[VOL-3860] redis client support in voltha-lib-go
redis client support has been added in this patch. There are two
types client `redis` and `redis-sentinel` to connect a redis instance.
redis-sentinel is required to be able to find the master redis
instance from a redis-sentinel process. See redis-sentinel usage
https://redis.io/topics/sentinel and
https://pkg.go.dev/github.com/go-redis/redis/v8#NewFailoverClient
for more information. If there is no need to have any failover
mechanism then the redis client type is the option to choose.
Change-Id: I997ed92115a9d565df632c6dd8184b9bab77b991
diff --git a/vendor/github.com/go-redis/redis/v8/cluster.go b/vendor/github.com/go-redis/redis/v8/cluster.go
new file mode 100644
index 0000000..a6ce5c5
--- /dev/null
+++ b/vendor/github.com/go-redis/redis/v8/cluster.go
@@ -0,0 +1,1697 @@
+package redis
+
+import (
+ "context"
+ "crypto/tls"
+ "fmt"
+ "math"
+ "net"
+ "runtime"
+ "sort"
+ "sync"
+ "sync/atomic"
+ "time"
+
+ "github.com/go-redis/redis/v8/internal"
+ "github.com/go-redis/redis/v8/internal/hashtag"
+ "github.com/go-redis/redis/v8/internal/pool"
+ "github.com/go-redis/redis/v8/internal/proto"
+ "github.com/go-redis/redis/v8/internal/rand"
+)
+
+var errClusterNoNodes = fmt.Errorf("redis: cluster has no nodes")
+
+// ClusterOptions are used to configure a cluster client and should be
+// passed to NewClusterClient.
+type ClusterOptions struct {
+ // A seed list of host:port addresses of cluster nodes.
+ Addrs []string
+
+ // NewClient creates a cluster node client with provided name and options.
+ NewClient func(opt *Options) *Client
+
+ // The maximum number of retries before giving up. Command is retried
+ // on network errors and MOVED/ASK redirects.
+ // Default is 3 retries.
+ MaxRedirects int
+
+ // Enables read-only commands on slave nodes.
+ ReadOnly bool
+ // Allows routing read-only commands to the closest master or slave node.
+ // It automatically enables ReadOnly.
+ RouteByLatency bool
+ // Allows routing read-only commands to the random master or slave node.
+ // It automatically enables ReadOnly.
+ RouteRandomly bool
+
+ // Optional function that returns cluster slots information.
+ // It is useful to manually create cluster of standalone Redis servers
+ // and load-balance read/write operations between master and slaves.
+ // It can use service like ZooKeeper to maintain configuration information
+ // and Cluster.ReloadState to manually trigger state reloading.
+ ClusterSlots func(context.Context) ([]ClusterSlot, error)
+
+ // Following options are copied from Options struct.
+
+ Dialer func(ctx context.Context, network, addr string) (net.Conn, error)
+
+ OnConnect func(ctx context.Context, cn *Conn) error
+
+ Username string
+ Password string
+
+ MaxRetries int
+ MinRetryBackoff time.Duration
+ MaxRetryBackoff time.Duration
+
+ DialTimeout time.Duration
+ ReadTimeout time.Duration
+ WriteTimeout time.Duration
+
+ // PoolSize applies per cluster node and not for the whole cluster.
+ PoolSize int
+ MinIdleConns int
+ MaxConnAge time.Duration
+ PoolTimeout time.Duration
+ IdleTimeout time.Duration
+ IdleCheckFrequency time.Duration
+
+ TLSConfig *tls.Config
+}
+
+func (opt *ClusterOptions) init() {
+ if opt.MaxRedirects == -1 {
+ opt.MaxRedirects = 0
+ } else if opt.MaxRedirects == 0 {
+ opt.MaxRedirects = 3
+ }
+
+ if (opt.RouteByLatency || opt.RouteRandomly) && opt.ClusterSlots == nil {
+ opt.ReadOnly = true
+ }
+
+ if opt.PoolSize == 0 {
+ opt.PoolSize = 5 * runtime.NumCPU()
+ }
+
+ switch opt.ReadTimeout {
+ case -1:
+ opt.ReadTimeout = 0
+ case 0:
+ opt.ReadTimeout = 3 * time.Second
+ }
+ switch opt.WriteTimeout {
+ case -1:
+ opt.WriteTimeout = 0
+ case 0:
+ opt.WriteTimeout = opt.ReadTimeout
+ }
+
+ if opt.MaxRetries == 0 {
+ opt.MaxRetries = -1
+ }
+ switch opt.MinRetryBackoff {
+ case -1:
+ opt.MinRetryBackoff = 0
+ case 0:
+ opt.MinRetryBackoff = 8 * time.Millisecond
+ }
+ switch opt.MaxRetryBackoff {
+ case -1:
+ opt.MaxRetryBackoff = 0
+ case 0:
+ opt.MaxRetryBackoff = 512 * time.Millisecond
+ }
+
+ if opt.NewClient == nil {
+ opt.NewClient = NewClient
+ }
+}
+
+func (opt *ClusterOptions) clientOptions() *Options {
+ const disableIdleCheck = -1
+
+ return &Options{
+ Dialer: opt.Dialer,
+ OnConnect: opt.OnConnect,
+
+ Username: opt.Username,
+ Password: opt.Password,
+
+ MaxRetries: opt.MaxRetries,
+ MinRetryBackoff: opt.MinRetryBackoff,
+ MaxRetryBackoff: opt.MaxRetryBackoff,
+
+ DialTimeout: opt.DialTimeout,
+ ReadTimeout: opt.ReadTimeout,
+ WriteTimeout: opt.WriteTimeout,
+
+ PoolSize: opt.PoolSize,
+ MinIdleConns: opt.MinIdleConns,
+ MaxConnAge: opt.MaxConnAge,
+ PoolTimeout: opt.PoolTimeout,
+ IdleTimeout: opt.IdleTimeout,
+ IdleCheckFrequency: disableIdleCheck,
+
+ readOnly: opt.ReadOnly,
+
+ TLSConfig: opt.TLSConfig,
+ }
+}
+
+//------------------------------------------------------------------------------
+
+type clusterNode struct {
+ Client *Client
+
+ latency uint32 // atomic
+ generation uint32 // atomic
+ failing uint32 // atomic
+}
+
+func newClusterNode(clOpt *ClusterOptions, addr string) *clusterNode {
+ opt := clOpt.clientOptions()
+ opt.Addr = addr
+ node := clusterNode{
+ Client: clOpt.NewClient(opt),
+ }
+
+ node.latency = math.MaxUint32
+ if clOpt.RouteByLatency {
+ go node.updateLatency()
+ }
+
+ return &node
+}
+
+func (n *clusterNode) String() string {
+ return n.Client.String()
+}
+
+func (n *clusterNode) Close() error {
+ return n.Client.Close()
+}
+
+func (n *clusterNode) updateLatency() {
+ const numProbe = 10
+ var dur uint64
+
+ for i := 0; i < numProbe; i++ {
+ time.Sleep(time.Duration(10+rand.Intn(10)) * time.Millisecond)
+
+ start := time.Now()
+ n.Client.Ping(context.TODO())
+ dur += uint64(time.Since(start) / time.Microsecond)
+ }
+
+ latency := float64(dur) / float64(numProbe)
+ atomic.StoreUint32(&n.latency, uint32(latency+0.5))
+}
+
+func (n *clusterNode) Latency() time.Duration {
+ latency := atomic.LoadUint32(&n.latency)
+ return time.Duration(latency) * time.Microsecond
+}
+
+func (n *clusterNode) MarkAsFailing() {
+ atomic.StoreUint32(&n.failing, uint32(time.Now().Unix()))
+}
+
+func (n *clusterNode) Failing() bool {
+ const timeout = 15 // 15 seconds
+
+ failing := atomic.LoadUint32(&n.failing)
+ if failing == 0 {
+ return false
+ }
+ if time.Now().Unix()-int64(failing) < timeout {
+ return true
+ }
+ atomic.StoreUint32(&n.failing, 0)
+ return false
+}
+
+func (n *clusterNode) Generation() uint32 {
+ return atomic.LoadUint32(&n.generation)
+}
+
+func (n *clusterNode) SetGeneration(gen uint32) {
+ for {
+ v := atomic.LoadUint32(&n.generation)
+ if gen < v || atomic.CompareAndSwapUint32(&n.generation, v, gen) {
+ break
+ }
+ }
+}
+
+//------------------------------------------------------------------------------
+
+type clusterNodes struct {
+ opt *ClusterOptions
+
+ mu sync.RWMutex
+ addrs []string
+ nodes map[string]*clusterNode
+ activeAddrs []string
+ closed bool
+
+ _generation uint32 // atomic
+}
+
+func newClusterNodes(opt *ClusterOptions) *clusterNodes {
+ return &clusterNodes{
+ opt: opt,
+
+ addrs: opt.Addrs,
+ nodes: make(map[string]*clusterNode),
+ }
+}
+
+func (c *clusterNodes) Close() error {
+ c.mu.Lock()
+ defer c.mu.Unlock()
+
+ if c.closed {
+ return nil
+ }
+ c.closed = true
+
+ var firstErr error
+ for _, node := range c.nodes {
+ if err := node.Client.Close(); err != nil && firstErr == nil {
+ firstErr = err
+ }
+ }
+
+ c.nodes = nil
+ c.activeAddrs = nil
+
+ return firstErr
+}
+
+func (c *clusterNodes) Addrs() ([]string, error) {
+ var addrs []string
+ c.mu.RLock()
+ closed := c.closed
+ if !closed {
+ if len(c.activeAddrs) > 0 {
+ addrs = c.activeAddrs
+ } else {
+ addrs = c.addrs
+ }
+ }
+ c.mu.RUnlock()
+
+ if closed {
+ return nil, pool.ErrClosed
+ }
+ if len(addrs) == 0 {
+ return nil, errClusterNoNodes
+ }
+ return addrs, nil
+}
+
+func (c *clusterNodes) NextGeneration() uint32 {
+ return atomic.AddUint32(&c._generation, 1)
+}
+
+// GC removes unused nodes.
+func (c *clusterNodes) GC(generation uint32) {
+ //nolint:prealloc
+ var collected []*clusterNode
+
+ c.mu.Lock()
+
+ c.activeAddrs = c.activeAddrs[:0]
+ for addr, node := range c.nodes {
+ if node.Generation() >= generation {
+ c.activeAddrs = append(c.activeAddrs, addr)
+ if c.opt.RouteByLatency {
+ go node.updateLatency()
+ }
+ continue
+ }
+
+ delete(c.nodes, addr)
+ collected = append(collected, node)
+ }
+
+ c.mu.Unlock()
+
+ for _, node := range collected {
+ _ = node.Client.Close()
+ }
+}
+
+func (c *clusterNodes) Get(addr string) (*clusterNode, error) {
+ node, err := c.get(addr)
+ if err != nil {
+ return nil, err
+ }
+ if node != nil {
+ return node, nil
+ }
+
+ c.mu.Lock()
+ defer c.mu.Unlock()
+
+ if c.closed {
+ return nil, pool.ErrClosed
+ }
+
+ node, ok := c.nodes[addr]
+ if ok {
+ return node, nil
+ }
+
+ node = newClusterNode(c.opt, addr)
+
+ c.addrs = appendIfNotExists(c.addrs, addr)
+ c.nodes[addr] = node
+
+ return node, nil
+}
+
+func (c *clusterNodes) get(addr string) (*clusterNode, error) {
+ var node *clusterNode
+ var err error
+ c.mu.RLock()
+ if c.closed {
+ err = pool.ErrClosed
+ } else {
+ node = c.nodes[addr]
+ }
+ c.mu.RUnlock()
+ return node, err
+}
+
+func (c *clusterNodes) All() ([]*clusterNode, error) {
+ c.mu.RLock()
+ defer c.mu.RUnlock()
+
+ if c.closed {
+ return nil, pool.ErrClosed
+ }
+
+ cp := make([]*clusterNode, 0, len(c.nodes))
+ for _, node := range c.nodes {
+ cp = append(cp, node)
+ }
+ return cp, nil
+}
+
+func (c *clusterNodes) Random() (*clusterNode, error) {
+ addrs, err := c.Addrs()
+ if err != nil {
+ return nil, err
+ }
+
+ n := rand.Intn(len(addrs))
+ return c.Get(addrs[n])
+}
+
+//------------------------------------------------------------------------------
+
+type clusterSlot struct {
+ start, end int
+ nodes []*clusterNode
+}
+
+type clusterSlotSlice []*clusterSlot
+
+func (p clusterSlotSlice) Len() int {
+ return len(p)
+}
+
+func (p clusterSlotSlice) Less(i, j int) bool {
+ return p[i].start < p[j].start
+}
+
+func (p clusterSlotSlice) Swap(i, j int) {
+ p[i], p[j] = p[j], p[i]
+}
+
+type clusterState struct {
+ nodes *clusterNodes
+ Masters []*clusterNode
+ Slaves []*clusterNode
+
+ slots []*clusterSlot
+
+ generation uint32
+ createdAt time.Time
+}
+
+func newClusterState(
+ nodes *clusterNodes, slots []ClusterSlot, origin string,
+) (*clusterState, error) {
+ c := clusterState{
+ nodes: nodes,
+
+ slots: make([]*clusterSlot, 0, len(slots)),
+
+ generation: nodes.NextGeneration(),
+ createdAt: time.Now(),
+ }
+
+ originHost, _, _ := net.SplitHostPort(origin)
+ isLoopbackOrigin := isLoopback(originHost)
+
+ for _, slot := range slots {
+ var nodes []*clusterNode
+ for i, slotNode := range slot.Nodes {
+ addr := slotNode.Addr
+ if !isLoopbackOrigin {
+ addr = replaceLoopbackHost(addr, originHost)
+ }
+
+ node, err := c.nodes.Get(addr)
+ if err != nil {
+ return nil, err
+ }
+
+ node.SetGeneration(c.generation)
+ nodes = append(nodes, node)
+
+ if i == 0 {
+ c.Masters = appendUniqueNode(c.Masters, node)
+ } else {
+ c.Slaves = appendUniqueNode(c.Slaves, node)
+ }
+ }
+
+ c.slots = append(c.slots, &clusterSlot{
+ start: slot.Start,
+ end: slot.End,
+ nodes: nodes,
+ })
+ }
+
+ sort.Sort(clusterSlotSlice(c.slots))
+
+ time.AfterFunc(time.Minute, func() {
+ nodes.GC(c.generation)
+ })
+
+ return &c, nil
+}
+
+func replaceLoopbackHost(nodeAddr, originHost string) string {
+ nodeHost, nodePort, err := net.SplitHostPort(nodeAddr)
+ if err != nil {
+ return nodeAddr
+ }
+
+ nodeIP := net.ParseIP(nodeHost)
+ if nodeIP == nil {
+ return nodeAddr
+ }
+
+ if !nodeIP.IsLoopback() {
+ return nodeAddr
+ }
+
+ // Use origin host which is not loopback and node port.
+ return net.JoinHostPort(originHost, nodePort)
+}
+
+func isLoopback(host string) bool {
+ ip := net.ParseIP(host)
+ if ip == nil {
+ return true
+ }
+ return ip.IsLoopback()
+}
+
+func (c *clusterState) slotMasterNode(slot int) (*clusterNode, error) {
+ nodes := c.slotNodes(slot)
+ if len(nodes) > 0 {
+ return nodes[0], nil
+ }
+ return c.nodes.Random()
+}
+
+func (c *clusterState) slotSlaveNode(slot int) (*clusterNode, error) {
+ nodes := c.slotNodes(slot)
+ switch len(nodes) {
+ case 0:
+ return c.nodes.Random()
+ case 1:
+ return nodes[0], nil
+ case 2:
+ if slave := nodes[1]; !slave.Failing() {
+ return slave, nil
+ }
+ return nodes[0], nil
+ default:
+ var slave *clusterNode
+ for i := 0; i < 10; i++ {
+ n := rand.Intn(len(nodes)-1) + 1
+ slave = nodes[n]
+ if !slave.Failing() {
+ return slave, nil
+ }
+ }
+
+ // All slaves are loading - use master.
+ return nodes[0], nil
+ }
+}
+
+func (c *clusterState) slotClosestNode(slot int) (*clusterNode, error) {
+ nodes := c.slotNodes(slot)
+ if len(nodes) == 0 {
+ return c.nodes.Random()
+ }
+
+ var node *clusterNode
+ for _, n := range nodes {
+ if n.Failing() {
+ continue
+ }
+ if node == nil || n.Latency() < node.Latency() {
+ node = n
+ }
+ }
+ if node != nil {
+ return node, nil
+ }
+
+ // If all nodes are failing - return random node
+ return c.nodes.Random()
+}
+
+func (c *clusterState) slotRandomNode(slot int) (*clusterNode, error) {
+ nodes := c.slotNodes(slot)
+ if len(nodes) == 0 {
+ return c.nodes.Random()
+ }
+ n := rand.Intn(len(nodes))
+ return nodes[n], nil
+}
+
+func (c *clusterState) slotNodes(slot int) []*clusterNode {
+ i := sort.Search(len(c.slots), func(i int) bool {
+ return c.slots[i].end >= slot
+ })
+ if i >= len(c.slots) {
+ return nil
+ }
+ x := c.slots[i]
+ if slot >= x.start && slot <= x.end {
+ return x.nodes
+ }
+ return nil
+}
+
+//------------------------------------------------------------------------------
+
+type clusterStateHolder struct {
+ load func(ctx context.Context) (*clusterState, error)
+
+ state atomic.Value
+ reloading uint32 // atomic
+}
+
+func newClusterStateHolder(fn func(ctx context.Context) (*clusterState, error)) *clusterStateHolder {
+ return &clusterStateHolder{
+ load: fn,
+ }
+}
+
+func (c *clusterStateHolder) Reload(ctx context.Context) (*clusterState, error) {
+ state, err := c.load(ctx)
+ if err != nil {
+ return nil, err
+ }
+ c.state.Store(state)
+ return state, nil
+}
+
+func (c *clusterStateHolder) LazyReload(ctx context.Context) {
+ if !atomic.CompareAndSwapUint32(&c.reloading, 0, 1) {
+ return
+ }
+ go func() {
+ defer atomic.StoreUint32(&c.reloading, 0)
+
+ _, err := c.Reload(ctx)
+ if err != nil {
+ return
+ }
+ time.Sleep(200 * time.Millisecond)
+ }()
+}
+
+func (c *clusterStateHolder) Get(ctx context.Context) (*clusterState, error) {
+ v := c.state.Load()
+ if v != nil {
+ state := v.(*clusterState)
+ if time.Since(state.createdAt) > 10*time.Second {
+ c.LazyReload(ctx)
+ }
+ return state, nil
+ }
+ return c.Reload(ctx)
+}
+
+func (c *clusterStateHolder) ReloadOrGet(ctx context.Context) (*clusterState, error) {
+ state, err := c.Reload(ctx)
+ if err == nil {
+ return state, nil
+ }
+ return c.Get(ctx)
+}
+
+//------------------------------------------------------------------------------
+
+type clusterClient struct {
+ opt *ClusterOptions
+ nodes *clusterNodes
+ state *clusterStateHolder //nolint:structcheck
+ cmdsInfoCache *cmdsInfoCache //nolint:structcheck
+}
+
+// ClusterClient is a Redis Cluster client representing a pool of zero
+// or more underlying connections. It's safe for concurrent use by
+// multiple goroutines.
+type ClusterClient struct {
+ *clusterClient
+ cmdable
+ hooks
+ ctx context.Context
+}
+
+// NewClusterClient returns a Redis Cluster client as described in
+// http://redis.io/topics/cluster-spec.
+func NewClusterClient(opt *ClusterOptions) *ClusterClient {
+ opt.init()
+
+ c := &ClusterClient{
+ clusterClient: &clusterClient{
+ opt: opt,
+ nodes: newClusterNodes(opt),
+ },
+ ctx: context.Background(),
+ }
+ c.state = newClusterStateHolder(c.loadState)
+ c.cmdsInfoCache = newCmdsInfoCache(c.cmdsInfo)
+ c.cmdable = c.Process
+
+ if opt.IdleCheckFrequency > 0 {
+ go c.reaper(opt.IdleCheckFrequency)
+ }
+
+ return c
+}
+
+func (c *ClusterClient) Context() context.Context {
+ return c.ctx
+}
+
+func (c *ClusterClient) WithContext(ctx context.Context) *ClusterClient {
+ if ctx == nil {
+ panic("nil context")
+ }
+ clone := *c
+ clone.cmdable = clone.Process
+ clone.hooks.lock()
+ clone.ctx = ctx
+ return &clone
+}
+
+// Options returns read-only Options that were used to create the client.
+func (c *ClusterClient) Options() *ClusterOptions {
+ return c.opt
+}
+
+// ReloadState reloads cluster state. If available it calls ClusterSlots func
+// to get cluster slots information.
+func (c *ClusterClient) ReloadState(ctx context.Context) {
+ c.state.LazyReload(ctx)
+}
+
+// Close closes the cluster client, releasing any open resources.
+//
+// It is rare to Close a ClusterClient, as the ClusterClient is meant
+// to be long-lived and shared between many goroutines.
+func (c *ClusterClient) Close() error {
+ return c.nodes.Close()
+}
+
+// Do creates a Cmd from the args and processes the cmd.
+func (c *ClusterClient) Do(ctx context.Context, args ...interface{}) *Cmd {
+ cmd := NewCmd(ctx, args...)
+ _ = c.Process(ctx, cmd)
+ return cmd
+}
+
+func (c *ClusterClient) Process(ctx context.Context, cmd Cmder) error {
+ return c.hooks.process(ctx, cmd, c.process)
+}
+
+func (c *ClusterClient) process(ctx context.Context, cmd Cmder) error {
+ cmdInfo := c.cmdInfo(cmd.Name())
+ slot := c.cmdSlot(cmd)
+
+ var node *clusterNode
+ var ask bool
+ var lastErr error
+ for attempt := 0; attempt <= c.opt.MaxRedirects; attempt++ {
+ if attempt > 0 {
+ if err := internal.Sleep(ctx, c.retryBackoff(attempt)); err != nil {
+ return err
+ }
+ }
+
+ if node == nil {
+ var err error
+ node, err = c.cmdNode(ctx, cmdInfo, slot)
+ if err != nil {
+ return err
+ }
+ }
+
+ if ask {
+ pipe := node.Client.Pipeline()
+ _ = pipe.Process(ctx, NewCmd(ctx, "asking"))
+ _ = pipe.Process(ctx, cmd)
+ _, lastErr = pipe.Exec(ctx)
+ _ = pipe.Close()
+ ask = false
+ } else {
+ lastErr = node.Client.Process(ctx, cmd)
+ }
+
+ // If there is no error - we are done.
+ if lastErr == nil {
+ return nil
+ }
+ if isReadOnly := isReadOnlyError(lastErr); isReadOnly || lastErr == pool.ErrClosed {
+ if isReadOnly {
+ c.state.LazyReload(ctx)
+ }
+ node = nil
+ continue
+ }
+
+ // If slave is loading - pick another node.
+ if c.opt.ReadOnly && isLoadingError(lastErr) {
+ node.MarkAsFailing()
+ node = nil
+ continue
+ }
+
+ var moved bool
+ var addr string
+ moved, ask, addr = isMovedError(lastErr)
+ if moved || ask {
+ var err error
+ node, err = c.nodes.Get(addr)
+ if err != nil {
+ return err
+ }
+ continue
+ }
+
+ if shouldRetry(lastErr, cmd.readTimeout() == nil) {
+ // First retry the same node.
+ if attempt == 0 {
+ continue
+ }
+
+ // Second try another node.
+ node.MarkAsFailing()
+ node = nil
+ continue
+ }
+
+ return lastErr
+ }
+ return lastErr
+}
+
+// ForEachMaster concurrently calls the fn on each master node in the cluster.
+// It returns the first error if any.
+func (c *ClusterClient) ForEachMaster(
+ ctx context.Context,
+ fn func(ctx context.Context, client *Client) error,
+) error {
+ state, err := c.state.ReloadOrGet(ctx)
+ if err != nil {
+ return err
+ }
+
+ var wg sync.WaitGroup
+ errCh := make(chan error, 1)
+
+ for _, master := range state.Masters {
+ wg.Add(1)
+ go func(node *clusterNode) {
+ defer wg.Done()
+ err := fn(ctx, node.Client)
+ if err != nil {
+ select {
+ case errCh <- err:
+ default:
+ }
+ }
+ }(master)
+ }
+
+ wg.Wait()
+
+ select {
+ case err := <-errCh:
+ return err
+ default:
+ return nil
+ }
+}
+
+// ForEachSlave concurrently calls the fn on each slave node in the cluster.
+// It returns the first error if any.
+func (c *ClusterClient) ForEachSlave(
+ ctx context.Context,
+ fn func(ctx context.Context, client *Client) error,
+) error {
+ state, err := c.state.ReloadOrGet(ctx)
+ if err != nil {
+ return err
+ }
+
+ var wg sync.WaitGroup
+ errCh := make(chan error, 1)
+
+ for _, slave := range state.Slaves {
+ wg.Add(1)
+ go func(node *clusterNode) {
+ defer wg.Done()
+ err := fn(ctx, node.Client)
+ if err != nil {
+ select {
+ case errCh <- err:
+ default:
+ }
+ }
+ }(slave)
+ }
+
+ wg.Wait()
+
+ select {
+ case err := <-errCh:
+ return err
+ default:
+ return nil
+ }
+}
+
+// ForEachShard concurrently calls the fn on each known node in the cluster.
+// It returns the first error if any.
+func (c *ClusterClient) ForEachShard(
+ ctx context.Context,
+ fn func(ctx context.Context, client *Client) error,
+) error {
+ state, err := c.state.ReloadOrGet(ctx)
+ if err != nil {
+ return err
+ }
+
+ var wg sync.WaitGroup
+ errCh := make(chan error, 1)
+
+ worker := func(node *clusterNode) {
+ defer wg.Done()
+ err := fn(ctx, node.Client)
+ if err != nil {
+ select {
+ case errCh <- err:
+ default:
+ }
+ }
+ }
+
+ for _, node := range state.Masters {
+ wg.Add(1)
+ go worker(node)
+ }
+ for _, node := range state.Slaves {
+ wg.Add(1)
+ go worker(node)
+ }
+
+ wg.Wait()
+
+ select {
+ case err := <-errCh:
+ return err
+ default:
+ return nil
+ }
+}
+
+// PoolStats returns accumulated connection pool stats.
+func (c *ClusterClient) PoolStats() *PoolStats {
+ var acc PoolStats
+
+ state, _ := c.state.Get(context.TODO())
+ if state == nil {
+ return &acc
+ }
+
+ for _, node := range state.Masters {
+ s := node.Client.connPool.Stats()
+ acc.Hits += s.Hits
+ acc.Misses += s.Misses
+ acc.Timeouts += s.Timeouts
+
+ acc.TotalConns += s.TotalConns
+ acc.IdleConns += s.IdleConns
+ acc.StaleConns += s.StaleConns
+ }
+
+ for _, node := range state.Slaves {
+ s := node.Client.connPool.Stats()
+ acc.Hits += s.Hits
+ acc.Misses += s.Misses
+ acc.Timeouts += s.Timeouts
+
+ acc.TotalConns += s.TotalConns
+ acc.IdleConns += s.IdleConns
+ acc.StaleConns += s.StaleConns
+ }
+
+ return &acc
+}
+
+func (c *ClusterClient) loadState(ctx context.Context) (*clusterState, error) {
+ if c.opt.ClusterSlots != nil {
+ slots, err := c.opt.ClusterSlots(ctx)
+ if err != nil {
+ return nil, err
+ }
+ return newClusterState(c.nodes, slots, "")
+ }
+
+ addrs, err := c.nodes.Addrs()
+ if err != nil {
+ return nil, err
+ }
+
+ var firstErr error
+
+ for _, idx := range rand.Perm(len(addrs)) {
+ addr := addrs[idx]
+
+ node, err := c.nodes.Get(addr)
+ if err != nil {
+ if firstErr == nil {
+ firstErr = err
+ }
+ continue
+ }
+
+ slots, err := node.Client.ClusterSlots(ctx).Result()
+ if err != nil {
+ if firstErr == nil {
+ firstErr = err
+ }
+ continue
+ }
+
+ return newClusterState(c.nodes, slots, node.Client.opt.Addr)
+ }
+
+ /*
+ * No node is connectable. It's possible that all nodes' IP has changed.
+ * Clear activeAddrs to let client be able to re-connect using the initial
+ * setting of the addresses (e.g. [redis-cluster-0:6379, redis-cluster-1:6379]),
+ * which might have chance to resolve domain name and get updated IP address.
+ */
+ c.nodes.mu.Lock()
+ c.nodes.activeAddrs = nil
+ c.nodes.mu.Unlock()
+
+ return nil, firstErr
+}
+
+// reaper closes idle connections to the cluster.
+func (c *ClusterClient) reaper(idleCheckFrequency time.Duration) {
+ ticker := time.NewTicker(idleCheckFrequency)
+ defer ticker.Stop()
+
+ for range ticker.C {
+ nodes, err := c.nodes.All()
+ if err != nil {
+ break
+ }
+
+ for _, node := range nodes {
+ _, err := node.Client.connPool.(*pool.ConnPool).ReapStaleConns()
+ if err != nil {
+ internal.Logger.Printf(c.Context(), "ReapStaleConns failed: %s", err)
+ }
+ }
+ }
+}
+
+func (c *ClusterClient) Pipeline() Pipeliner {
+ pipe := Pipeline{
+ ctx: c.ctx,
+ exec: c.processPipeline,
+ }
+ pipe.init()
+ return &pipe
+}
+
+func (c *ClusterClient) Pipelined(ctx context.Context, fn func(Pipeliner) error) ([]Cmder, error) {
+ return c.Pipeline().Pipelined(ctx, fn)
+}
+
+func (c *ClusterClient) processPipeline(ctx context.Context, cmds []Cmder) error {
+ return c.hooks.processPipeline(ctx, cmds, c._processPipeline)
+}
+
+func (c *ClusterClient) _processPipeline(ctx context.Context, cmds []Cmder) error {
+ cmdsMap := newCmdsMap()
+ err := c.mapCmdsByNode(ctx, cmdsMap, cmds)
+ if err != nil {
+ setCmdsErr(cmds, err)
+ return err
+ }
+
+ for attempt := 0; attempt <= c.opt.MaxRedirects; attempt++ {
+ if attempt > 0 {
+ if err := internal.Sleep(ctx, c.retryBackoff(attempt)); err != nil {
+ setCmdsErr(cmds, err)
+ return err
+ }
+ }
+
+ failedCmds := newCmdsMap()
+ var wg sync.WaitGroup
+
+ for node, cmds := range cmdsMap.m {
+ wg.Add(1)
+ go func(node *clusterNode, cmds []Cmder) {
+ defer wg.Done()
+
+ err := c._processPipelineNode(ctx, node, cmds, failedCmds)
+ if err == nil {
+ return
+ }
+ if attempt < c.opt.MaxRedirects {
+ if err := c.mapCmdsByNode(ctx, failedCmds, cmds); err != nil {
+ setCmdsErr(cmds, err)
+ }
+ } else {
+ setCmdsErr(cmds, err)
+ }
+ }(node, cmds)
+ }
+
+ wg.Wait()
+ if len(failedCmds.m) == 0 {
+ break
+ }
+ cmdsMap = failedCmds
+ }
+
+ return cmdsFirstErr(cmds)
+}
+
+func (c *ClusterClient) mapCmdsByNode(ctx context.Context, cmdsMap *cmdsMap, cmds []Cmder) error {
+ state, err := c.state.Get(ctx)
+ if err != nil {
+ return err
+ }
+
+ if c.opt.ReadOnly && c.cmdsAreReadOnly(cmds) {
+ for _, cmd := range cmds {
+ slot := c.cmdSlot(cmd)
+ node, err := c.slotReadOnlyNode(state, slot)
+ if err != nil {
+ return err
+ }
+ cmdsMap.Add(node, cmd)
+ }
+ return nil
+ }
+
+ for _, cmd := range cmds {
+ slot := c.cmdSlot(cmd)
+ node, err := state.slotMasterNode(slot)
+ if err != nil {
+ return err
+ }
+ cmdsMap.Add(node, cmd)
+ }
+ return nil
+}
+
+func (c *ClusterClient) cmdsAreReadOnly(cmds []Cmder) bool {
+ for _, cmd := range cmds {
+ cmdInfo := c.cmdInfo(cmd.Name())
+ if cmdInfo == nil || !cmdInfo.ReadOnly {
+ return false
+ }
+ }
+ return true
+}
+
+func (c *ClusterClient) _processPipelineNode(
+ ctx context.Context, node *clusterNode, cmds []Cmder, failedCmds *cmdsMap,
+) error {
+ return node.Client.hooks.processPipeline(ctx, cmds, func(ctx context.Context, cmds []Cmder) error {
+ return node.Client.withConn(ctx, func(ctx context.Context, cn *pool.Conn) error {
+ err := cn.WithWriter(ctx, c.opt.WriteTimeout, func(wr *proto.Writer) error {
+ return writeCmds(wr, cmds)
+ })
+ if err != nil {
+ return err
+ }
+
+ return cn.WithReader(ctx, c.opt.ReadTimeout, func(rd *proto.Reader) error {
+ return c.pipelineReadCmds(ctx, node, rd, cmds, failedCmds)
+ })
+ })
+ })
+}
+
+func (c *ClusterClient) pipelineReadCmds(
+ ctx context.Context,
+ node *clusterNode,
+ rd *proto.Reader,
+ cmds []Cmder,
+ failedCmds *cmdsMap,
+) error {
+ for _, cmd := range cmds {
+ err := cmd.readReply(rd)
+ cmd.SetErr(err)
+
+ if err == nil {
+ continue
+ }
+
+ if c.checkMovedErr(ctx, cmd, err, failedCmds) {
+ continue
+ }
+
+ if c.opt.ReadOnly && isLoadingError(err) {
+ node.MarkAsFailing()
+ return err
+ }
+ if isRedisError(err) {
+ continue
+ }
+ return err
+ }
+ return nil
+}
+
+func (c *ClusterClient) checkMovedErr(
+ ctx context.Context, cmd Cmder, err error, failedCmds *cmdsMap,
+) bool {
+ moved, ask, addr := isMovedError(err)
+ if !moved && !ask {
+ return false
+ }
+
+ node, err := c.nodes.Get(addr)
+ if err != nil {
+ return false
+ }
+
+ if moved {
+ c.state.LazyReload(ctx)
+ failedCmds.Add(node, cmd)
+ return true
+ }
+
+ if ask {
+ failedCmds.Add(node, NewCmd(ctx, "asking"), cmd)
+ return true
+ }
+
+ panic("not reached")
+}
+
+// TxPipeline acts like Pipeline, but wraps queued commands with MULTI/EXEC.
+func (c *ClusterClient) TxPipeline() Pipeliner {
+ pipe := Pipeline{
+ ctx: c.ctx,
+ exec: c.processTxPipeline,
+ }
+ pipe.init()
+ return &pipe
+}
+
+func (c *ClusterClient) TxPipelined(ctx context.Context, fn func(Pipeliner) error) ([]Cmder, error) {
+ return c.TxPipeline().Pipelined(ctx, fn)
+}
+
+func (c *ClusterClient) processTxPipeline(ctx context.Context, cmds []Cmder) error {
+ return c.hooks.processPipeline(ctx, cmds, c._processTxPipeline)
+}
+
+func (c *ClusterClient) _processTxPipeline(ctx context.Context, cmds []Cmder) error {
+ state, err := c.state.Get(ctx)
+ if err != nil {
+ setCmdsErr(cmds, err)
+ return err
+ }
+
+ cmdsMap := c.mapCmdsBySlot(cmds)
+ for slot, cmds := range cmdsMap {
+ node, err := state.slotMasterNode(slot)
+ if err != nil {
+ setCmdsErr(cmds, err)
+ continue
+ }
+
+ cmdsMap := map[*clusterNode][]Cmder{node: cmds}
+ for attempt := 0; attempt <= c.opt.MaxRedirects; attempt++ {
+ if attempt > 0 {
+ if err := internal.Sleep(ctx, c.retryBackoff(attempt)); err != nil {
+ setCmdsErr(cmds, err)
+ return err
+ }
+ }
+
+ failedCmds := newCmdsMap()
+ var wg sync.WaitGroup
+
+ for node, cmds := range cmdsMap {
+ wg.Add(1)
+ go func(node *clusterNode, cmds []Cmder) {
+ defer wg.Done()
+
+ err := c._processTxPipelineNode(ctx, node, cmds, failedCmds)
+ if err == nil {
+ return
+ }
+ if attempt < c.opt.MaxRedirects {
+ if err := c.mapCmdsByNode(ctx, failedCmds, cmds); err != nil {
+ setCmdsErr(cmds, err)
+ }
+ } else {
+ setCmdsErr(cmds, err)
+ }
+ }(node, cmds)
+ }
+
+ wg.Wait()
+ if len(failedCmds.m) == 0 {
+ break
+ }
+ cmdsMap = failedCmds.m
+ }
+ }
+
+ return cmdsFirstErr(cmds)
+}
+
+func (c *ClusterClient) mapCmdsBySlot(cmds []Cmder) map[int][]Cmder {
+ cmdsMap := make(map[int][]Cmder)
+ for _, cmd := range cmds {
+ slot := c.cmdSlot(cmd)
+ cmdsMap[slot] = append(cmdsMap[slot], cmd)
+ }
+ return cmdsMap
+}
+
+func (c *ClusterClient) _processTxPipelineNode(
+ ctx context.Context, node *clusterNode, cmds []Cmder, failedCmds *cmdsMap,
+) error {
+ return node.Client.hooks.processTxPipeline(ctx, cmds, func(ctx context.Context, cmds []Cmder) error {
+ return node.Client.withConn(ctx, func(ctx context.Context, cn *pool.Conn) error {
+ err := cn.WithWriter(ctx, c.opt.WriteTimeout, func(wr *proto.Writer) error {
+ return writeCmds(wr, cmds)
+ })
+ if err != nil {
+ return err
+ }
+
+ return cn.WithReader(ctx, c.opt.ReadTimeout, func(rd *proto.Reader) error {
+ statusCmd := cmds[0].(*StatusCmd)
+ // Trim multi and exec.
+ cmds = cmds[1 : len(cmds)-1]
+
+ err := c.txPipelineReadQueued(ctx, rd, statusCmd, cmds, failedCmds)
+ if err != nil {
+ moved, ask, addr := isMovedError(err)
+ if moved || ask {
+ return c.cmdsMoved(ctx, cmds, moved, ask, addr, failedCmds)
+ }
+ return err
+ }
+
+ return pipelineReadCmds(rd, cmds)
+ })
+ })
+ })
+}
+
+func (c *ClusterClient) txPipelineReadQueued(
+ ctx context.Context,
+ rd *proto.Reader,
+ statusCmd *StatusCmd,
+ cmds []Cmder,
+ failedCmds *cmdsMap,
+) error {
+ // Parse queued replies.
+ if err := statusCmd.readReply(rd); err != nil {
+ return err
+ }
+
+ for _, cmd := range cmds {
+ err := statusCmd.readReply(rd)
+ if err == nil || c.checkMovedErr(ctx, cmd, err, failedCmds) || isRedisError(err) {
+ continue
+ }
+ return err
+ }
+
+ // Parse number of replies.
+ line, err := rd.ReadLine()
+ if err != nil {
+ if err == Nil {
+ err = TxFailedErr
+ }
+ return err
+ }
+
+ switch line[0] {
+ case proto.ErrorReply:
+ return proto.ParseErrorReply(line)
+ case proto.ArrayReply:
+ // ok
+ default:
+ return fmt.Errorf("redis: expected '*', but got line %q", line)
+ }
+
+ return nil
+}
+
+func (c *ClusterClient) cmdsMoved(
+ ctx context.Context, cmds []Cmder,
+ moved, ask bool,
+ addr string,
+ failedCmds *cmdsMap,
+) error {
+ node, err := c.nodes.Get(addr)
+ if err != nil {
+ return err
+ }
+
+ if moved {
+ c.state.LazyReload(ctx)
+ for _, cmd := range cmds {
+ failedCmds.Add(node, cmd)
+ }
+ return nil
+ }
+
+ if ask {
+ for _, cmd := range cmds {
+ failedCmds.Add(node, NewCmd(ctx, "asking"), cmd)
+ }
+ return nil
+ }
+
+ return nil
+}
+
+func (c *ClusterClient) Watch(ctx context.Context, fn func(*Tx) error, keys ...string) error {
+ if len(keys) == 0 {
+ return fmt.Errorf("redis: Watch requires at least one key")
+ }
+
+ slot := hashtag.Slot(keys[0])
+ for _, key := range keys[1:] {
+ if hashtag.Slot(key) != slot {
+ err := fmt.Errorf("redis: Watch requires all keys to be in the same slot")
+ return err
+ }
+ }
+
+ node, err := c.slotMasterNode(ctx, slot)
+ if err != nil {
+ return err
+ }
+
+ for attempt := 0; attempt <= c.opt.MaxRedirects; attempt++ {
+ if attempt > 0 {
+ if err := internal.Sleep(ctx, c.retryBackoff(attempt)); err != nil {
+ return err
+ }
+ }
+
+ err = node.Client.Watch(ctx, fn, keys...)
+ if err == nil {
+ break
+ }
+
+ moved, ask, addr := isMovedError(err)
+ if moved || ask {
+ node, err = c.nodes.Get(addr)
+ if err != nil {
+ return err
+ }
+ continue
+ }
+
+ if isReadOnly := isReadOnlyError(err); isReadOnly || err == pool.ErrClosed {
+ if isReadOnly {
+ c.state.LazyReload(ctx)
+ }
+ node, err = c.slotMasterNode(ctx, slot)
+ if err != nil {
+ return err
+ }
+ continue
+ }
+
+ if shouldRetry(err, true) {
+ continue
+ }
+
+ return err
+ }
+
+ return err
+}
+
+func (c *ClusterClient) pubSub() *PubSub {
+ var node *clusterNode
+ pubsub := &PubSub{
+ opt: c.opt.clientOptions(),
+
+ newConn: func(ctx context.Context, channels []string) (*pool.Conn, error) {
+ if node != nil {
+ panic("node != nil")
+ }
+
+ var err error
+ if len(channels) > 0 {
+ slot := hashtag.Slot(channels[0])
+ node, err = c.slotMasterNode(ctx, slot)
+ } else {
+ node, err = c.nodes.Random()
+ }
+ if err != nil {
+ return nil, err
+ }
+
+ cn, err := node.Client.newConn(context.TODO())
+ if err != nil {
+ node = nil
+
+ return nil, err
+ }
+
+ return cn, nil
+ },
+ closeConn: func(cn *pool.Conn) error {
+ err := node.Client.connPool.CloseConn(cn)
+ node = nil
+ return err
+ },
+ }
+ pubsub.init()
+
+ return pubsub
+}
+
+// Subscribe subscribes the client to the specified channels.
+// Channels can be omitted to create empty subscription.
+func (c *ClusterClient) Subscribe(ctx context.Context, channels ...string) *PubSub {
+ pubsub := c.pubSub()
+ if len(channels) > 0 {
+ _ = pubsub.Subscribe(ctx, channels...)
+ }
+ return pubsub
+}
+
+// PSubscribe subscribes the client to the given patterns.
+// Patterns can be omitted to create empty subscription.
+func (c *ClusterClient) PSubscribe(ctx context.Context, channels ...string) *PubSub {
+ pubsub := c.pubSub()
+ if len(channels) > 0 {
+ _ = pubsub.PSubscribe(ctx, channels...)
+ }
+ return pubsub
+}
+
+func (c *ClusterClient) retryBackoff(attempt int) time.Duration {
+ return internal.RetryBackoff(attempt, c.opt.MinRetryBackoff, c.opt.MaxRetryBackoff)
+}
+
+func (c *ClusterClient) cmdsInfo(ctx context.Context) (map[string]*CommandInfo, error) {
+ // Try 3 random nodes.
+ const nodeLimit = 3
+
+ addrs, err := c.nodes.Addrs()
+ if err != nil {
+ return nil, err
+ }
+
+ var firstErr error
+
+ perm := rand.Perm(len(addrs))
+ if len(perm) > nodeLimit {
+ perm = perm[:nodeLimit]
+ }
+
+ for _, idx := range perm {
+ addr := addrs[idx]
+
+ node, err := c.nodes.Get(addr)
+ if err != nil {
+ if firstErr == nil {
+ firstErr = err
+ }
+ continue
+ }
+
+ info, err := node.Client.Command(ctx).Result()
+ if err == nil {
+ return info, nil
+ }
+ if firstErr == nil {
+ firstErr = err
+ }
+ }
+
+ if firstErr == nil {
+ panic("not reached")
+ }
+ return nil, firstErr
+}
+
+func (c *ClusterClient) cmdInfo(name string) *CommandInfo {
+ cmdsInfo, err := c.cmdsInfoCache.Get(c.ctx)
+ if err != nil {
+ return nil
+ }
+
+ info := cmdsInfo[name]
+ if info == nil {
+ internal.Logger.Printf(c.Context(), "info for cmd=%s not found", name)
+ }
+ return info
+}
+
+func (c *ClusterClient) cmdSlot(cmd Cmder) int {
+ args := cmd.Args()
+ if args[0] == "cluster" && args[1] == "getkeysinslot" {
+ return args[2].(int)
+ }
+
+ cmdInfo := c.cmdInfo(cmd.Name())
+ return cmdSlot(cmd, cmdFirstKeyPos(cmd, cmdInfo))
+}
+
+func cmdSlot(cmd Cmder, pos int) int {
+ if pos == 0 {
+ return hashtag.RandomSlot()
+ }
+ firstKey := cmd.stringArg(pos)
+ return hashtag.Slot(firstKey)
+}
+
+func (c *ClusterClient) cmdNode(
+ ctx context.Context,
+ cmdInfo *CommandInfo,
+ slot int,
+) (*clusterNode, error) {
+ state, err := c.state.Get(ctx)
+ if err != nil {
+ return nil, err
+ }
+
+ if (c.opt.RouteByLatency || c.opt.RouteRandomly) && cmdInfo != nil && cmdInfo.ReadOnly {
+ return c.slotReadOnlyNode(state, slot)
+ }
+ return state.slotMasterNode(slot)
+}
+
+func (c *clusterClient) slotReadOnlyNode(state *clusterState, slot int) (*clusterNode, error) {
+ if c.opt.RouteByLatency {
+ return state.slotClosestNode(slot)
+ }
+ if c.opt.RouteRandomly {
+ return state.slotRandomNode(slot)
+ }
+ return state.slotSlaveNode(slot)
+}
+
+func (c *ClusterClient) slotMasterNode(ctx context.Context, slot int) (*clusterNode, error) {
+ state, err := c.state.Get(ctx)
+ if err != nil {
+ return nil, err
+ }
+ return state.slotMasterNode(slot)
+}
+
+func appendUniqueNode(nodes []*clusterNode, node *clusterNode) []*clusterNode {
+ for _, n := range nodes {
+ if n == node {
+ return nodes
+ }
+ }
+ return append(nodes, node)
+}
+
+func appendIfNotExists(ss []string, es ...string) []string {
+loop:
+ for _, e := range es {
+ for _, s := range ss {
+ if s == e {
+ continue loop
+ }
+ }
+ ss = append(ss, e)
+ }
+ return ss
+}
+
+//------------------------------------------------------------------------------
+
+type cmdsMap struct {
+ mu sync.Mutex
+ m map[*clusterNode][]Cmder
+}
+
+func newCmdsMap() *cmdsMap {
+ return &cmdsMap{
+ m: make(map[*clusterNode][]Cmder),
+ }
+}
+
+func (m *cmdsMap) Add(node *clusterNode, cmds ...Cmder) {
+ m.mu.Lock()
+ m.m[node] = append(m.m[node], cmds...)
+ m.mu.Unlock()
+}