redis

Documentation

Index

• Variables
• func MustRegisterClientMetricsCollector(client poolStatGetter, stats prometheus.Registerer, addrs map[string]string, ...)
• type Config
• type Ring
  • func NewRingFromConfig(c Config, stats prometheus.Registerer, log blog.Logger) (*Ring, error)
  • func (r *Ring) StopLookups()

Variables

var ErrNoShardsResolved = errors.New("0 shards were resolved")

Functions

func MustRegisterClientMetricsCollector

func MustRegisterClientMetricsCollector(client poolStatGetter, stats prometheus.Registerer, addrs map[string]string, user string)

MustRegisterClientMetricsCollector registers a metrics collector for the given Redis client with the provided prometheus.Registerer. The collector will report metrics labelled by the provided addresses and username. If the collector is already registered, this function is a no-op.

Types

type Config

type Config struct {
	// TLS contains the configuration to speak TLS with Redis.
	TLS cmd.TLSConfig

	// Username used to authenticate to each Redis instance.
	Username string `validate:"required"`

	// PasswordFile is the path to a file holding the password used to
	// authenticate to each Redis instance.
	cmd.PasswordConfig

	// ShardAddrs is a map of shard names to IP address:port pairs. The go-redis
	// `Ring` client will shard reads and writes across the provided Redis
	// Servers based on a consistent hashing algorithm.
	ShardAddrs map[string]string `validate:"omitempty,required_without=Lookups,min=1,dive,hostname_port"`

	// Lookups each entry contains a service and domain name that will be used
	// to construct a SRV DNS query to lookup Redis backends. For example: if
	// the resource record is 'foo.service.consul', then the 'Service' is 'foo'
	// and the 'Domain' is 'service.consul'. The expected dNSName to be
	// authenticated in the server certificate would be 'foo.service.consul'.
	Lookups []cmd.ServiceDomain `validate:"omitempty,required_without=ShardAddrs,min=1,dive"`

	// LookupFrequency is the frequency of periodic SRV lookups. Defaults to 30
	// seconds.
	LookupFrequency config.Duration `validate:"-"`

	// LookupDNSAuthority can only be specified with Lookups. It's a single
	// <hostname|IPv4|[IPv6]>:<port> of the DNS server to be used for resolution
	// of Redis backends. If the address contains a hostname it will be resolved
	// using system DNS. If the address contains a port, the client will use it
	// directly, otherwise port 53 is used. If this field is left unspecified
	// the system DNS will be used for resolution.
	LookupDNSAuthority string `validate:"excluded_without=Lookups,omitempty,ip|hostname|hostname_port"`

	// Enables read-only commands on replicas.
	ReadOnly bool
	// Allows routing read-only commands to the closest primary or replica.
	// It automatically enables ReadOnly.
	RouteByLatency bool
	// Allows routing read-only commands to a random primary or replica.
	// It automatically enables ReadOnly.
	RouteRandomly bool

	// PoolFIFO uses FIFO mode for each node connection pool GET/PUT (default LIFO).
	PoolFIFO bool

	// Maximum number of retries before giving up.
	// Default is to not retry failed commands.
	MaxRetries int `validate:"min=0"`
	// Minimum backoff between each retry.
	// Default is 8 milliseconds; -1 disables backoff.
	MinRetryBackoff config.Duration `validate:"-"`
	// Maximum backoff between each retry.
	// Default is 512 milliseconds; -1 disables backoff.
	MaxRetryBackoff config.Duration `validate:"-"`

	// Dial timeout for establishing new connections.
	// Default is 5 seconds.
	DialTimeout config.Duration `validate:"-"`
	// Timeout for socket reads. If reached, commands will fail
	// with a timeout instead of blocking. Use value -1 for no timeout and 0 for default.
	// Default is 3 seconds.
	ReadTimeout config.Duration `validate:"-"`
	// Timeout for socket writes. If reached, commands will fail
	// with a timeout instead of blocking.
	// Default is ReadTimeout.
	WriteTimeout config.Duration `validate:"-"`

	// Maximum number of socket connections.
	// Default is 5 connections per every CPU as reported by runtime.NumCPU.
	// If this is set to an explicit value, that's not multiplied by NumCPU.
	// PoolSize applies per cluster node and not for the whole cluster.
	// https://pkg.go.dev/github.com/go-redis/redis#ClusterOptions
	PoolSize int `validate:"min=0"`
	// Minimum number of idle connections which is useful when establishing
	// new connection is slow.
	MinIdleConns int `validate:"min=0"`
	// Connection age at which client retires (closes) the connection.
	// Default is to not close aged connections.
	MaxConnAge config.Duration `validate:"-"`
	// Amount of time client waits for connection if all connections
	// are busy before returning an error.
	// Default is ReadTimeout + 1 second.
	PoolTimeout config.Duration `validate:"-"`
	// Amount of time after which client closes idle connections.
	// Should be less than server's timeout.
	// Default is 5 minutes. -1 disables idle timeout check.
	IdleTimeout config.Duration `validate:"-"`
	// Frequency of idle checks made by idle connections reaper.
	// Default is 1 minute. -1 disables idle connections reaper,
	// but idle connections are still discarded by the client
	// if IdleTimeout is set.
	// Deprecated: This field has been deprecated and will be removed.
	IdleCheckFrequency config.Duration `validate:"-"`
}

Config contains the configuration needed to act as a Redis client.

type Ring

type Ring struct {
	*redis.Ring
	// contains filtered or unexported fields
}

Ring is a wrapper around the go-redis/v9 Ring client that adds support for (optional) periodic SRV lookups.

func NewRingFromConfig

func NewRingFromConfig(c Config, stats prometheus.Registerer, log blog.Logger) (*Ring, error)

NewRingFromConfig returns a new *redis.Ring client. If periodic SRV lookups are supplied, a goroutine will be started to periodically perform lookups. Callers should defer a call to StopLookups() to ensure that this goroutine is gracefully shutdown.

func (*Ring) StopLookups

func (r *Ring) StopLookups()

StopLookups stops the goroutine responsible for keeping the shards of the inner *redis.Ring up-to-date. It is a no-op if the Ring was not constructed with periodic lookups or if the lookups have already been stopped.