package conn

import "github.com/go-kit/kit/util/conn"

Package conn provides utilities related to connections.

Index ¶

• Variables
• func Exponential(d time.Duration) time.Duration
• type AfterFunc
• type Dialer
• type Manager
• func NewDefaultManager(network, address string, logger log.Logger) *Manager
• func NewManager(d Dialer, network, address string, after AfterFunc, logger log.Logger) *Manager
• func (m *Manager) Put(err error)
• func (m *Manager) Take() net.Conn
• func (m *Manager) Write(b []byte) (int, error)

Package Files ¶

doc.go manager.go

Variables ¶

var ErrConnectionUnavailable = errors.New("connection unavailable")

ErrConnectionUnavailable is returned by the Manager's Write method when the manager cannot yield a good connection.

func Exponential ¶ Uses

func Exponential(d time.Duration) time.Duration

Exponential takes a duration and returns another one that is twice as long, +/- 50%. It is used to provide backoff for operations that may fail and should avoid thundering herds. See https://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/ for rationale

type AfterFunc ¶ Uses

type AfterFunc func(time.Duration) <-chan time.Time

AfterFunc imitates time.After.

type Dialer ¶ Uses

type Dialer func(network, address string) (net.Conn, error)

Dialer imitates net.Dial. Dialer is assumed to yield connections that are safe for use by multiple concurrent goroutines.

type Manager ¶ Uses

type Manager struct {
    // contains filtered or unexported fields
}

Manager manages a net.Conn.

Clients provide a way to create the connection with a Dialer, network, and address. Clients should Take the connection when they want to use it, and Put back whatever error they receive from its use. When a non-nil error is Put, the connection is invalidated, and a new connection is established. Connection failures are retried after an exponential backoff.

func NewDefaultManager ¶ Uses

func NewDefaultManager(network, address string, logger log.Logger) *Manager

NewDefaultManager is a helper constructor, suitable for most normal use in real (non-test) code. It uses the real net.Dial and time.After functions.

func NewManager ¶ Uses

func NewManager(d Dialer, network, address string, after AfterFunc, logger log.Logger) *Manager

NewManager returns a connection manager using the passed Dialer, network, and address. The AfterFunc is used to control exponential backoff and retries. The logger is used to log errors; pass a log.NopLogger if you don't care to receive them. For normal use, prefer NewDefaultManager.

func (*Manager) Put ¶ Uses

func (m *Manager) Put(err error)

Put accepts an error that came from a previously yielded connection. If the error is non-nil, the manager will invalidate the current connection and try to reconnect, with exponential backoff. Putting a nil error is a no-op.

func (*Manager) Take ¶ Uses

func (m *Manager) Take() net.Conn

Take yields the current connection. It may be nil.

func (*Manager) Write ¶ Uses

func (m *Manager) Write(b []byte) (int, error)

Write writes the passed data to the connection in a single Take/Put cycle.