breaker

Documentation

Index

• Variables
• func IsErrorPermanent(err error) bool
• type CircuitBreaker
  • func (c *CircuitBreaker) Execute(oper func() (any, error)) (any, error)
  • func (c *CircuitBreaker) Initialize(log logger.Logger)
  • func (c *CircuitBreaker) State() CircuitBreakerState
  • func (c *CircuitBreaker) String() string
• type CircuitBreakerState

Variables

var (
	ErrOpenState       = gobreaker.ErrOpenState
	ErrTooManyRequests = gobreaker.ErrTooManyRequests
)

Functions

func IsErrorPermanent

func IsErrorPermanent(err error) bool

IsErrorPermanent returns true if `err` should be treated as a permanent error that cannot be retried.

Types

type CircuitBreaker

type CircuitBreaker struct {
	// Name is the circuit breaker name.
	Name string
	// The maximum number of requests allowed to pass through when
	// the circuit breaker is half-open.
	// Default is 1.
	MaxRequests uint32 `mapstructure:"maxRequests"`
	// The cyclic period of the closed state for the circuit breaker
	// to clear the internal counts. If 0, the circuit breaker doesn't
	// clear internal counts during the closed state.
	// Default is 0s.
	Interval time.Duration `mapstructure:"interval"`
	// The period of the open state, after which the state of the
	// circuit breaker becomes half-open.
	// Default is 60s.
	Timeout time.Duration `mapstructure:"timeout"`
	// Trip is a CEL expression evaluated with the circuit breaker's
	// internal counts whenever a request fails in the closed state.
	// If it evaluates to true, the circuit breaker will be placed
	// into the open state.
	// Default is consecutiveFailures > 5.
	Trip *expr.Expr `mapstructure:"trip"`
	// contains filtered or unexported fields
}

CircuitBreaker represents the configuration for how a circuit breaker behaves.

func (*CircuitBreaker) Execute

func (c *CircuitBreaker) Execute(oper func() (any, error)) (any, error)

Execute invokes `oper` if the circuit breaker is in a closed state or for an allowed call in the half-open state. It is a wrapper around the gobreaker library that is used here. The circuit breaker shorts if the connection is in open state or if there are too many requests in the half-open state. In both cases, the error returned is wrapped with ErrOpenState or ErrTooManyRequests defined in this package. The result of the operation in those scenarios will by nil/zero. In all other scenarios the result, error returned is the result, error returned by the operation.

func (*CircuitBreaker) Initialize

func (c *CircuitBreaker) Initialize(log logger.Logger)

Initialize creates the underlying circuit breaker using the configuration fields.

func (*CircuitBreaker) State

func (c *CircuitBreaker) State() CircuitBreakerState

State returns the current state of the circuit breaker.

func (*CircuitBreaker) String

func (c *CircuitBreaker) String() string

String implements fmt.Stringer and is used for debugging.

type CircuitBreakerState

type CircuitBreakerState string

const (
	StateClosed   CircuitBreakerState = "closed"
	StateOpen     CircuitBreakerState = "open"
	StateHalfOpen CircuitBreakerState = "half-open"
	StateUnknown  CircuitBreakerState = "unknown"
)