Authorization: Bearer $TOKEN" \
 -H "If-Match: ${currentVersion}" \
 -H "Content-Type: application/json" \
 -d '{"ttl_limit": 30, "failover_priority": 1, "health_check_interval": 15}'

Ensure the routing:edit scope remains active on the SERVICE ACCOUNT, otherwise the validation layer will continue returning that same error. The ETAG HEADER manages the rest anyway, just monitor the timeout lag on the secondary node.

the earlier post’s note on the concurrency check is spot on. That version lock is the main culprit here. If you’re driving this update from a Flow using a Lambda Data Action, the 422 usually means the function is trying to write stale state. This happens when the GC resource version drifts while the Lambda is processing the payload.

Fetch the current policy state inside the handler before attempting the PUT. Grab that version field and inject it into the If-Match header. The validation layer drops the payload immediately if the etag doesn’t match the server state.

GenesysRoutingPermission:
 Type: AWS::Lambda::Permission
 Properties:
 FunctionName: !Ref UpdateDNSPolicyFunction
 Action: lambda:InvokeFunction
 Principal: genesys.cloud
 SourceArn: !Sub arn:aws:events:${AWS::Region}:${AWS::AccountId}:event-bus/default

When architecting this in CloudFormation, tying the Lambda permission to the EventBridge bus ensures the trigger has the right context. If the DNS policy changes asynchronously, the Lambda might not have the latest version cached. Adding a step to fetch the resource via GET /api/v2/architecture/dns/failover-policies right before the PUT saves headaches.

The TTL propagation lag mentioned in the first post might be masking the real issue. Sometimes the API returns 422 for TTL limits if the version is off, confusing the error trace. The error message doesn’t always distinguish between a TTL violation and a version mismatch cleanly. If you’re using BYOC trunks, check if the carrier enforces stricter TTL windows. The 422 could be a red herring for a TTL boundary issue.

Also, check the output contract on your Data Action. If the translation map isn’t mapping the version correctly to the header input, the request goes out empty. That’s a common tripwire. flagged the routing:edit scope earlier too. A missing permission often masquerades as a schema validation error, so verify the IAM role attached to the Lambda has that scope.

Are you routing these updates through an EventBridge webhook or calling the API directly from the Lambda?