Add latency based routing to Redis Cluster client.

This commit is contained in:
Joris Minjat 2016-05-06 11:12:31 -07:00 committed by Vladimir Mihailenco
parent 3972f28066
commit 487feebef1
11 changed files with 760 additions and 509 deletions

View File

@ -11,6 +11,12 @@ import (
"gopkg.in/redis.v4/internal/pool"
)
type clusterNode struct {
Addr string
Latency int
Client *Client
}
// ClusterClient is a Redis Cluster client representing a pool of zero
// or more underlying connections. It's safe for concurrent use by
// multiple goroutines.
@ -19,14 +25,14 @@ type ClusterClient struct {
opt *ClusterOptions
slotsMx sync.RWMutex // protects slots and addrs
addrs []string
slots [][]string
mu sync.RWMutex
addrs []string
nodes map[string]*clusterNode
slots [][]*clusterNode
closed bool
clientsMx sync.RWMutex // protects clients and closed
clients map[string]*Client
_closed int32 // atomic
cmdsInfo map[string]*CommandInfo
cmdsInfoOnce *sync.Once
// Reports where slots reloading is in progress.
reloading uint32
@ -35,44 +41,63 @@ type ClusterClient struct {
// NewClusterClient returns a Redis Cluster client as described in
// http://redis.io/topics/cluster-spec.
func NewClusterClient(opt *ClusterOptions) *ClusterClient {
if opt.RouteByLatency {
opt.ReadOnly = true
}
client := &ClusterClient{
opt: opt,
addrs: opt.Addrs,
slots: make([][]string, hashtag.SlotNumber),
clients: make(map[string]*Client),
opt: opt,
nodes: make(map[string]*clusterNode),
cmdsInfoOnce: new(sync.Once),
}
client.commandable.process = client.process
for _, addr := range opt.Addrs {
_ = client.nodeByAddr(addr)
}
client.reloadSlots()
return client
}
// getClients returns a snapshot of clients for cluster nodes
// this ClusterClient has been working with recently.
// Note that snapshot can contain closed clients.
func (c *ClusterClient) getClients() map[string]*Client {
c.clientsMx.RLock()
clients := make(map[string]*Client, len(c.clients))
for addr, client := range c.clients {
clients[addr] = client
func (c *ClusterClient) cmdInfo(name string) *CommandInfo {
c.cmdsInfoOnce.Do(func() {
for _, node := range c.nodes {
cmdsInfo, err := node.Client.Command().Result()
if err == nil {
c.cmdsInfo = cmdsInfo
return
}
}
c.cmdsInfoOnce = &sync.Once{}
})
return c.cmdsInfo[name]
}
func (c *ClusterClient) getNodes() map[string]*clusterNode {
c.mu.RLock()
var nodes map[string]*clusterNode
if !c.closed {
nodes = make(map[string]*clusterNode, len(c.nodes))
for addr, node := range c.nodes {
nodes[addr] = node
}
}
c.clientsMx.RUnlock()
return clients
c.mu.RUnlock()
return nodes
}
func (c *ClusterClient) Watch(fn func(*Tx) error, keys ...string) error {
addr := c.slotMasterAddr(hashtag.Slot(keys[0]))
client, err := c.getClient(addr)
if err != nil {
return err
}
return client.Watch(fn, keys...)
node := c.slotMasterNode(hashtag.Slot(keys[0]))
return node.Client.Watch(fn, keys...)
}
// PoolStats returns accumulated connection pool stats.
func (c *ClusterClient) PoolStats() *PoolStats {
acc := PoolStats{}
for _, client := range c.getClients() {
s := client.connPool.Stats()
for _, node := range c.getNodes() {
s := node.Client.connPool.Stats()
acc.Requests += s.Requests
acc.Hits += s.Hits
acc.Timeouts += s.Timeouts
@ -82,113 +107,163 @@ func (c *ClusterClient) PoolStats() *PoolStats {
return &acc
}
func (c *ClusterClient) closed() bool {
return atomic.LoadInt32(&c._closed) == 1
}
// 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 {
if !atomic.CompareAndSwapInt32(&c._closed, 0, 1) {
return pool.ErrClosed
c.mu.Lock()
if !c.closed {
c.closeClients()
c.addrs = nil
c.nodes = nil
c.slots = nil
c.cmdsInfo = nil
}
c.clientsMx.Lock()
c.resetClients()
c.clientsMx.Unlock()
c.setSlots(nil)
c.closed = true
c.mu.Unlock()
return nil
}
// getClient returns a Client for a given address.
func (c *ClusterClient) getClient(addr string) (*Client, error) {
if c.closed() {
return nil, pool.ErrClosed
}
if addr == "" {
return c.randomClient()
}
c.clientsMx.RLock()
client, ok := c.clients[addr]
c.clientsMx.RUnlock()
func (c *ClusterClient) nodeByAddr(addr string) *clusterNode {
c.mu.RLock()
node, ok := c.nodes[addr]
c.mu.RUnlock()
if ok {
return client, nil
return node
}
c.clientsMx.Lock()
client, ok = c.clients[addr]
if !ok {
opt := c.opt.clientOptions()
opt.Addr = addr
client = NewClient(opt)
c.clients[addr] = client
c.mu.Lock()
if !c.closed {
node, ok = c.nodes[addr]
if !ok {
node = c.newNode(addr)
c.nodes[addr] = node
c.addrs = append(c.addrs, node.Addr)
}
}
c.clientsMx.Unlock()
c.mu.Unlock()
return client, nil
return node
}
func (c *ClusterClient) slotAddrs(slot int) []string {
c.slotsMx.RLock()
addrs := c.slots[slot]
c.slotsMx.RUnlock()
return addrs
}
func (c *ClusterClient) slotMasterAddr(slot int) string {
addrs := c.slotAddrs(slot)
if len(addrs) > 0 {
return addrs[0]
func (c *ClusterClient) newNode(addr string) *clusterNode {
opt := c.opt.clientOptions()
opt.Addr = addr
return &clusterNode{
Addr: addr,
Client: NewClient(opt),
}
return ""
}
// randomClient returns a Client for the first live node.
func (c *ClusterClient) randomClient() (client *Client, err error) {
func (c *ClusterClient) slotNodes(slot int) []*clusterNode {
c.mu.RLock()
nodes := c.slots[slot]
c.mu.RUnlock()
return nodes
}
// randomNode returns random live node.
func (c *ClusterClient) randomNode() *clusterNode {
var node *clusterNode
for i := 0; i < 10; i++ {
n := rand.Intn(len(c.addrs))
client, err = c.getClient(c.addrs[n])
if err != nil {
continue
c.mu.RLock()
addrs := c.addrs
c.mu.RUnlock()
if len(addrs) == 0 {
return nil
}
err = client.ClusterInfo().Err()
if err == nil {
return client, nil
n := rand.Intn(len(addrs))
node = c.nodeByAddr(addrs[n])
if node.Client.ClusterInfo().Err() == nil {
return node
}
}
return nil, err
return node
}
func (c *ClusterClient) slotMasterNode(slot int) *clusterNode {
nodes := c.slotNodes(slot)
if len(nodes) == 0 {
return c.randomNode()
}
return nodes[0]
}
func (c *ClusterClient) slotSlaveNode(slot int) *clusterNode {
nodes := c.slotNodes(slot)
switch len(nodes) {
case 0:
return c.randomNode()
case 1:
return nodes[0]
case 2:
return nodes[1]
default:
n := rand.Intn(len(nodes)-1) + 1
return nodes[n]
}
}
func (c *ClusterClient) slotClosestNode(slot int) *clusterNode {
nodes := c.slotNodes(slot)
var node *clusterNode
for _, n := range nodes {
if node == nil || n.Latency < node.Latency {
node = n
}
}
return node
}
func (c *ClusterClient) cmdSlotAndNode(cmd Cmder) (int, *clusterNode) {
cmdInfo := c.cmdInfo(cmd.arg(0))
if cmdInfo == nil {
return 0, c.randomNode()
}
if cmdInfo.FirstKeyPos == -1 {
return 0, c.randomNode()
}
firstKey := cmd.arg(int(cmdInfo.FirstKeyPos))
slot := hashtag.Slot(firstKey)
if cmdInfo.ReadOnly && c.opt.ReadOnly {
if c.opt.RouteByLatency {
return slot, c.slotClosestNode(slot)
}
return slot, c.slotSlaveNode(slot)
}
return slot, c.slotMasterNode(slot)
}
func (c *ClusterClient) process(cmd Cmder) {
var ask bool
slot := hashtag.Slot(cmd.clusterKey())
addr := c.slotMasterAddr(slot)
client, err := c.getClient(addr)
if err != nil {
cmd.setErr(err)
return
}
slot, node := c.cmdSlotAndNode(cmd)
for attempt := 0; attempt <= c.opt.getMaxRedirects(); attempt++ {
if attempt > 0 {
cmd.reset()
}
if node == nil {
cmd.setErr(pool.ErrClosed)
return
}
if ask {
pipe := client.Pipeline()
pipe := node.Client.Pipeline()
pipe.Process(NewCmd("ASKING"))
pipe.Process(cmd)
_, _ = pipe.Exec()
pipe.Close()
ask = false
} else {
client.Process(cmd)
node.Client.Process(cmd)
}
// If there is no (real) error, we are done!
@ -199,10 +274,7 @@ func (c *ClusterClient) process(cmd Cmder) {
// On network errors try random node.
if shouldRetry(err) {
client, err = c.randomClient()
if err != nil {
return
}
node = c.randomNode()
continue
}
@ -210,13 +282,11 @@ func (c *ClusterClient) process(cmd Cmder) {
var addr string
moved, ask, addr = isMovedError(err)
if moved || ask {
if moved && c.slotMasterAddr(slot) != addr {
if moved && c.slotMasterNode(slot).Addr != addr {
c.lazyReloadSlots()
}
client, err = c.getClient(addr)
if err != nil {
return
}
node = c.nodeByAddr(addr)
continue
}
@ -224,64 +294,71 @@ func (c *ClusterClient) process(cmd Cmder) {
}
}
// Closes all clients and returns last error if there are any.
func (c *ClusterClient) resetClients() (retErr error) {
for addr, client := range c.clients {
if err := client.Close(); err != nil && retErr == nil {
// closeClients closes all clients and returns the first error if there are any.
func (c *ClusterClient) closeClients() error {
var retErr error
for _, node := range c.nodes {
if err := node.Client.Close(); err != nil && retErr == nil {
retErr = err
}
delete(c.clients, addr)
}
return retErr
}
func (c *ClusterClient) setSlots(slots []ClusterSlot) {
c.slotsMx.Lock()
seen := make(map[string]struct{})
for _, addr := range c.addrs {
seen[addr] = struct{}{}
}
func (c *ClusterClient) setSlots(cs []ClusterSlot) {
slots := make([][]*clusterNode, hashtag.SlotNumber)
for i := 0; i < hashtag.SlotNumber; i++ {
c.slots[i] = c.slots[i][:0]
slots[i] = nil
}
for _, slot := range slots {
var addrs []string
for _, node := range slot.Nodes {
addrs = append(addrs, node.Addr)
for _, s := range cs {
var nodes []*clusterNode
for _, n := range s.Nodes {
nodes = append(nodes, c.nodeByAddr(n.Addr))
}
for i := slot.Start; i <= slot.End; i++ {
c.slots[i] = addrs
}
for _, node := range slot.Nodes {
if _, ok := seen[node.Addr]; !ok {
c.addrs = append(c.addrs, node.Addr)
seen[node.Addr] = struct{}{}
}
for i := s.Start; i <= s.End; i++ {
slots[i] = nodes
}
}
c.slotsMx.Unlock()
c.mu.Lock()
if !c.closed {
c.slots = slots
}
c.mu.Unlock()
}
func (c *ClusterClient) setNodesLatency() {
nodes := c.getNodes()
for _, node := range nodes {
var latency int
for i := 0; i < 10; i++ {
t1 := time.Now()
node.Client.Ping()
latency += int(time.Since(t1) / time.Millisecond)
}
node.Latency = latency
}
}
func (c *ClusterClient) reloadSlots() {
defer atomic.StoreUint32(&c.reloading, 0)
client, err := c.randomClient()
if err != nil {
internal.Logf("randomClient failed: %s", err)
node := c.randomNode()
if node == nil {
return
}
slots, err := client.ClusterSlots().Result()
slots, err := node.Client.ClusterSlots().Result()
if err != nil {
internal.Logf("ClusterSlots failed: %s", err)
internal.Logf("ClusterSlots on addr=%q failed: %s", node.Addr, err)
return
}
c.setSlots(slots)
if c.opt.RouteByLatency {
c.setNodesLatency()
}
}
func (c *ClusterClient) lazyReloadSlots() {
@ -297,13 +374,14 @@ func (c *ClusterClient) reaper(frequency time.Duration) {
defer ticker.Stop()
for _ = range ticker.C {
if c.closed() {
nodes := c.getNodes()
if nodes == nil {
break
}
var n int
for _, client := range c.getClients() {
nn, err := client.connPool.(*pool.ConnPool).ReapStaleConns()
for _, node := range nodes {
nn, err := node.Client.connPool.(*pool.ConnPool).ReapStaleConns()
if err != nil {
internal.Logf("ReapStaleConns failed: %s", err)
} else {
@ -334,25 +412,21 @@ func (c *ClusterClient) Pipelined(fn func(*Pipeline) error) ([]Cmder, error) {
func (c *ClusterClient) pipelineExec(cmds []Cmder) error {
var retErr error
cmdsMap := make(map[string][]Cmder)
cmdsMap := make(map[*clusterNode][]Cmder)
for _, cmd := range cmds {
slot := hashtag.Slot(cmd.clusterKey())
addr := c.slotMasterAddr(slot)
cmdsMap[addr] = append(cmdsMap[addr], cmd)
_, node := c.cmdSlotAndNode(cmd)
cmdsMap[node] = append(cmdsMap[node], cmd)
}
for attempt := 0; attempt <= c.opt.getMaxRedirects(); attempt++ {
failedCmds := make(map[string][]Cmder)
failedCmds := make(map[*clusterNode][]Cmder)
for addr, cmds := range cmdsMap {
client, err := c.getClient(addr)
if err != nil {
setCmdsErr(cmds, err)
retErr = err
continue
for node, cmds := range cmdsMap {
if node == nil {
node = c.randomNode()
}
cn, err := client.conn()
cn, err := node.Client.conn()
if err != nil {
setCmdsErr(cmds, err)
retErr = err
@ -363,7 +437,7 @@ func (c *ClusterClient) pipelineExec(cmds []Cmder) error {
if err != nil {
retErr = err
}
client.putConn(cn, err, false)
node.Client.putConn(cn, err, false)
}
cmdsMap = failedCmds
@ -373,8 +447,8 @@ func (c *ClusterClient) pipelineExec(cmds []Cmder) error {
}
func (c *ClusterClient) execClusterCmds(
cn *pool.Conn, cmds []Cmder, failedCmds map[string][]Cmder,
) (map[string][]Cmder, error) {
cn *pool.Conn, cmds []Cmder, failedCmds map[*clusterNode][]Cmder,
) (map[*clusterNode][]Cmder, error) {
if err := writeCmd(cn, cmds...); err != nil {
setCmdsErr(cmds, err)
return failedCmds, err
@ -388,15 +462,17 @@ func (c *ClusterClient) execClusterCmds(
}
if isNetworkError(err) {
cmd.reset()
failedCmds[""] = append(failedCmds[""], cmds[i:]...)
failedCmds[nil] = append(failedCmds[nil], cmds[i:]...)
break
} else if moved, ask, addr := isMovedError(err); moved {
c.lazyReloadSlots()
cmd.reset()
failedCmds[addr] = append(failedCmds[addr], cmd)
node := c.nodeByAddr(addr)
failedCmds[node] = append(failedCmds[node], cmd)
} else if ask {
cmd.reset()
failedCmds[addr] = append(failedCmds[addr], NewCmd("ASKING"), cmd)
node := c.nodeByAddr(addr)
failedCmds[node] = append(failedCmds[node], NewCmd("ASKING"), cmd)
} else if firstCmdErr == nil {
firstCmdErr = err
}
@ -418,6 +494,12 @@ type ClusterOptions struct {
// Default is 16.
MaxRedirects int
// Enables read queries for a connection to a Redis Cluster slave node.
ReadOnly bool
// Enables routing read-only queries to the closest master or slave node.
RouteByLatency bool
// Following options are copied from Options struct.
Password string
@ -446,6 +528,7 @@ func (opt *ClusterOptions) getMaxRedirects() int {
func (opt *ClusterOptions) clientOptions() *Options {
return &Options{
Password: opt.Password,
ReadOnly: opt.ReadOnly,
DialTimeout: opt.DialTimeout,
ReadTimeout: opt.ReadTimeout,
@ -454,6 +537,7 @@ func (opt *ClusterOptions) clientOptions() *Options {
PoolSize: opt.PoolSize,
PoolTimeout: opt.PoolTimeout,
IdleTimeout: opt.IdleTimeout,
// IdleCheckFrequency is not copied to disable reaper
}
}

View File

@ -6,16 +6,21 @@ import (
)
func (c *ClusterClient) SlotAddrs(slot int) []string {
return c.slotAddrs(slot)
var addrs []string
for _, n := range c.slotNodes(slot) {
addrs = append(addrs, n.Addr)
}
return addrs
}
// SwapSlot swaps a slot's master/slave address
// for testing MOVED redirects
func (c *ClusterClient) SwapSlot(pos int) []string {
c.slotsMx.Lock()
defer c.slotsMx.Unlock()
c.slots[pos][0], c.slots[pos][1] = c.slots[pos][1], c.slots[pos][0]
return c.slots[pos]
func (c *ClusterClient) SwapSlotNodes(slot int) []string {
c.mu.Lock()
nodes := c.slots[slot]
nodes[0], nodes[1] = nodes[1], nodes[0]
c.mu.Unlock()
return c.SlotAddrs(slot)
}
var _ = Describe("ClusterClient", func() {
@ -42,19 +47,26 @@ var _ = Describe("ClusterClient", func() {
It("should initialize", func() {
Expect(subject.addrs).To(HaveLen(3))
Expect(subject.slots).To(HaveLen(16384))
})
It("should update slots cache", func() {
populate()
Expect(subject.slots[0]).To(Equal([]string{"127.0.0.1:7000", "127.0.0.1:7004"}))
Expect(subject.slots[4095]).To(Equal([]string{"127.0.0.1:7000", "127.0.0.1:7004"}))
Expect(subject.slots[4096]).To(Equal([]string{"127.0.0.1:7001", "127.0.0.1:7005"}))
Expect(subject.slots[8191]).To(Equal([]string{"127.0.0.1:7001", "127.0.0.1:7005"}))
Expect(subject.slots[8192]).To(Equal([]string{"127.0.0.1:7002", "127.0.0.1:7006"}))
Expect(subject.slots[12287]).To(Equal([]string{"127.0.0.1:7002", "127.0.0.1:7006"}))
Expect(subject.slots[12288]).To(Equal([]string{"127.0.0.1:7003", "127.0.0.1:7007"}))
Expect(subject.slots[16383]).To(Equal([]string{"127.0.0.1:7003", "127.0.0.1:7007"}))
Expect(subject.slots[0][0].Addr).To(Equal("127.0.0.1:7000"))
Expect(subject.slots[0][1].Addr).To(Equal("127.0.0.1:7004"))
Expect(subject.slots[4095][0].Addr).To(Equal("127.0.0.1:7000"))
Expect(subject.slots[4095][1].Addr).To(Equal("127.0.0.1:7004"))
Expect(subject.slots[4096][0].Addr).To(Equal("127.0.0.1:7001"))
Expect(subject.slots[4096][1].Addr).To(Equal("127.0.0.1:7005"))
Expect(subject.slots[8191][0].Addr).To(Equal("127.0.0.1:7001"))
Expect(subject.slots[8191][1].Addr).To(Equal("127.0.0.1:7005"))
Expect(subject.slots[8192][0].Addr).To(Equal("127.0.0.1:7002"))
Expect(subject.slots[8192][1].Addr).To(Equal("127.0.0.1:7006"))
Expect(subject.slots[12287][0].Addr).To(Equal("127.0.0.1:7002"))
Expect(subject.slots[12287][1].Addr).To(Equal("127.0.0.1:7006"))
Expect(subject.slots[12288][0].Addr).To(Equal("127.0.0.1:7003"))
Expect(subject.slots[12288][1].Addr).To(Equal("127.0.0.1:7007"))
Expect(subject.slots[16383][0].Addr).To(Equal("127.0.0.1:7003"))
Expect(subject.slots[16383][1].Addr).To(Equal("127.0.0.1:7007"))
Expect(subject.addrs).To(Equal([]string{
"127.0.0.1:6379",
"127.0.0.1:7003",
@ -71,11 +83,9 @@ var _ = Describe("ClusterClient", func() {
It("should close", func() {
populate()
Expect(subject.Close()).NotTo(HaveOccurred())
Expect(subject.clients).To(BeEmpty())
Expect(subject.slots[0]).To(BeEmpty())
Expect(subject.slots[8191]).To(BeEmpty())
Expect(subject.slots[8192]).To(BeEmpty())
Expect(subject.slots[16383]).To(BeEmpty())
Expect(subject.addrs).To(BeEmpty())
Expect(subject.nodes).To(BeEmpty())
Expect(subject.slots).To(BeEmpty())
Expect(subject.Ping().Err().Error()).To(Equal("redis: client is closed"))
})
})

View File

@ -301,7 +301,7 @@ var _ = Describe("Cluster", func() {
})
It("should CLUSTER READONLY", func() {
res, err := cluster.primary().Readonly().Result()
res, err := cluster.primary().ReadOnly().Result()
Expect(err).NotTo(HaveOccurred())
Expect(res).To(Equal("OK"))
})
@ -353,7 +353,7 @@ var _ = Describe("Cluster", func() {
Expect(client.Set("A", "VALUE", 0).Err()).NotTo(HaveOccurred())
slot := hashtag.Slot("A")
Expect(client.SwapSlot(slot)).To(Equal([]string{"127.0.0.1:8224", "127.0.0.1:8221"}))
Expect(client.SwapSlotNodes(slot)).To(Equal([]string{"127.0.0.1:8224", "127.0.0.1:8221"}))
val, err := client.Get("A").Result()
Expect(err).NotTo(HaveOccurred())
@ -361,7 +361,7 @@ var _ = Describe("Cluster", func() {
Eventually(func() []string {
return client.SlotAddrs(slot)
}, "5s").Should(Equal([]string{"127.0.0.1:8221", "127.0.0.1:8224"}))
}, "10s").Should(Equal([]string{"127.0.0.1:8221", "127.0.0.1:8224"}))
})
It("should return error when there are no attempts left", func() {
@ -371,7 +371,7 @@ var _ = Describe("Cluster", func() {
})
slot := hashtag.Slot("A")
Expect(client.SwapSlot(slot)).To(Equal([]string{"127.0.0.1:8224", "127.0.0.1:8221"}))
Expect(client.SwapSlotNodes(slot)).To(Equal([]string{"127.0.0.1:8224", "127.0.0.1:8221"}))
err := client.Get("A").Err()
Expect(err).To(HaveOccurred())
@ -435,7 +435,7 @@ var _ = Describe("Cluster", func() {
It("performs multi-pipelines", func() {
slot := hashtag.Slot("A")
Expect(client.SwapSlot(slot)).To(Equal([]string{"127.0.0.1:8224", "127.0.0.1:8221"}))
Expect(client.SwapSlotNodes(slot)).To(Equal([]string{"127.0.0.1:8224", "127.0.0.1:8221"}))
pipe := client.Pipeline()
defer pipe.Close()

View File

@ -30,12 +30,12 @@ var (
type Cmder interface {
args() []interface{}
arg(int) string
readReply(*pool.Conn) error
setErr(error)
reset()
readTimeout() *time.Duration
clusterKey() string
Err() error
fmt.Stringer
@ -92,10 +92,7 @@ func cmdString(cmd Cmder, val interface{}) string {
type baseCmd struct {
_args []interface{}
err error
_clusterKeyPos int
err error
_readTimeout *time.Duration
}
@ -111,6 +108,15 @@ func (cmd *baseCmd) args() []interface{} {
return cmd._args
}
func (cmd *baseCmd) arg(pos int) string {
if len(cmd._args) > pos {
if s, ok := cmd._args[pos].(string); ok {
return s
}
}
return ""
}
func (cmd *baseCmd) readTimeout() *time.Duration {
return cmd._readTimeout
}
@ -119,17 +125,14 @@ func (cmd *baseCmd) setReadTimeout(d time.Duration) {
cmd._readTimeout = &d
}
func (cmd *baseCmd) clusterKey() string {
if cmd._clusterKeyPos > 0 && cmd._clusterKeyPos < len(cmd._args) {
return fmt.Sprint(cmd._args[cmd._clusterKeyPos])
}
return ""
}
func (cmd *baseCmd) setErr(e error) {
cmd.err = e
}
func newBaseCmd(args []interface{}) baseCmd {
return baseCmd{_args: args}
}
//------------------------------------------------------------------------------
type Cmd struct {
@ -139,7 +142,7 @@ type Cmd struct {
}
func NewCmd(args ...interface{}) *Cmd {
return &Cmd{baseCmd: baseCmd{_args: args}}
return &Cmd{baseCmd: newBaseCmd(args)}
}
func (cmd *Cmd) reset() {
@ -183,7 +186,8 @@ type SliceCmd struct {
}
func NewSliceCmd(args ...interface{}) *SliceCmd {
return &SliceCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &SliceCmd{baseCmd: cmd}
}
func (cmd *SliceCmd) reset() {
@ -222,11 +226,8 @@ type StatusCmd struct {
}
func NewStatusCmd(args ...interface{}) *StatusCmd {
return &StatusCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
}
func newKeylessStatusCmd(args ...interface{}) *StatusCmd {
return &StatusCmd{baseCmd: baseCmd{_args: args}}
cmd := newBaseCmd(args)
return &StatusCmd{baseCmd: cmd}
}
func (cmd *StatusCmd) reset() {
@ -260,7 +261,8 @@ type IntCmd struct {
}
func NewIntCmd(args ...interface{}) *IntCmd {
return &IntCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &IntCmd{baseCmd: cmd}
}
func (cmd *IntCmd) reset() {
@ -295,9 +297,10 @@ type DurationCmd struct {
}
func NewDurationCmd(precision time.Duration, args ...interface{}) *DurationCmd {
cmd := newBaseCmd(args)
return &DurationCmd{
precision: precision,
baseCmd: baseCmd{_args: args, _clusterKeyPos: 1},
baseCmd: cmd,
}
}
@ -337,7 +340,8 @@ type BoolCmd struct {
}
func NewBoolCmd(args ...interface{}) *BoolCmd {
return &BoolCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &BoolCmd{baseCmd: cmd}
}
func (cmd *BoolCmd) reset() {
@ -393,7 +397,8 @@ type StringCmd struct {
}
func NewStringCmd(args ...interface{}) *StringCmd {
return &StringCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &StringCmd{baseCmd: cmd}
}
func (cmd *StringCmd) reset() {
@ -468,7 +473,8 @@ type FloatCmd struct {
}
func NewFloatCmd(args ...interface{}) *FloatCmd {
return &FloatCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &FloatCmd{baseCmd: cmd}
}
func (cmd *FloatCmd) reset() {
@ -502,7 +508,8 @@ type StringSliceCmd struct {
}
func NewStringSliceCmd(args ...interface{}) *StringSliceCmd {
return &StringSliceCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &StringSliceCmd{baseCmd: cmd}
}
func (cmd *StringSliceCmd) reset() {
@ -541,7 +548,8 @@ type BoolSliceCmd struct {
}
func NewBoolSliceCmd(args ...interface{}) *BoolSliceCmd {
return &BoolSliceCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &BoolSliceCmd{baseCmd: cmd}
}
func (cmd *BoolSliceCmd) reset() {
@ -580,7 +588,8 @@ type StringStringMapCmd struct {
}
func NewStringStringMapCmd(args ...interface{}) *StringStringMapCmd {
return &StringStringMapCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &StringStringMapCmd{baseCmd: cmd}
}
func (cmd *StringStringMapCmd) reset() {
@ -619,7 +628,8 @@ type StringIntMapCmd struct {
}
func NewStringIntMapCmd(args ...interface{}) *StringIntMapCmd {
return &StringIntMapCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &StringIntMapCmd{baseCmd: cmd}
}
func (cmd *StringIntMapCmd) Val() map[string]int64 {
@ -658,7 +668,8 @@ type ZSliceCmd struct {
}
func NewZSliceCmd(args ...interface{}) *ZSliceCmd {
return &ZSliceCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &ZSliceCmd{baseCmd: cmd}
}
func (cmd *ZSliceCmd) reset() {
@ -698,8 +709,9 @@ type ScanCmd struct {
}
func NewScanCmd(args ...interface{}) *ScanCmd {
cmd := newBaseCmd(args)
return &ScanCmd{
baseCmd: baseCmd{_args: args, _clusterKeyPos: 1},
baseCmd: cmd,
}
}
@ -752,7 +764,8 @@ type ClusterSlotsCmd struct {
}
func NewClusterSlotsCmd(args ...interface{}) *ClusterSlotsCmd {
return &ClusterSlotsCmd{baseCmd: baseCmd{_args: args, _clusterKeyPos: 1}}
cmd := newBaseCmd(args)
return &ClusterSlotsCmd{baseCmd: cmd}
}
func (cmd *ClusterSlotsCmd) Val() []ClusterSlot {
@ -833,12 +846,10 @@ func NewGeoLocationCmd(q *GeoRadiusQuery, args ...interface{}) *GeoLocationCmd {
if q.Sort != "" {
args = append(args, q.Sort)
}
cmd := newBaseCmd(args)
return &GeoLocationCmd{
baseCmd: baseCmd{
_args: args,
_clusterKeyPos: 1,
},
q: q,
baseCmd: cmd,
q: q,
}
}
@ -868,3 +879,53 @@ func (cmd *GeoLocationCmd) readReply(cn *pool.Conn) error {
cmd.locations = reply.([]GeoLocation)
return nil
}
//------------------------------------------------------------------------------
type CommandInfo struct {
Name string
Arity int8
Flags []string
FirstKeyPos int8
LastKeyPos int8
StepCount int8
ReadOnly bool
}
type CommandsInfoCmd struct {
baseCmd
val map[string]*CommandInfo
}
func NewCommandsInfoCmd(args ...interface{}) *CommandsInfoCmd {
cmd := newBaseCmd(args)
return &CommandsInfoCmd{baseCmd: cmd}
}
func (cmd *CommandsInfoCmd) Val() map[string]*CommandInfo {
return cmd.val
}
func (cmd *CommandsInfoCmd) Result() (map[string]*CommandInfo, error) {
return cmd.Val(), cmd.Err()
}
func (cmd *CommandsInfoCmd) String() string {
return cmdString(cmd, cmd.val)
}
func (cmd *CommandsInfoCmd) reset() {
cmd.val = nil
cmd.err = nil
}
func (cmd *CommandsInfoCmd) readReply(cn *pool.Conn) error {
v, err := readArrayReply(cn, commandInfoSliceParser)
if err != nil {
cmd.err = err
return err
}
cmd.val = v.(map[string]*CommandInfo)
return nil
}

View File

@ -21,10 +21,10 @@ var _ = Describe("Cmd", func() {
It("implements Stringer", func() {
set := client.Set("foo", "bar", 0)
Expect(set.String()).To(Equal("SET foo bar: OK"))
Expect(set.String()).To(Equal("set foo bar: OK"))
get := client.Get("foo")
Expect(get.String()).To(Equal("GET foo: bar"))
Expect(get.String()).To(Equal("get foo: bar"))
})
It("has val/err", func() {

File diff suppressed because it is too large Load Diff

View File

@ -2729,6 +2729,7 @@ var _ = Describe("Commands", func() {
})
Describe("json marshaling/unmarshaling", func() {
BeforeEach(func() {
value := &numberStruct{Number: 42}
err := client.Set("key", value, 0).Err()
@ -2744,12 +2745,30 @@ var _ = Describe("Commands", func() {
It("should scan custom values using json", func() {
value := &numberStruct{}
err := client.Get("key").Scan(value)
Expect(err).To(BeNil())
Expect(err).NotTo(HaveOccurred())
Expect(value.Number).To(Equal(42))
})
})
Describe("Command", func() {
It("returns map of commands", func() {
cmds, err := client.Command().Result()
Expect(err).NotTo(HaveOccurred())
Expect(len(cmds)).To(BeNumerically("~", 173, 5))
cmd := cmds["mget"]
Expect(cmd.Name).To(Equal("mget"))
Expect(cmd.Arity).To(Equal(int8(-2)))
Expect(cmd.Flags).To(Equal([]string{"readonly"}))
Expect(cmd.FirstKeyPos).To(Equal(int8(1)))
Expect(cmd.LastKeyPos).To(Equal(int8(-1)))
Expect(cmd.StepCount).To(Equal(int8(1)))
})
})
})
type numberStruct struct {

View File

@ -53,6 +53,9 @@ type Options struct {
// The frequency of idle checks.
// Default is 1 minute.
IdleCheckFrequency time.Duration
// Enables read queries for a connection to a Redis Cluster slave node.
ReadOnly bool
}
func (opt *Options) getNetwork() string {

View File

@ -627,8 +627,8 @@ func clusterSlotsParser(cn *pool.Conn, slotNum int64) (interface{}, error) {
func newGeoLocationParser(q *GeoRadiusQuery) multiBulkParser {
return func(cn *pool.Conn, n int64) (interface{}, error) {
var loc GeoLocation
var err error
loc.Name, err = readStringReply(cn)
if err != nil {
return nil, err
@ -690,3 +690,70 @@ func newGeoLocationSliceParser(q *GeoRadiusQuery) multiBulkParser {
return locs, nil
}
}
func commandInfoParser(cn *pool.Conn, n int64) (interface{}, error) {
var cmd CommandInfo
var err error
if n != 6 {
return nil, fmt.Errorf("redis: got %d elements in COMMAND reply, wanted 6")
}
cmd.Name, err = readStringReply(cn)
if err != nil {
return nil, err
}
arity, err := readIntReply(cn)
if err != nil {
return nil, err
}
cmd.Arity = int8(arity)
flags, err := readReply(cn, stringSliceParser)
if err != nil {
return nil, err
}
cmd.Flags = flags.([]string)
firstKeyPos, err := readIntReply(cn)
if err != nil {
return nil, err
}
cmd.FirstKeyPos = int8(firstKeyPos)
lastKeyPos, err := readIntReply(cn)
if err != nil {
return nil, err
}
cmd.LastKeyPos = int8(lastKeyPos)
stepCount, err := readIntReply(cn)
if err != nil {
return nil, err
}
cmd.StepCount = int8(stepCount)
for _, flag := range cmd.Flags {
if flag == "readonly" {
cmd.ReadOnly = true
break
}
}
return &cmd, nil
}
func commandInfoSliceParser(cn *pool.Conn, n int64) (interface{}, error) {
m := make(map[string]*CommandInfo, n)
for i := int64(0); i < n; i++ {
v, err := readReply(cn, commandInfoParser)
if err != nil {
return nil, err
}
vv := v.(*CommandInfo)
m[vv.Name] = vv
}
return m, nil
}

View File

@ -52,7 +52,7 @@ func (c *baseClient) putConn(cn *pool.Conn, err error, allowTimeout bool) bool {
func (c *baseClient) initConn(cn *pool.Conn) error {
cn.Inited = true
if c.opt.Password == "" && c.opt.DB == 0 {
if c.opt.Password == "" && c.opt.DB == 0 && !c.opt.ReadOnly {
return nil
}
@ -71,6 +71,12 @@ func (c *baseClient) initConn(cn *pool.Conn) error {
}
}
if c.opt.ReadOnly {
if err := client.ReadOnly().Err(); err != nil {
return err
}
}
return nil
}

60
ring.go
View File

@ -115,10 +115,13 @@ type Ring struct {
opt *RingOptions
nreplicas int
mx sync.RWMutex
mu sync.RWMutex
hash *consistenthash.Map
shards map[string]*ringShard
cmdsInfo map[string]*CommandInfo
cmdsInfoOnce *sync.Once
closed bool
}
@ -130,6 +133,8 @@ func NewRing(opt *RingOptions) *Ring {
hash: consistenthash.New(nreplicas, nil),
shards: make(map[string]*ringShard),
cmdsInfoOnce: new(sync.Once),
}
ring.commandable.process = ring.process
for name, addr := range opt.Addrs {
@ -141,15 +146,40 @@ func NewRing(opt *RingOptions) *Ring {
return ring
}
func (ring *Ring) cmdInfo(name string) *CommandInfo {
ring.cmdsInfoOnce.Do(func() {
for _, shard := range ring.shards {
cmdsInfo, err := shard.Client.Command().Result()
if err == nil {
ring.cmdsInfo = cmdsInfo
return
}
}
ring.cmdsInfoOnce = &sync.Once{}
})
if ring.cmdsInfo == nil {
return nil
}
return ring.cmdsInfo[name]
}
func (ring *Ring) cmdFirstKey(cmd Cmder) string {
cmdInfo := ring.cmdInfo(cmd.arg(0))
if cmdInfo == nil {
return ""
}
return cmd.arg(int(cmdInfo.FirstKeyPos))
}
func (ring *Ring) addClient(name string, cl *Client) {
ring.mx.Lock()
ring.mu.Lock()
ring.hash.Add(name)
ring.shards[name] = &ringShard{Client: cl}
ring.mx.Unlock()
ring.mu.Unlock()
}
func (ring *Ring) getClient(key string) (*Client, error) {
ring.mx.RLock()
ring.mu.RLock()
if ring.closed {
return nil, pool.ErrClosed
@ -157,17 +187,17 @@ func (ring *Ring) getClient(key string) (*Client, error) {
name := ring.hash.Get(hashtag.Key(key))
if name == "" {
ring.mx.RUnlock()
ring.mu.RUnlock()
return nil, errRingShardsDown
}
cl := ring.shards[name].Client
ring.mx.RUnlock()
ring.mu.RUnlock()
return cl, nil
}
func (ring *Ring) process(cmd Cmder) {
cl, err := ring.getClient(cmd.clusterKey())
cl, err := ring.getClient(ring.cmdFirstKey(cmd))
if err != nil {
cmd.setErr(err)
return
@ -177,8 +207,8 @@ func (ring *Ring) process(cmd Cmder) {
// rebalance removes dead shards from the ring.
func (ring *Ring) rebalance() {
defer ring.mx.Unlock()
ring.mx.Lock()
defer ring.mu.Unlock()
ring.mu.Lock()
ring.hash = consistenthash.New(ring.nreplicas, nil)
for name, shard := range ring.shards {
@ -195,10 +225,10 @@ func (ring *Ring) heartbeat() {
for _ = range ticker.C {
var rebalance bool
ring.mx.RLock()
ring.mu.RLock()
if ring.closed {
ring.mx.RUnlock()
ring.mu.RUnlock()
break
}
@ -210,7 +240,7 @@ func (ring *Ring) heartbeat() {
}
}
ring.mx.RUnlock()
ring.mu.RUnlock()
if rebalance {
ring.rebalance()
@ -223,8 +253,8 @@ func (ring *Ring) heartbeat() {
// It is rare to Close a Ring, as the Ring is meant to be long-lived
// and shared between many goroutines.
func (ring *Ring) Close() (retErr error) {
defer ring.mx.Unlock()
ring.mx.Lock()
defer ring.mu.Unlock()
ring.mu.Lock()
if ring.closed {
return nil
@ -259,7 +289,7 @@ func (ring *Ring) pipelineExec(cmds []Cmder) error {
cmdsMap := make(map[string][]Cmder)
for _, cmd := range cmds {
name := ring.hash.Get(hashtag.Key(cmd.clusterKey()))
name := ring.hash.Get(hashtag.Key(ring.cmdFirstKey(cmd)))
if name == "" {
cmd.setErr(errRingShardsDown)
if retErr == nil {