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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"
David K. Bainbridge5edd7fb2020-07-29 19:30:48 -070023 "sync"
Girish Kumarca522102019-11-08 11:26:35 +000024 "time"
serkant.uluderyab38671c2019-11-01 09:35:38 -070025
26 "github.com/opencord/voltha-lib-go/v3/pkg/db/kvstore"
27 "github.com/opencord/voltha-lib-go/v3/pkg/log"
28 "google.golang.org/grpc/codes"
29 "google.golang.org/grpc/status"
Girish Kumarca522102019-11-08 11:26:35 +000030)
31
32const (
33 // Default Minimal Interval for posting alive state of backend kvstore on Liveness Channel
34 DefaultLivenessChannelInterval = time.Second * 30
Scott Baker2c1c4822019-10-16 11:02:41 -070035)
36
Scott Baker2c1c4822019-10-16 11:02:41 -070037// Backend structure holds details for accessing the kv store
38type Backend struct {
Girish Kumarca522102019-11-08 11:26:35 +000039 Client kvstore.Client
40 StoreType string
Neha Sharma130ac6d2020-04-08 08:46:32 +000041 Timeout time.Duration
Neha Sharmadd9af392020-04-28 09:03:57 +000042 Address string
Girish Kumarca522102019-11-08 11:26:35 +000043 PathPrefix string
David K. Bainbridge5edd7fb2020-07-29 19:30:48 -070044 alive bool // Is this backend connection alive?
45 livenessMutex sync.Mutex
Girish Kumarca522102019-11-08 11:26:35 +000046 liveness chan bool // channel to post alive state
47 LivenessChannelInterval time.Duration // regularly push alive state beyond this interval
48 lastLivenessTime time.Time // Instant of last alive state push
Scott Baker2c1c4822019-10-16 11:02:41 -070049}
50
51// NewBackend creates a new instance of a Backend structure
Neha Sharma94f16a92020-06-26 04:17:55 +000052func NewBackend(ctx context.Context, storeType string, address string, timeout time.Duration, pathPrefix string) *Backend {
Scott Baker2c1c4822019-10-16 11:02:41 -070053 var err error
54
55 b := &Backend{
Girish Kumarca522102019-11-08 11:26:35 +000056 StoreType: storeType,
Neha Sharmadd9af392020-04-28 09:03:57 +000057 Address: address,
Girish Kumarca522102019-11-08 11:26:35 +000058 Timeout: timeout,
59 LivenessChannelInterval: DefaultLivenessChannelInterval,
60 PathPrefix: pathPrefix,
61 alive: false, // connection considered down at start
Scott Baker2c1c4822019-10-16 11:02:41 -070062 }
63
Neha Sharma94f16a92020-06-26 04:17:55 +000064 if b.Client, err = b.newClient(ctx, address, timeout); err != nil {
65 logger.Errorw(ctx, "failed-to-create-kv-client",
Scott Baker2c1c4822019-10-16 11:02:41 -070066 log.Fields{
Neha Sharmadd9af392020-04-28 09:03:57 +000067 "type": storeType, "address": address,
Scott Baker2c1c4822019-10-16 11:02:41 -070068 "timeout": timeout, "prefix": pathPrefix,
69 "error": err.Error(),
70 })
71 }
72
73 return b
74}
75
Neha Sharma94f16a92020-06-26 04:17:55 +000076func (b *Backend) newClient(ctx context.Context, address string, timeout time.Duration) (kvstore.Client, error) {
Scott Baker2c1c4822019-10-16 11:02:41 -070077 switch b.StoreType {
78 case "consul":
Neha Sharma94f16a92020-06-26 04:17:55 +000079 return kvstore.NewConsulClient(ctx, address, timeout)
Scott Baker2c1c4822019-10-16 11:02:41 -070080 case "etcd":
Neha Sharma94f16a92020-06-26 04:17:55 +000081 return kvstore.NewEtcdClient(ctx, address, timeout, log.WarnLevel)
Scott Baker2c1c4822019-10-16 11:02:41 -070082 }
83 return nil, errors.New("unsupported-kv-store")
84}
85
Neha Sharma94f16a92020-06-26 04:17:55 +000086func (b *Backend) makePath(ctx context.Context, key string) string {
Scott Baker2c1c4822019-10-16 11:02:41 -070087 path := fmt.Sprintf("%s/%s", b.PathPrefix, key)
88 return path
89}
90
Neha Sharma94f16a92020-06-26 04:17:55 +000091func (b *Backend) updateLiveness(ctx context.Context, alive bool) {
Girish Kumarca522102019-11-08 11:26:35 +000092 // Periodically push stream of liveness data to the channel,
93 // so that in a live state, the core does not timeout and
94 // send a forced liveness message. Push alive state if the
95 // last push to channel was beyond livenessChannelInterval
David K. Bainbridge5edd7fb2020-07-29 19:30:48 -070096 b.livenessMutex.Lock()
97 defer b.livenessMutex.Unlock()
Girish Kumarca522102019-11-08 11:26:35 +000098 if b.liveness != nil {
Girish Kumarca522102019-11-08 11:26:35 +000099 if b.alive != alive {
Neha Sharma94f16a92020-06-26 04:17:55 +0000100 logger.Debug(ctx, "update-liveness-channel-reason-change")
Girish Kumarca522102019-11-08 11:26:35 +0000101 b.liveness <- alive
102 b.lastLivenessTime = time.Now()
David K. Bainbridge7c75cac2020-02-19 08:53:46 -0800103 } else if time.Since(b.lastLivenessTime) > b.LivenessChannelInterval {
Neha Sharma94f16a92020-06-26 04:17:55 +0000104 logger.Debug(ctx, "update-liveness-channel-reason-interval")
Girish Kumarca522102019-11-08 11:26:35 +0000105 b.liveness <- alive
106 b.lastLivenessTime = time.Now()
107 }
108 }
109
110 // Emit log message only for alive state change
111 if b.alive != alive {
Neha Sharma94f16a92020-06-26 04:17:55 +0000112 logger.Debugw(ctx, "change-kvstore-alive-status", log.Fields{"alive": alive})
Girish Kumarca522102019-11-08 11:26:35 +0000113 b.alive = alive
114 }
115}
116
117// Perform a dummy Key Lookup on kvstore to test Connection Liveness and
118// post on Liveness channel
npujar5bf737f2020-01-16 19:35:25 +0530119func (b *Backend) PerformLivenessCheck(ctx context.Context) bool {
120 alive := b.Client.IsConnectionUp(ctx)
Neha Sharma94f16a92020-06-26 04:17:55 +0000121 logger.Debugw(ctx, "kvstore-liveness-check-result", log.Fields{"alive": alive})
Girish Kumarca522102019-11-08 11:26:35 +0000122
Neha Sharma94f16a92020-06-26 04:17:55 +0000123 b.updateLiveness(ctx, alive)
Girish Kumarca522102019-11-08 11:26:35 +0000124 return alive
125}
126
127// Enable the liveness monitor channel. This channel will report
128// a "true" or "false" on every kvstore operation which indicates whether
129// or not the connection is still Live. This channel is then picked up
130// by the service (i.e. rw_core / ro_core) to update readiness status
131// and/or take other actions.
Neha Sharma94f16a92020-06-26 04:17:55 +0000132func (b *Backend) EnableLivenessChannel(ctx context.Context) chan bool {
133 logger.Debug(ctx, "enable-kvstore-liveness-channel")
David K. Bainbridge5edd7fb2020-07-29 19:30:48 -0700134 b.livenessMutex.Lock()
135 defer b.livenessMutex.Unlock()
Girish Kumarca522102019-11-08 11:26:35 +0000136 if b.liveness == nil {
Girish Kumarca522102019-11-08 11:26:35 +0000137 b.liveness = make(chan bool, 10)
Girish Kumarca522102019-11-08 11:26:35 +0000138 b.liveness <- b.alive
139 b.lastLivenessTime = time.Now()
140 }
141
142 return b.liveness
143}
144
145// Extract Alive status of Kvstore based on type of error
Neha Sharma94f16a92020-06-26 04:17:55 +0000146func (b *Backend) isErrorIndicatingAliveKvstore(ctx context.Context, err error) bool {
Girish Kumarca522102019-11-08 11:26:35 +0000147 // Alive unless observed an error indicating so
148 alive := true
149
150 if err != nil {
151
152 // timeout indicates kvstore not reachable/alive
153 if err == context.DeadlineExceeded {
154 alive = false
155 }
156
157 // Need to analyze client-specific errors based on backend type
158 if b.StoreType == "etcd" {
159
160 // For etcd backend, consider not-alive only for errors indicating
161 // timedout request or unavailable/corrupted cluster. For all remaining
162 // error codes listed in https://godoc.org/google.golang.org/grpc/codes#Code,
163 // we would not infer a not-alive backend because such a error may also
164 // occur due to bad client requests or sequence of operations
165 switch status.Code(err) {
166 case codes.DeadlineExceeded:
167 fallthrough
168 case codes.Unavailable:
169 fallthrough
170 case codes.DataLoss:
171 alive = false
172 }
173
174 //} else {
175 // TODO: Implement for consul backend; would it be needed ever?
176 }
177 }
178
179 return alive
180}
181
Scott Baker2c1c4822019-10-16 11:02:41 -0700182// List retrieves one or more items that match the specified key
npujar5bf737f2020-01-16 19:35:25 +0530183func (b *Backend) List(ctx context.Context, key string) (map[string]*kvstore.KVPair, error) {
Rohan Agrawalfb1cb352020-08-03 04:59:32 +0000184 span, ctx := log.CreateChildSpan(ctx, "etcd-list")
185 defer span.Finish()
186
Neha Sharma94f16a92020-06-26 04:17:55 +0000187 formattedPath := b.makePath(ctx, key)
188 logger.Debugw(ctx, "listing-key", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700189
npujar5bf737f2020-01-16 19:35:25 +0530190 pair, err := b.Client.List(ctx, formattedPath)
Girish Kumarca522102019-11-08 11:26:35 +0000191
Neha Sharma94f16a92020-06-26 04:17:55 +0000192 b.updateLiveness(ctx, b.isErrorIndicatingAliveKvstore(ctx, err))
Girish Kumarca522102019-11-08 11:26:35 +0000193
194 return pair, err
Scott Baker2c1c4822019-10-16 11:02:41 -0700195}
196
197// Get retrieves an item that matches the specified key
npujar5bf737f2020-01-16 19:35:25 +0530198func (b *Backend) Get(ctx context.Context, key string) (*kvstore.KVPair, error) {
Rohan Agrawalfb1cb352020-08-03 04:59:32 +0000199 span, ctx := log.CreateChildSpan(ctx, "etcd-get")
200 defer span.Finish()
201
Neha Sharma94f16a92020-06-26 04:17:55 +0000202 formattedPath := b.makePath(ctx, key)
203 logger.Debugw(ctx, "getting-key", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700204
npujar5bf737f2020-01-16 19:35:25 +0530205 pair, err := b.Client.Get(ctx, formattedPath)
Girish Kumarca522102019-11-08 11:26:35 +0000206
Neha Sharma94f16a92020-06-26 04:17:55 +0000207 b.updateLiveness(ctx, b.isErrorIndicatingAliveKvstore(ctx, err))
Girish Kumarca522102019-11-08 11:26:35 +0000208
209 return pair, err
Scott Baker2c1c4822019-10-16 11:02:41 -0700210}
211
212// Put stores an item value under the specifed key
npujar5bf737f2020-01-16 19:35:25 +0530213func (b *Backend) Put(ctx context.Context, key string, value interface{}) error {
Rohan Agrawalfb1cb352020-08-03 04:59:32 +0000214 span, ctx := log.CreateChildSpan(ctx, "etcd-put")
215 defer span.Finish()
216
Neha Sharma94f16a92020-06-26 04:17:55 +0000217 formattedPath := b.makePath(ctx, key)
218 logger.Debugw(ctx, "putting-key", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700219
npujar5bf737f2020-01-16 19:35:25 +0530220 err := b.Client.Put(ctx, formattedPath, value)
Girish Kumarca522102019-11-08 11:26:35 +0000221
Neha Sharma94f16a92020-06-26 04:17:55 +0000222 b.updateLiveness(ctx, b.isErrorIndicatingAliveKvstore(ctx, err))
Girish Kumarca522102019-11-08 11:26:35 +0000223
224 return err
Scott Baker2c1c4822019-10-16 11:02:41 -0700225}
226
227// Delete removes an item under the specified key
npujar5bf737f2020-01-16 19:35:25 +0530228func (b *Backend) Delete(ctx context.Context, key string) error {
Rohan Agrawalfb1cb352020-08-03 04:59:32 +0000229 span, ctx := log.CreateChildSpan(ctx, "etcd-delete")
230 defer span.Finish()
231
Neha Sharma94f16a92020-06-26 04:17:55 +0000232 formattedPath := b.makePath(ctx, key)
233 logger.Debugw(ctx, "deleting-key", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700234
npujar5bf737f2020-01-16 19:35:25 +0530235 err := b.Client.Delete(ctx, formattedPath)
Girish Kumarca522102019-11-08 11:26:35 +0000236
Neha Sharma94f16a92020-06-26 04:17:55 +0000237 b.updateLiveness(ctx, b.isErrorIndicatingAliveKvstore(ctx, err))
Girish Kumarca522102019-11-08 11:26:35 +0000238
239 return err
Scott Baker2c1c4822019-10-16 11:02:41 -0700240}
241
242// CreateWatch starts watching events for the specified key
divyadesai8bf96862020-02-07 12:24:26 +0000243func (b *Backend) CreateWatch(ctx context.Context, key string, withPrefix bool) chan *kvstore.Event {
Rohan Agrawalfb1cb352020-08-03 04:59:32 +0000244 span, ctx := log.CreateChildSpan(ctx, "etcd-create-watch")
245 defer span.Finish()
246
Neha Sharma94f16a92020-06-26 04:17:55 +0000247 formattedPath := b.makePath(ctx, key)
248 logger.Debugw(ctx, "creating-key-watch", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700249
divyadesai8bf96862020-02-07 12:24:26 +0000250 return b.Client.Watch(ctx, formattedPath, withPrefix)
Scott Baker2c1c4822019-10-16 11:02:41 -0700251}
252
253// DeleteWatch stops watching events for the specified key
Neha Sharma94f16a92020-06-26 04:17:55 +0000254func (b *Backend) DeleteWatch(ctx context.Context, key string, ch chan *kvstore.Event) {
Rohan Agrawalfb1cb352020-08-03 04:59:32 +0000255 span, ctx := log.CreateChildSpan(ctx, "etcd-delete-watch")
256 defer span.Finish()
257
Neha Sharma94f16a92020-06-26 04:17:55 +0000258 formattedPath := b.makePath(ctx, key)
259 logger.Debugw(ctx, "deleting-key-watch", log.Fields{"key": key, "path": formattedPath})
Scott Baker2c1c4822019-10-16 11:02:41 -0700260
Neha Sharma94f16a92020-06-26 04:17:55 +0000261 b.Client.CloseWatch(ctx, formattedPath, ch)
Scott Baker2c1c4822019-10-16 11:02:41 -0700262}