tcp

Documentation

Overview

Package tcp is the TCP_CHECK health check: connect to the backend, and treat a completed connection as healthy.

It is the simplest of the checker types and the one the others build on — HTTP, SMTP and DNS all begin with the same connection and then talk further.

Index

• type Checker
  • func New(opts layer4.Options, timeout time.Duration) Checker
  • func (c Checker) Check(ctx context.Context) (layer4.Result, error)

Types

type Checker

type Checker struct {
	Opts layer4.Options
}

Checker performs a TCP connection check.

func New

func New(opts layer4.Options, timeout time.Duration) Checker

New returns a checker for an address, with the given connect timeout.

func (Checker) Check

func (c Checker) Check(ctx context.Context) (layer4.Result, error)

Check performs one connection attempt.

The connection is closed immediately: TCP_CHECK asks only whether the backend will accept one. Holding it open would leave a connection per check per backend accumulating in the backend's table for no benefit.