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README
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go-sentinel
Redis Sentinel support for redigo library.
Documentation
Alternative solution
You can alternatively configure Haproxy between your application and Redis to proxy requests to Redis master instance if you only need HA:
listen redis
server redis-01 127.0.0.1:6380 check port 6380 check inter 2s weight 1 inter 2s downinter 5s rise 10 fall 2 on-marked-down shutdown-sessions on-marked-up shutdown-backup-sessions
server redis-02 127.0.0.1:6381 check port 6381 check inter 2s weight 1 inter 2s downinter 5s rise 10 fall 2 backup
bind *:6379
mode tcp
option tcpka
option tcplog
option tcp-check
tcp-check send PING\r\n
tcp-check expect string +PONG
tcp-check send info\ replication\r\n
tcp-check expect string role:master
tcp-check send QUIT\r\n
tcp-check expect string +OK
balance roundrobin
This way you don't need to use this library.
License
Library is available under the Apache License, Version 2.0.
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func TestRole ¶
TestRole wraps GetRole in a test to verify if the role matches an expected role string. If there was any error in querying the supplied connection, the function returns false. Works with Redis >= 2.8.12. It's not goroutine safe, but if you call this method on pooled connections then you are OK.
Types ¶
type NoSentinelsAvailable ¶
type NoSentinelsAvailable struct {
// contains filtered or unexported fields
}
NoSentinelsAvailable is returned when all sentinels in the list are exhausted (or none configured), and contains the last error returned by Dial (which may be nil)
func (NoSentinelsAvailable) Error ¶
func (ns NoSentinelsAvailable) Error() string
type Sentinel ¶
type Sentinel struct {
// Addrs is a slice with known Sentinel addresses.
Addrs []string
// MasterName is a name of Redis master Sentinel servers monitor.
MasterName string
// Dial is a user supplied function to connect to Sentinel on given address. This
// address will be chosen from Addrs slice.
// Note that as per the redis-sentinel client guidelines, a timeout is mandatory
// while connecting to Sentinels, and should not be set to 0.
Dial func(addr string) (redis.Conn, error)
// Pool is a user supplied function returning custom connection pool to Sentinel.
// This can be useful to tune options if you are not satisfied with what default
// Sentinel pool offers. See defaultPool() method for default pool implementation.
// In most cases you only need to provide Dial function and let this be nil.
Pool func(addr string) *redis.Pool
// contains filtered or unexported fields
}
Sentinel provides a way to add high availability (HA) to Redis Pool using preconfigured addresses of Sentinel servers and name of master which Sentinels monitor. It works with Redis >= 2.8.12 (mostly because of ROLE command that was introduced in that version, it's possible though to support old versions using INFO command).
Example of the simplest usage to contact master "mymaster":
func newSentinelPool() *redis.Pool {
sntnl := &sentinel.Sentinel{
Addrs: []string{":26379", ":26380", ":26381"},
MasterName: "mymaster",
Dial: func(addr string) (redis.Conn, error) {
timeout := 500 * time.Millisecond
c, err := redis.DialTimeout("tcp", addr, timeout, timeout, timeout)
if err != nil {
return nil, err
}
return c, nil
},
}
return &redis.Pool{
MaxIdle: 3,
MaxActive: 64,
Wait: true,
IdleTimeout: 240 * time.Second,
Dial: func() (redis.Conn, error) {
masterAddr, err := sntnl.MasterAddr()
if err != nil {
return nil, err
}
c, err := redis.Dial("tcp", masterAddr)
if err != nil {
return nil, err
}
return c, nil
},
TestOnBorrow: func(c redis.Conn, t time.Time) error {
if !sentinel.TestRole(c, "master") {
return errors.New("Role check failed")
} else {
return nil
}
},
}
}
func (*Sentinel) Discover ¶
Discover allows to update list of known Sentinel addresses. From docs:
A client may update its internal list of Sentinel nodes following this procedure: 1) Obtain a list of other Sentinels for this master using the command SENTINEL sentinels <master-name>. 2) Add every ip:port pair not already existing in our list at the end of the list.
func (*Sentinel) MasterAddr ¶
MasterAddr returns an address of current Redis master instance.
func (*Sentinel) SentinelAddrs ¶
SentinelAddrs returns a slice of known Sentinel addresses Sentinel server aware of.
func (*Sentinel) SlaveAddrs ¶
SlaveAddrs returns a slice with known slave addresses of current master instance.
Source Files