git-hulk commented on code in PR #126: URL: https://github.com/apache/kvrocks-controller/pull/126#discussion_r1405562159
########## storage/persistence/zookeeper/zookeeper.go: ########## @@ -0,0 +1,260 @@ +/* + * 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 zookeeper + +import ( + "context" + "errors" + "strings" + "sync" + "time" + + "github.com/apache/kvrocks-controller/logger" + "github.com/apache/kvrocks-controller/storage/persistence" + "github.com/go-zookeeper/zk" + "go.uber.org/atomic" +) + +const ( + sessionTTL = 6 + defaultDailTimeout = 5 * time.Second +) + +const defaultElectPath = "/kvrocks/controller/leader" + +type Config struct { + Addrs []string `yaml:"addrs"` + Scheme string `yaml:"scheme"` + Auth string `yaml:"auth"` + ElectPath string `yaml:"elect_path"` +} + +type Zookeeper struct { + conn *zk.Conn + acl []zk.ACL // We will set this ACL for the node we have created + leaderMu sync.RWMutex + leaderID string + myID string + electPath string + isReady atomic.Bool + quitCh chan struct{} + leaderChangeCh chan bool +} + +func New(id string, cfg *Config) (*Zookeeper, error) { + if len(id) == 0 { + return nil, errors.New("id must NOT be a empty string") + } + conn, _, err := zk.Connect(cfg.Addrs, defaultDailTimeout) + if err != nil { + return nil, err + } + electPath := defaultElectPath + if cfg.ElectPath != "" { + electPath = cfg.ElectPath + } + acl := zk.WorldACL(zk.PermAll) + if cfg.Scheme != "" && cfg.Auth != "" { + err := conn.AddAuth(cfg.Scheme, []byte(cfg.Auth)) + if err == nil { + acl = []zk.ACL{{Perms: zk.PermAll, Scheme: cfg.Scheme, ID: cfg.Auth}} + } else { + logger.Get().Warn("Zookeeper addAuth fail: " + err.Error()) + } + } + e := &Zookeeper{ + myID: id, + acl: acl, + electPath: electPath, + conn: conn, + quitCh: make(chan struct{}), + leaderChangeCh: make(chan bool), + } + e.isReady.Store(false) + go e.observeLeaderEvent(context.Background()) + return e, nil +} + +func (e *Zookeeper) ID() string { + return e.myID +} + +func (e *Zookeeper) Leader() string { + e.leaderMu.RLock() + defer e.leaderMu.RUnlock() + return e.leaderID +} + +func (e *Zookeeper) LeaderChange() <-chan bool { + return e.leaderChangeCh +} + +func (e *Zookeeper) IsReady(ctx context.Context) bool { + for { + select { + case <-e.quitCh: + return false + case <-time.After(100 * time.Millisecond): + if e.isReady.Load() { + return true + } + case <-ctx.Done(): + return e.isReady.Load() + } + } +} + +func (e *Zookeeper) Get(ctx context.Context, key string) ([]byte, error) { + data, _, err := e.conn.Get(key) + if err != nil { + if errors.Is(err, zk.ErrNoNode) { + return nil, nil // Key does not exist + } + return nil, err + } + + return data, nil +} + +func (e *Zookeeper) Exists(ctx context.Context, key string) (bool, error) { + exists, _, err := e.conn.Exists(key) + if err != nil { + return false, err + } + return exists, nil +} + +// If the key exists, it will be set; if not, it will be created. +func (e *Zookeeper) Set(ctx context.Context, key string, value []byte) error { + exist, _ := e.Exists(ctx, key) + if exist { + _, err := e.conn.Set(key, value, -1) + return err + } + + return e.Create(ctx, key, value, 0) +} + +func (e *Zookeeper) Create(ctx context.Context, key string, value []byte, flags int32) error { + lastSlashIndex := strings.LastIndex(key, "/") + if lastSlashIndex > 0 { + substring := key[:lastSlashIndex] + // If the parent node does not exist, create the parent node recursively + exist, _ := e.Exists(ctx, substring) + if !exist { + err := e.Create(ctx, substring, []byte{}, 0) + if err != nil { + return err + } + } + } + _, err := e.conn.Create(key, value, flags, e.acl) + return err +} + +func (e *Zookeeper) Delete(ctx context.Context, key string) error { + err := e.conn.Delete(key, -1) + if errors.Is(err, zk.ErrNoNode) { + return nil // Key does not exist + } + return err +} + +func (e *Zookeeper) List(ctx context.Context, prefix string) ([]persistence.Entry, error) { + children, _, err := e.conn.Children(prefix) + if errors.Is(err, zk.ErrNoNode) { + return []persistence.Entry{}, nil + } else if err != nil { + return nil, err + } + + entries := make([]persistence.Entry, 0) + for _, child := range children { + key := prefix + "/" + child + data, _, err := e.conn.Get(key) + if err != nil { + return nil, err + } + + entry := persistence.Entry{ + Key: child, + Value: data, + } + entries = append(entries, entry) + } + + return entries, nil +} + +func (e *Zookeeper) SetleaderID(newLeaderID string) { + if newLeaderID != "" && newLeaderID != e.leaderID { + e.leaderMu.Lock() + e.leaderID = newLeaderID + e.leaderMu.Unlock() + e.leaderChangeCh <- true + } +} + +func (e *Zookeeper) observeLeaderEvent(ctx context.Context) { +reset: + select { + case <-e.quitCh: + return + default: + } + err := e.Create(ctx, e.electPath, []byte(e.myID), zk.FlagEphemeral) + if err != nil && !errors.Is(err, zk.ErrNodeExists) { + goto reset + } + data, _, ch, err := e.conn.GetW(e.electPath) + if err != nil { + goto reset Review Comment: Same as above ########## storage/persistence/zookeeper/zookeeper.go: ########## @@ -0,0 +1,260 @@ +/* + * 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 zookeeper + +import ( + "context" + "errors" + "strings" + "sync" + "time" + + "github.com/apache/kvrocks-controller/logger" + "github.com/apache/kvrocks-controller/storage/persistence" + "github.com/go-zookeeper/zk" + "go.uber.org/atomic" +) + +const ( + sessionTTL = 6 + defaultDailTimeout = 5 * time.Second +) + +const defaultElectPath = "/kvrocks/controller/leader" + +type Config struct { + Addrs []string `yaml:"addrs"` + Scheme string `yaml:"scheme"` + Auth string `yaml:"auth"` + ElectPath string `yaml:"elect_path"` +} + +type Zookeeper struct { + conn *zk.Conn + acl []zk.ACL // We will set this ACL for the node we have created + leaderMu sync.RWMutex + leaderID string + myID string + electPath string + isReady atomic.Bool + quitCh chan struct{} + leaderChangeCh chan bool +} + +func New(id string, cfg *Config) (*Zookeeper, error) { + if len(id) == 0 { + return nil, errors.New("id must NOT be a empty string") + } + conn, _, err := zk.Connect(cfg.Addrs, defaultDailTimeout) + if err != nil { + return nil, err + } + electPath := defaultElectPath + if cfg.ElectPath != "" { + electPath = cfg.ElectPath + } + acl := zk.WorldACL(zk.PermAll) + if cfg.Scheme != "" && cfg.Auth != "" { + err := conn.AddAuth(cfg.Scheme, []byte(cfg.Auth)) + if err == nil { + acl = []zk.ACL{{Perms: zk.PermAll, Scheme: cfg.Scheme, ID: cfg.Auth}} + } else { + logger.Get().Warn("Zookeeper addAuth fail: " + err.Error()) + } + } + e := &Zookeeper{ + myID: id, + acl: acl, + electPath: electPath, + conn: conn, + quitCh: make(chan struct{}), + leaderChangeCh: make(chan bool), + } + e.isReady.Store(false) + go e.observeLeaderEvent(context.Background()) + return e, nil +} + +func (e *Zookeeper) ID() string { + return e.myID +} + +func (e *Zookeeper) Leader() string { + e.leaderMu.RLock() + defer e.leaderMu.RUnlock() + return e.leaderID +} + +func (e *Zookeeper) LeaderChange() <-chan bool { + return e.leaderChangeCh +} + +func (e *Zookeeper) IsReady(ctx context.Context) bool { + for { + select { + case <-e.quitCh: + return false + case <-time.After(100 * time.Millisecond): + if e.isReady.Load() { + return true + } + case <-ctx.Done(): + return e.isReady.Load() + } + } +} + +func (e *Zookeeper) Get(ctx context.Context, key string) ([]byte, error) { + data, _, err := e.conn.Get(key) + if err != nil { + if errors.Is(err, zk.ErrNoNode) { + return nil, nil // Key does not exist + } + return nil, err + } + + return data, nil +} + +func (e *Zookeeper) Exists(ctx context.Context, key string) (bool, error) { + exists, _, err := e.conn.Exists(key) + if err != nil { + return false, err + } + return exists, nil +} + +// If the key exists, it will be set; if not, it will be created. +func (e *Zookeeper) Set(ctx context.Context, key string, value []byte) error { + exist, _ := e.Exists(ctx, key) + if exist { + _, err := e.conn.Set(key, value, -1) + return err + } + + return e.Create(ctx, key, value, 0) +} + +func (e *Zookeeper) Create(ctx context.Context, key string, value []byte, flags int32) error { + lastSlashIndex := strings.LastIndex(key, "/") + if lastSlashIndex > 0 { + substring := key[:lastSlashIndex] + // If the parent node does not exist, create the parent node recursively + exist, _ := e.Exists(ctx, substring) + if !exist { + err := e.Create(ctx, substring, []byte{}, 0) + if err != nil { + return err + } + } + } + _, err := e.conn.Create(key, value, flags, e.acl) + return err +} + +func (e *Zookeeper) Delete(ctx context.Context, key string) error { + err := e.conn.Delete(key, -1) + if errors.Is(err, zk.ErrNoNode) { + return nil // Key does not exist + } + return err +} + +func (e *Zookeeper) List(ctx context.Context, prefix string) ([]persistence.Entry, error) { + children, _, err := e.conn.Children(prefix) + if errors.Is(err, zk.ErrNoNode) { + return []persistence.Entry{}, nil + } else if err != nil { + return nil, err + } + + entries := make([]persistence.Entry, 0) + for _, child := range children { + key := prefix + "/" + child + data, _, err := e.conn.Get(key) + if err != nil { + return nil, err + } + + entry := persistence.Entry{ + Key: child, + Value: data, + } + entries = append(entries, entry) + } + + return entries, nil +} + +func (e *Zookeeper) SetleaderID(newLeaderID string) { + if newLeaderID != "" && newLeaderID != e.leaderID { + e.leaderMu.Lock() + e.leaderID = newLeaderID + e.leaderMu.Unlock() + e.leaderChangeCh <- true + } +} + +func (e *Zookeeper) observeLeaderEvent(ctx context.Context) { +reset: + select { + case <-e.quitCh: + return + default: + } + err := e.Create(ctx, e.electPath, []byte(e.myID), zk.FlagEphemeral) + if err != nil && !errors.Is(err, zk.ErrNodeExists) { + goto reset + } + data, _, ch, err := e.conn.GetW(e.electPath) + if err != nil { + goto reset + } + e.isReady.Store(true) + e.SetleaderID(string(data)) + + for { + select { + case resp := <-ch: + if resp.Type == zk.EventNodeDeleted { + err := e.Create(ctx, e.electPath, []byte(e.myID), zk.FlagEphemeral) + if err != nil && !errors.Is(err, zk.ErrNodeExists) { + goto reset + } + } + data, _, ch, err = e.conn.GetW(e.electPath) + if err != nil { + goto reset + } + e.SetleaderID(string(data)) + case <-e.quitCh: + logger.Get().Info(e.myID + "Exit the leader election loop") + return + } + + } + +} + +func (e *Zookeeper) Close() error { + close(e.quitCh) Review Comment: Need to use `sync.Group` to wait for the routine(`observeLeaderEvent`) before closing the connection. ########## storage/persistence/zookeeper/zookeeper.go: ########## @@ -0,0 +1,260 @@ +/* + * 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 zookeeper + +import ( + "context" + "errors" + "strings" + "sync" + "time" + + "github.com/apache/kvrocks-controller/logger" + "github.com/apache/kvrocks-controller/storage/persistence" + "github.com/go-zookeeper/zk" + "go.uber.org/atomic" +) + +const ( + sessionTTL = 6 + defaultDailTimeout = 5 * time.Second +) + +const defaultElectPath = "/kvrocks/controller/leader" + +type Config struct { + Addrs []string `yaml:"addrs"` + Scheme string `yaml:"scheme"` + Auth string `yaml:"auth"` + ElectPath string `yaml:"elect_path"` +} + +type Zookeeper struct { + conn *zk.Conn + acl []zk.ACL // We will set this ACL for the node we have created + leaderMu sync.RWMutex + leaderID string + myID string + electPath string + isReady atomic.Bool + quitCh chan struct{} + leaderChangeCh chan bool +} + +func New(id string, cfg *Config) (*Zookeeper, error) { + if len(id) == 0 { + return nil, errors.New("id must NOT be a empty string") + } + conn, _, err := zk.Connect(cfg.Addrs, defaultDailTimeout) + if err != nil { + return nil, err + } + electPath := defaultElectPath + if cfg.ElectPath != "" { + electPath = cfg.ElectPath + } + acl := zk.WorldACL(zk.PermAll) + if cfg.Scheme != "" && cfg.Auth != "" { + err := conn.AddAuth(cfg.Scheme, []byte(cfg.Auth)) + if err == nil { + acl = []zk.ACL{{Perms: zk.PermAll, Scheme: cfg.Scheme, ID: cfg.Auth}} + } else { + logger.Get().Warn("Zookeeper addAuth fail: " + err.Error()) + } + } + e := &Zookeeper{ + myID: id, + acl: acl, + electPath: electPath, + conn: conn, + quitCh: make(chan struct{}), + leaderChangeCh: make(chan bool), + } + e.isReady.Store(false) + go e.observeLeaderEvent(context.Background()) + return e, nil +} + +func (e *Zookeeper) ID() string { + return e.myID +} + +func (e *Zookeeper) Leader() string { + e.leaderMu.RLock() + defer e.leaderMu.RUnlock() + return e.leaderID +} + +func (e *Zookeeper) LeaderChange() <-chan bool { + return e.leaderChangeCh +} + +func (e *Zookeeper) IsReady(ctx context.Context) bool { + for { + select { + case <-e.quitCh: + return false + case <-time.After(100 * time.Millisecond): + if e.isReady.Load() { + return true + } + case <-ctx.Done(): + return e.isReady.Load() + } + } +} + +func (e *Zookeeper) Get(ctx context.Context, key string) ([]byte, error) { + data, _, err := e.conn.Get(key) + if err != nil { + if errors.Is(err, zk.ErrNoNode) { + return nil, nil // Key does not exist + } + return nil, err + } + + return data, nil +} + +func (e *Zookeeper) Exists(ctx context.Context, key string) (bool, error) { + exists, _, err := e.conn.Exists(key) + if err != nil { + return false, err + } + return exists, nil +} + +// If the key exists, it will be set; if not, it will be created. +func (e *Zookeeper) Set(ctx context.Context, key string, value []byte) error { + exist, _ := e.Exists(ctx, key) + if exist { + _, err := e.conn.Set(key, value, -1) + return err + } + + return e.Create(ctx, key, value, 0) +} + +func (e *Zookeeper) Create(ctx context.Context, key string, value []byte, flags int32) error { + lastSlashIndex := strings.LastIndex(key, "/") + if lastSlashIndex > 0 { + substring := key[:lastSlashIndex] + // If the parent node does not exist, create the parent node recursively + exist, _ := e.Exists(ctx, substring) + if !exist { + err := e.Create(ctx, substring, []byte{}, 0) + if err != nil { + return err + } + } + } + _, err := e.conn.Create(key, value, flags, e.acl) + return err +} + +func (e *Zookeeper) Delete(ctx context.Context, key string) error { + err := e.conn.Delete(key, -1) + if errors.Is(err, zk.ErrNoNode) { + return nil // Key does not exist + } + return err +} + +func (e *Zookeeper) List(ctx context.Context, prefix string) ([]persistence.Entry, error) { + children, _, err := e.conn.Children(prefix) + if errors.Is(err, zk.ErrNoNode) { + return []persistence.Entry{}, nil + } else if err != nil { + return nil, err + } + + entries := make([]persistence.Entry, 0) + for _, child := range children { + key := prefix + "/" + child + data, _, err := e.conn.Get(key) + if err != nil { + return nil, err + } + + entry := persistence.Entry{ + Key: child, + Value: data, + } + entries = append(entries, entry) + } + + return entries, nil +} + +func (e *Zookeeper) SetleaderID(newLeaderID string) { + if newLeaderID != "" && newLeaderID != e.leaderID { + e.leaderMu.Lock() + e.leaderID = newLeaderID + e.leaderMu.Unlock() + e.leaderChangeCh <- true + } +} + +func (e *Zookeeper) observeLeaderEvent(ctx context.Context) { +reset: + select { + case <-e.quitCh: + return + default: + } + err := e.Create(ctx, e.electPath, []byte(e.myID), zk.FlagEphemeral) + if err != nil && !errors.Is(err, zk.ErrNodeExists) { + goto reset + } Review Comment: Guess we should sleep a while to avoid overrunning if something wrong with the zookeeper. -- This is an automated message from the Apache Git Service. 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