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Scott Baker2c1c4822019-10-16 11:02:41 -07001/*
2 * Copyright 2018-present Open Networking Foundation
3
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7
8 * http://www.apache.org/licenses/LICENSE-2.0
9
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
sbarbari1e3e29c2019-11-05 10:06:50 -050017package db
Scott Baker2c1c4822019-10-16 11:02:41 -070018
19import (
Girish Kumarca522102019-11-08 11:26:35 +000020 "context"
Scott Baker2c1c4822019-10-16 11:02:41 -070021 "errors"
22 "fmt"
Girish Kumarca522102019-11-08 11:26:35 +000023 "time"
serkant.uluderyab38671c2019-11-01 09:35:38 -070024
25 "github.com/opencord/voltha-lib-go/v3/pkg/db/kvstore"
26 "github.com/opencord/voltha-lib-go/v3/pkg/log"
27 "google.golang.org/grpc/codes"
28 "google.golang.org/grpc/status"
Girish Kumarca522102019-11-08 11:26:35 +000029)
30
31const (
32 // Default Minimal Interval for posting alive state of backend kvstore on Liveness Channel
33 DefaultLivenessChannelInterval = time.Second * 30
Scott Baker2c1c4822019-10-16 11:02:41 -070034)
35
Scott Baker2c1c4822019-10-16 11:02:41 -070036// Backend structure holds details for accessing the kv store
37type Backend struct {
Girish Kumarca522102019-11-08 11:26:35 +000038 Client kvstore.Client
39 StoreType string
Neha Sharma130ac6d2020-04-08 08:46:32 +000040 Timeout time.Duration
Neha Sharmadd9af392020-04-28 09:03:57 +000041 Address string
Girish Kumarca522102019-11-08 11:26:35 +000042 PathPrefix string
43 alive bool // Is this backend connection alive?
44 liveness chan bool // channel to post alive state
45 LivenessChannelInterval time.Duration // regularly push alive state beyond this interval
46 lastLivenessTime time.Time // Instant of last alive state push
Scott Baker2c1c4822019-10-16 11:02:41 -070047}
48
49// NewBackend creates a new instance of a Backend structure
Neha Sharmadd9af392020-04-28 09:03:57 +000050func NewBackend(storeType string, address string, timeout time.Duration, pathPrefix string) *Backend {
Scott Baker2c1c4822019-10-16 11:02:41 -070051 var err error
52
53 b := &Backend{
Girish Kumarca522102019-11-08 11:26:35 +000054 StoreType: storeType,
Neha Sharmadd9af392020-04-28 09:03:57 +000055 Address: address,
Girish Kumarca522102019-11-08 11:26:35 +000056 Timeout: timeout,
57 LivenessChannelInterval: DefaultLivenessChannelInterval,
58 PathPrefix: pathPrefix,
59 alive: false, // connection considered down at start
Scott Baker2c1c4822019-10-16 11:02:41 -070060 }
61
Scott Baker2c1c4822019-10-16 11:02:41 -070062 if b.Client, err = b.newClient(address, timeout); err != nil {
khenaidoob332f9b2020-01-16 16:25:26 -050063 logger.Errorw("failed-to-create-kv-client",
Scott Baker2c1c4822019-10-16 11:02:41 -070064 log.Fields{
Neha Sharmadd9af392020-04-28 09:03:57 +000065 "type": storeType, "address": address,
Scott Baker2c1c4822019-10-16 11:02:41 -070066 "timeout": timeout, "prefix": pathPrefix,
67 "error": err.Error(),
68 })
69 }
70
71 return b
72}
73
Neha Sharma130ac6d2020-04-08 08:46:32 +000074func (b *Backend) newClient(address string, timeout time.Duration) (kvstore.Client, error) {
Scott Baker2c1c4822019-10-16 11:02:41 -070075 switch b.StoreType {
76 case "consul":
77 return kvstore.NewConsulClient(address, timeout)
78 case "etcd":
Rohan Agrawalee87e642020-04-14 10:22:18 +000079 return kvstore.NewEtcdClient(address, timeout, log.WarnLevel)
Scott Baker2c1c4822019-10-16 11:02:41 -070080 }
81 return nil, errors.New("unsupported-kv-store")
82}
83
84func (b *Backend) makePath(key string) string {
85 path := fmt.Sprintf("%s/%s", b.PathPrefix, key)
86 return path
87}
88
Girish Kumarca522102019-11-08 11:26:35 +000089func (b *Backend) updateLiveness(alive bool) {
90 // Periodically push stream of liveness data to the channel,
91 // so that in a live state, the core does not timeout and
92 // send a forced liveness message. Push alive state if the
93 // last push to channel was beyond livenessChannelInterval
94 if b.liveness != nil {
95
96 if b.alive != alive {
khenaidoob332f9b2020-01-16 16:25:26 -050097 logger.Debug("update-liveness-channel-reason-change")
Girish Kumarca522102019-11-08 11:26:35 +000098 b.liveness <- alive
99 b.lastLivenessTime = time.Now()
David K. Bainbridge7c75cac2020-02-19 08:53:46 -0800100 } else if time.Since(b.lastLivenessTime) > b.LivenessChannelInterval {
khenaidoob332f9b2020-01-16 16:25:26 -0500101 logger.Debug("update-liveness-channel-reason-interval")
Girish Kumarca522102019-11-08 11:26:35 +0000102 b.liveness <- alive
103 b.lastLivenessTime = time.Now()
104 }
105 }
106
107 // Emit log message only for alive state change
108 if b.alive != alive {
khenaidoob332f9b2020-01-16 16:25:26 -0500109 logger.Debugw("change-kvstore-alive-status", log.Fields{"alive": alive})
Girish Kumarca522102019-11-08 11:26:35 +0000110 b.alive = alive
111 }
112}
113
114// Perform a dummy Key Lookup on kvstore to test Connection Liveness and
115// post on Liveness channel
npujar5bf737f2020-01-16 19:35:25 +0530116func (b *Backend) PerformLivenessCheck(ctx context.Context) bool {
117 alive := b.Client.IsConnectionUp(ctx)
khenaidoob332f9b2020-01-16 16:25:26 -0500118 logger.Debugw("kvstore-liveness-check-result", log.Fields{"alive": alive})
Girish Kumarca522102019-11-08 11:26:35 +0000119
120 b.updateLiveness(alive)
121 return alive
122}
123
124// Enable the liveness monitor channel. This channel will report
125// a "true" or "false" on every kvstore operation which indicates whether
126// or not the connection is still Live. This channel is then picked up
127// by the service (i.e. rw_core / ro_core) to update readiness status
128// and/or take other actions.
129func (b *Backend) EnableLivenessChannel() chan bool {
khenaidoob332f9b2020-01-16 16:25:26 -0500130 logger.Debug("enable-kvstore-liveness-channel")
Girish Kumarca522102019-11-08 11:26:35 +0000131
132 if b.liveness == nil {
khenaidoob332f9b2020-01-16 16:25:26 -0500133 logger.Debug("create-kvstore-liveness-channel")
Girish Kumarca522102019-11-08 11:26:35 +0000134
135 // Channel size of 10 to avoid any possibility of blocking in Load conditions
136 b.liveness = make(chan bool, 10)
137
138 // Post initial alive state
139 b.liveness <- b.alive
140 b.lastLivenessTime = time.Now()
141 }
142
143 return b.liveness
144}
145
146// Extract Alive status of Kvstore based on type of error
147func (b *Backend) isErrorIndicatingAliveKvstore(err error) bool {
148 // Alive unless observed an error indicating so
149 alive := true
150
151 if err != nil {
152
153 // timeout indicates kvstore not reachable/alive
154 if err == context.DeadlineExceeded {
155 alive = false
156 }
157
158 // Need to analyze client-specific errors based on backend type
159 if b.StoreType == "etcd" {
160
161 // For etcd backend, consider not-alive only for errors indicating
162 // timedout request or unavailable/corrupted cluster. For all remaining
163 // error codes listed in https://godoc.org/google.golang.org/grpc/codes#Code,
164 // we would not infer a not-alive backend because such a error may also
165 // occur due to bad client requests or sequence of operations
166 switch status.Code(err) {
167 case codes.DeadlineExceeded:
168 fallthrough
169 case codes.Unavailable:
170 fallthrough
171 case codes.DataLoss:
172 alive = false
173 }
174
175 //} else {
176 // TODO: Implement for consul backend; would it be needed ever?
177 }
178 }
179
180 return alive
181}
182
Scott Baker2c1c4822019-10-16 11:02:41 -0700183// List retrieves one or more items that match the specified key
npujar5bf737f2020-01-16 19:35:25 +0530184func (b *Backend) List(ctx context.Context, key string) (map[string]*kvstore.KVPair, error) {
Scott Baker2c1c4822019-10-16 11:02:41 -0700185 formattedPath := b.makePath(key)
khenaidoob332f9b2020-01-16 16:25:26 -0500186 logger.Debugw("listing-key", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700187
npujar5bf737f2020-01-16 19:35:25 +0530188 pair, err := b.Client.List(ctx, formattedPath)
Girish Kumarca522102019-11-08 11:26:35 +0000189
190 b.updateLiveness(b.isErrorIndicatingAliveKvstore(err))
191
192 return pair, err
Scott Baker2c1c4822019-10-16 11:02:41 -0700193}
194
195// Get retrieves an item that matches the specified key
npujar5bf737f2020-01-16 19:35:25 +0530196func (b *Backend) Get(ctx context.Context, key string) (*kvstore.KVPair, error) {
Scott Baker2c1c4822019-10-16 11:02:41 -0700197 formattedPath := b.makePath(key)
khenaidoob332f9b2020-01-16 16:25:26 -0500198 logger.Debugw("getting-key", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700199
npujar5bf737f2020-01-16 19:35:25 +0530200 pair, err := b.Client.Get(ctx, formattedPath)
Girish Kumarca522102019-11-08 11:26:35 +0000201
202 b.updateLiveness(b.isErrorIndicatingAliveKvstore(err))
203
204 return pair, err
Scott Baker2c1c4822019-10-16 11:02:41 -0700205}
206
207// Put stores an item value under the specifed key
npujar5bf737f2020-01-16 19:35:25 +0530208func (b *Backend) Put(ctx context.Context, key string, value interface{}) error {
Scott Baker2c1c4822019-10-16 11:02:41 -0700209 formattedPath := b.makePath(key)
Matteo Scandolo4fca23a2020-04-07 07:55:08 -0700210 logger.Debugw("putting-key", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700211
npujar5bf737f2020-01-16 19:35:25 +0530212 err := b.Client.Put(ctx, formattedPath, value)
Girish Kumarca522102019-11-08 11:26:35 +0000213
214 b.updateLiveness(b.isErrorIndicatingAliveKvstore(err))
215
216 return err
Scott Baker2c1c4822019-10-16 11:02:41 -0700217}
218
219// Delete removes an item under the specified key
npujar5bf737f2020-01-16 19:35:25 +0530220func (b *Backend) Delete(ctx context.Context, key string) error {
Scott Baker2c1c4822019-10-16 11:02:41 -0700221 formattedPath := b.makePath(key)
khenaidoob332f9b2020-01-16 16:25:26 -0500222 logger.Debugw("deleting-key", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700223
npujar5bf737f2020-01-16 19:35:25 +0530224 err := b.Client.Delete(ctx, formattedPath)
Girish Kumarca522102019-11-08 11:26:35 +0000225
226 b.updateLiveness(b.isErrorIndicatingAliveKvstore(err))
227
228 return err
Scott Baker2c1c4822019-10-16 11:02:41 -0700229}
230
231// CreateWatch starts watching events for the specified key
divyadesai8bf96862020-02-07 12:24:26 +0000232func (b *Backend) CreateWatch(ctx context.Context, key string, withPrefix bool) chan *kvstore.Event {
Scott Baker2c1c4822019-10-16 11:02:41 -0700233 formattedPath := b.makePath(key)
khenaidoob332f9b2020-01-16 16:25:26 -0500234 logger.Debugw("creating-key-watch", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700235
divyadesai8bf96862020-02-07 12:24:26 +0000236 return b.Client.Watch(ctx, formattedPath, withPrefix)
Scott Baker2c1c4822019-10-16 11:02:41 -0700237}
238
239// DeleteWatch stops watching events for the specified key
240func (b *Backend) DeleteWatch(key string, ch chan *kvstore.Event) {
Scott Baker2c1c4822019-10-16 11:02:41 -0700241 formattedPath := b.makePath(key)
khenaidoob332f9b2020-01-16 16:25:26 -0500242 logger.Debugw("deleting-key-watch", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700243
244 b.Client.CloseWatch(formattedPath, ch)
245}