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gitea/vendor/github.com/go-redis/redis/v7/sentinel.go

510 lines
12 KiB
Go

package redis
import (
"context"
"crypto/tls"
"errors"
"net"
"strings"
"sync"
"time"
"github.com/go-redis/redis/v7/internal"
"github.com/go-redis/redis/v7/internal/pool"
)
//------------------------------------------------------------------------------
// FailoverOptions are used to configure a failover client and should
// be passed to NewFailoverClient.
type FailoverOptions struct {
// The master name.
MasterName string
// A seed list of host:port addresses of sentinel nodes.
SentinelAddrs []string
SentinelUsername string
SentinelPassword string
// Following options are copied from Options struct.
Dialer func(ctx context.Context, network, addr string) (net.Conn, error)
OnConnect func(*Conn) error
Username string
Password string
DB int
MaxRetries int
MinRetryBackoff time.Duration
MaxRetryBackoff time.Duration
DialTimeout time.Duration
ReadTimeout time.Duration
WriteTimeout time.Duration
PoolSize int
MinIdleConns int
MaxConnAge time.Duration
PoolTimeout time.Duration
IdleTimeout time.Duration
IdleCheckFrequency time.Duration
TLSConfig *tls.Config
}
func (opt *FailoverOptions) options() *Options {
return &Options{
Addr: "FailoverClient",
Dialer: opt.Dialer,
OnConnect: opt.OnConnect,
DB: opt.DB,
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,
PoolTimeout: opt.PoolTimeout,
IdleTimeout: opt.IdleTimeout,
IdleCheckFrequency: opt.IdleCheckFrequency,
MinIdleConns: opt.MinIdleConns,
MaxConnAge: opt.MaxConnAge,
TLSConfig: opt.TLSConfig,
}
}
// NewFailoverClient returns a Redis client that uses Redis Sentinel
// for automatic failover. It's safe for concurrent use by multiple
// goroutines.
func NewFailoverClient(failoverOpt *FailoverOptions) *Client {
opt := failoverOpt.options()
opt.init()
failover := &sentinelFailover{
masterName: failoverOpt.MasterName,
sentinelAddrs: failoverOpt.SentinelAddrs,
username: failoverOpt.SentinelUsername,
password: failoverOpt.SentinelPassword,
opt: opt,
}
c := Client{
baseClient: newBaseClient(opt, failover.Pool()),
ctx: context.Background(),
}
c.cmdable = c.Process
c.onClose = failover.Close
return &c
}
//------------------------------------------------------------------------------
type SentinelClient struct {
*baseClient
ctx context.Context
}
func NewSentinelClient(opt *Options) *SentinelClient {
opt.init()
c := &SentinelClient{
baseClient: &baseClient{
opt: opt,
connPool: newConnPool(opt),
},
ctx: context.Background(),
}
return c
}
func (c *SentinelClient) Context() context.Context {
return c.ctx
}
func (c *SentinelClient) WithContext(ctx context.Context) *SentinelClient {
if ctx == nil {
panic("nil context")
}
clone := *c
clone.ctx = ctx
return &clone
}
func (c *SentinelClient) Process(cmd Cmder) error {
return c.ProcessContext(c.ctx, cmd)
}
func (c *SentinelClient) ProcessContext(ctx context.Context, cmd Cmder) error {
return c.baseClient.process(ctx, cmd)
}
func (c *SentinelClient) pubSub() *PubSub {
pubsub := &PubSub{
opt: c.opt,
newConn: func(channels []string) (*pool.Conn, error) {
return c.newConn(context.TODO())
},
closeConn: c.connPool.CloseConn,
}
pubsub.init()
return pubsub
}
// Ping is used to test if a connection is still alive, or to
// measure latency.
func (c *SentinelClient) Ping() *StringCmd {
cmd := NewStringCmd("ping")
_ = c.Process(cmd)
return cmd
}
// Subscribe subscribes the client to the specified channels.
// Channels can be omitted to create empty subscription.
func (c *SentinelClient) Subscribe(channels ...string) *PubSub {
pubsub := c.pubSub()
if len(channels) > 0 {
_ = pubsub.Subscribe(channels...)
}
return pubsub
}
// PSubscribe subscribes the client to the given patterns.
// Patterns can be omitted to create empty subscription.
func (c *SentinelClient) PSubscribe(channels ...string) *PubSub {
pubsub := c.pubSub()
if len(channels) > 0 {
_ = pubsub.PSubscribe(channels...)
}
return pubsub
}
func (c *SentinelClient) GetMasterAddrByName(name string) *StringSliceCmd {
cmd := NewStringSliceCmd("sentinel", "get-master-addr-by-name", name)
_ = c.Process(cmd)
return cmd
}
func (c *SentinelClient) Sentinels(name string) *SliceCmd {
cmd := NewSliceCmd("sentinel", "sentinels", name)
_ = c.Process(cmd)
return cmd
}
// Failover forces a failover as if the master was not reachable, and without
// asking for agreement to other Sentinels.
func (c *SentinelClient) Failover(name string) *StatusCmd {
cmd := NewStatusCmd("sentinel", "failover", name)
_ = c.Process(cmd)
return cmd
}
// Reset resets all the masters with matching name. The pattern argument is a
// glob-style pattern. The reset process clears any previous state in a master
// (including a failover in progress), and removes every slave and sentinel
// already discovered and associated with the master.
func (c *SentinelClient) Reset(pattern string) *IntCmd {
cmd := NewIntCmd("sentinel", "reset", pattern)
_ = c.Process(cmd)
return cmd
}
// FlushConfig forces Sentinel to rewrite its configuration on disk, including
// the current Sentinel state.
func (c *SentinelClient) FlushConfig() *StatusCmd {
cmd := NewStatusCmd("sentinel", "flushconfig")
_ = c.Process(cmd)
return cmd
}
// Master shows the state and info of the specified master.
func (c *SentinelClient) Master(name string) *StringStringMapCmd {
cmd := NewStringStringMapCmd("sentinel", "master", name)
_ = c.Process(cmd)
return cmd
}
// Masters shows a list of monitored masters and their state.
func (c *SentinelClient) Masters() *SliceCmd {
cmd := NewSliceCmd("sentinel", "masters")
_ = c.Process(cmd)
return cmd
}
// Slaves shows a list of slaves for the specified master and their state.
func (c *SentinelClient) Slaves(name string) *SliceCmd {
cmd := NewSliceCmd("sentinel", "slaves", name)
_ = c.Process(cmd)
return cmd
}
// CkQuorum checks if the current Sentinel configuration is able to reach the
// quorum needed to failover a master, and the majority needed to authorize the
// failover. This command should be used in monitoring systems to check if a
// Sentinel deployment is ok.
func (c *SentinelClient) CkQuorum(name string) *StringCmd {
cmd := NewStringCmd("sentinel", "ckquorum", name)
_ = c.Process(cmd)
return cmd
}
// Monitor tells the Sentinel to start monitoring a new master with the specified
// name, ip, port, and quorum.
func (c *SentinelClient) Monitor(name, ip, port, quorum string) *StringCmd {
cmd := NewStringCmd("sentinel", "monitor", name, ip, port, quorum)
_ = c.Process(cmd)
return cmd
}
// Set is used in order to change configuration parameters of a specific master.
func (c *SentinelClient) Set(name, option, value string) *StringCmd {
cmd := NewStringCmd("sentinel", "set", name, option, value)
_ = c.Process(cmd)
return cmd
}
// Remove is used in order to remove the specified master: the master will no
// longer be monitored, and will totally be removed from the internal state of
// the Sentinel.
func (c *SentinelClient) Remove(name string) *StringCmd {
cmd := NewStringCmd("sentinel", "remove", name)
_ = c.Process(cmd)
return cmd
}
type sentinelFailover struct {
sentinelAddrs []string
opt *Options
username string
password string
pool *pool.ConnPool
poolOnce sync.Once
mu sync.RWMutex
masterName string
_masterAddr string
sentinel *SentinelClient
pubsub *PubSub
}
func (c *sentinelFailover) Close() error {
c.mu.Lock()
defer c.mu.Unlock()
if c.sentinel != nil {
return c.closeSentinel()
}
return nil
}
func (c *sentinelFailover) closeSentinel() error {
firstErr := c.pubsub.Close()
c.pubsub = nil
err := c.sentinel.Close()
if err != nil && firstErr == nil {
firstErr = err
}
c.sentinel = nil
return firstErr
}
func (c *sentinelFailover) Pool() *pool.ConnPool {
c.poolOnce.Do(func() {
opt := *c.opt
opt.Dialer = c.dial
c.pool = newConnPool(&opt)
})
return c.pool
}
func (c *sentinelFailover) dial(ctx context.Context, network, _ string) (net.Conn, error) {
addr, err := c.MasterAddr()
if err != nil {
return nil, err
}
if c.opt.Dialer != nil {
return c.opt.Dialer(ctx, network, addr)
}
return net.DialTimeout("tcp", addr, c.opt.DialTimeout)
}
func (c *sentinelFailover) MasterAddr() (string, error) {
addr, err := c.masterAddr()
if err != nil {
return "", err
}
c.switchMaster(addr)
return addr, nil
}
func (c *sentinelFailover) masterAddr() (string, error) {
c.mu.RLock()
sentinel := c.sentinel
c.mu.RUnlock()
if sentinel != nil {
addr := c.getMasterAddr(sentinel)
if addr != "" {
return addr, nil
}
}
c.mu.Lock()
defer c.mu.Unlock()
if c.sentinel != nil {
addr := c.getMasterAddr(c.sentinel)
if addr != "" {
return addr, nil
}
_ = c.closeSentinel()
}
for i, sentinelAddr := range c.sentinelAddrs {
sentinel := NewSentinelClient(&Options{
Addr: sentinelAddr,
Dialer: c.opt.Dialer,
Username: c.username,
Password: c.password,
MaxRetries: c.opt.MaxRetries,
DialTimeout: c.opt.DialTimeout,
ReadTimeout: c.opt.ReadTimeout,
WriteTimeout: c.opt.WriteTimeout,
PoolSize: c.opt.PoolSize,
PoolTimeout: c.opt.PoolTimeout,
IdleTimeout: c.opt.IdleTimeout,
IdleCheckFrequency: c.opt.IdleCheckFrequency,
TLSConfig: c.opt.TLSConfig,
})
masterAddr, err := sentinel.GetMasterAddrByName(c.masterName).Result()
if err != nil {
internal.Logger.Printf("sentinel: GetMasterAddrByName master=%q failed: %s",
c.masterName, err)
_ = sentinel.Close()
continue
}
// Push working sentinel to the top.
c.sentinelAddrs[0], c.sentinelAddrs[i] = c.sentinelAddrs[i], c.sentinelAddrs[0]
c.setSentinel(sentinel)
addr := net.JoinHostPort(masterAddr[0], masterAddr[1])
return addr, nil
}
return "", errors.New("redis: all sentinels are unreachable")
}
func (c *sentinelFailover) getMasterAddr(sentinel *SentinelClient) string {
addr, err := sentinel.GetMasterAddrByName(c.masterName).Result()
if err != nil {
internal.Logger.Printf("sentinel: GetMasterAddrByName name=%q failed: %s",
c.masterName, err)
return ""
}
return net.JoinHostPort(addr[0], addr[1])
}
func (c *sentinelFailover) switchMaster(addr string) {
c.mu.RLock()
masterAddr := c._masterAddr
c.mu.RUnlock()
if masterAddr == addr {
return
}
c.mu.Lock()
defer c.mu.Unlock()
if c._masterAddr == addr {
return
}
internal.Logger.Printf("sentinel: new master=%q addr=%q",
c.masterName, addr)
_ = c.Pool().Filter(func(cn *pool.Conn) bool {
return cn.RemoteAddr().String() != addr
})
c._masterAddr = addr
}
func (c *sentinelFailover) setSentinel(sentinel *SentinelClient) {
if c.sentinel != nil {
panic("not reached")
}
c.sentinel = sentinel
c.discoverSentinels()
c.pubsub = sentinel.Subscribe("+switch-master")
go c.listen(c.pubsub)
}
func (c *sentinelFailover) discoverSentinels() {
sentinels, err := c.sentinel.Sentinels(c.masterName).Result()
if err != nil {
internal.Logger.Printf("sentinel: Sentinels master=%q failed: %s", c.masterName, err)
return
}
for _, sentinel := range sentinels {
vals := sentinel.([]interface{})
for i := 0; i < len(vals); i += 2 {
key := vals[i].(string)
if key == "name" {
sentinelAddr := vals[i+1].(string)
if !contains(c.sentinelAddrs, sentinelAddr) {
internal.Logger.Printf("sentinel: discovered new sentinel=%q for master=%q",
sentinelAddr, c.masterName)
c.sentinelAddrs = append(c.sentinelAddrs, sentinelAddr)
}
}
}
}
}
func (c *sentinelFailover) listen(pubsub *PubSub) {
ch := pubsub.Channel()
for {
msg, ok := <-ch
if !ok {
break
}
if msg.Channel == "+switch-master" {
parts := strings.Split(msg.Payload, " ")
if parts[0] != c.masterName {
internal.Logger.Printf("sentinel: ignore addr for master=%q", parts[0])
continue
}
addr := net.JoinHostPort(parts[3], parts[4])
c.switchMaster(addr)
}
}
}
func contains(slice []string, str string) bool {
for _, s := range slice {
if s == str {
return true
}
}
return false
}