vikunja-api/vendor/github.com/go-redis/redis/v7/sentinel.go

504 lines
12 KiB
Go
Raw Normal View History

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
SentinelPassword string
// Following options are copied from Options struct.
Dialer func(ctx context.Context, network, addr string) (net.Conn, error)
OnConnect func(*Conn) error
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,
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,
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
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,
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
}