| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package server |
| |
| import ( |
| "time" |
| ) |
| |
| import ( |
| "github.com/apache/dubbo-kubernetes/pkg/core" |
| util_xds "github.com/apache/dubbo-kubernetes/pkg/util/xds" |
| ) |
| |
| var nackLog = core.Log.WithName("dds-delta").WithName("nack-backoff") |
| |
| type nackBackoff struct { |
| backoff time.Duration |
| util_xds.NoopCallbacks |
| } |
| |
| var _ util_xds.DeltaCallbacks = &nackBackoff{} |
| |
| func NewNackBackoff(backoff time.Duration) util_xds.DeltaCallbacks { |
| return &nackBackoff{ |
| backoff: backoff, |
| } |
| } |
| |
| func (n *nackBackoff) OnStreamDeltaResponse(_ int64, request util_xds.DeltaDiscoveryRequest, _ util_xds.DeltaDiscoveryResponse) { |
| if request.HasErrors() { |
| // When DiscoveryRequest contains errors, it means that a control plane rejected configuration generated by the other control plane |
| // It may happen for several reasons: |
| // 1) Eventual consistency - ex. MeshTrafficPermission, but Mesh for this TrafficPermission is not synced yet. |
| // 2) Config is valid from one control plane side but invalid from the other side - ex. schema is broken |
| // |
| // Second case is especially dangerous because we will end up in a loop. |
| // CP is constantly trying to send a config and other cp immediately rejects the config. |
| // Without this backoff, CP is under a lot of pressure from faulty control plane. |
| // |
| // It is safe to sleep here because OnStreamResponse is executed in the goroutine of a single ADS stream |
| nackLog.Info("config was previously rejected by other control plane. Applying backoff before resending it", "backoff", n.backoff, "nodeID", request.NodeId(), "reason", request.ErrorMsg()) |
| time.Sleep(n.backoff) |
| } |
| } |