khenaidoo | ffe076b | 2019-01-15 16:08:08 -0500 | [diff] [blame^] | 1 | // Copyright 2017 The etcd Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package ordering |
| 16 | |
| 17 | import ( |
| 18 | "errors" |
| 19 | "sync" |
| 20 | "time" |
| 21 | |
| 22 | "github.com/coreos/etcd/clientv3" |
| 23 | ) |
| 24 | |
| 25 | type OrderViolationFunc func(op clientv3.Op, resp clientv3.OpResponse, prevRev int64) error |
| 26 | |
| 27 | var ErrNoGreaterRev = errors.New("etcdclient: no cluster members have a revision higher than the previously received revision") |
| 28 | |
| 29 | func NewOrderViolationSwitchEndpointClosure(c clientv3.Client) OrderViolationFunc { |
| 30 | var mu sync.Mutex |
| 31 | violationCount := 0 |
| 32 | return func(op clientv3.Op, resp clientv3.OpResponse, prevRev int64) error { |
| 33 | if violationCount > len(c.Endpoints()) { |
| 34 | return ErrNoGreaterRev |
| 35 | } |
| 36 | mu.Lock() |
| 37 | defer mu.Unlock() |
| 38 | eps := c.Endpoints() |
| 39 | // force client to connect to given endpoint by limiting to a single endpoint |
| 40 | c.SetEndpoints(eps[violationCount%len(eps)]) |
| 41 | // give enough time for operation |
| 42 | time.Sleep(1 * time.Second) |
| 43 | // set available endpoints back to all endpoints in to ensure |
| 44 | // the client has access to all the endpoints. |
| 45 | c.SetEndpoints(eps...) |
| 46 | violationCount++ |
| 47 | return nil |
| 48 | } |
| 49 | } |