| // Copyright 2017 The etcd Authors |
| // |
| // Licensed 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 ordering |
| |
| import ( |
| "errors" |
| "sync" |
| "time" |
| |
| "github.com/coreos/etcd/clientv3" |
| ) |
| |
| type OrderViolationFunc func(op clientv3.Op, resp clientv3.OpResponse, prevRev int64) error |
| |
| var ErrNoGreaterRev = errors.New("etcdclient: no cluster members have a revision higher than the previously received revision") |
| |
| func NewOrderViolationSwitchEndpointClosure(c clientv3.Client) OrderViolationFunc { |
| var mu sync.Mutex |
| violationCount := 0 |
| return func(op clientv3.Op, resp clientv3.OpResponse, prevRev int64) error { |
| if violationCount > len(c.Endpoints()) { |
| return ErrNoGreaterRev |
| } |
| mu.Lock() |
| defer mu.Unlock() |
| eps := c.Endpoints() |
| // force client to connect to given endpoint by limiting to a single endpoint |
| c.SetEndpoints(eps[violationCount%len(eps)]) |
| // give enough time for operation |
| time.Sleep(1 * time.Second) |
| // set available endpoints back to all endpoints in to ensure |
| // the client has access to all the endpoints. |
| c.SetEndpoints(eps...) |
| violationCount++ |
| return nil |
| } |
| } |