2019-09-23 21:09:10 +03:00

125 lines
3.3 KiB
Go

package retry
import (
"time"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
)
// WithDefaultInterceptor returns interceptor that DOESN'T retry anything.
// Its possible to change its behaviour with call options.
func WithDefaultInterceptor() grpc.DialOption {
return grpc.WithUnaryInterceptor(Interceptor())
}
// WithMax option sets quantity of retry attempts.
// It handles negative maxRetryCount as INFINITE retries.
func WithMax(maxRetryCount int) grpc.CallOption {
return newOption(setRetryQuantity(maxRetryCount))
}
// WithCodes overrides the whole retriable codes list.
func WithCodes(codes ...codes.Code) grpc.CallOption {
return newOption(setRetriableCodes(codes...))
}
// WithAttemptHeader adds retry attempt number to context outgoing metadata, with key "x-retry-attempt".
func WithAttemptHeader(enable bool) grpc.CallOption {
return newOption(setAttemptHeader(enable))
}
// WithPerCallTimeout adds timeout for retry calls.
func WithPerCallTimeout(to time.Duration) grpc.CallOption {
return newOption(setPerCallTimeout(to))
}
// WithBackoff sets up interceptor with custom defined backoff function
func WithBackoff(f BackoffFunc) grpc.CallOption {
return newOption(setBackoff(f))
}
// DefaultBackoff uses exponential backoff with jitter, with base = 50ms, and maximum timeout = 1 minute.
func DefaultBackoff() BackoffFunc {
return DefaultExponentialJitterBackoff()
}
// WithDefaultExponentialJitterBackoff same as WithDefaultBackoff
func DefaultExponentialJitterBackoff() BackoffFunc {
return BackoffExponentialWithJitter(defaultExponentialBackoffBase, defaultExponentialBackoffCap)
}
// DefaultLinearJitterBackoff uses linear backoff with base = 50ms, and jitter = +-10%
func DefaultLinearJitterBackoff() BackoffFunc {
return BackoffLinearWithJitter(defaultLinearBackoffTimeout, defaultLinearBackoffJitter)
}
type options struct {
maxRetryCount int
retriableCodes []codes.Code
addCountToHeader bool
perCallTimeout time.Duration
backoffFunc BackoffFunc
}
var (
// TODO(seukyaso): Consider adding some non-zero default retry options
DefaultRetriableCodes = []codes.Code{codes.ResourceExhausted, codes.Unavailable}
defaultOptions = &options{
maxRetryCount: 0,
retriableCodes: DefaultRetriableCodes,
addCountToHeader: false,
perCallTimeout: 0,
backoffFunc: nil,
}
)
const (
defaultLinearBackoffTimeout = 50 * time.Millisecond
defaultLinearBackoffJitter = 0.1
defaultExponentialBackoffBase = 50 * time.Millisecond
defaultExponentialBackoffCap = 1 * time.Minute
)
type applyOptionFunc func(opt *options)
type interceptorOption struct {
grpc.EmptyCallOption
applyFunc applyOptionFunc
}
func newOption(f applyOptionFunc) grpc.CallOption {
return interceptorOption{applyFunc: f}
}
func setRetryQuantity(r int) applyOptionFunc {
return func(opt *options) {
opt.maxRetryCount = r
}
}
func setRetriableCodes(codes ...codes.Code) applyOptionFunc {
return func(opt *options) {
opt.retriableCodes = codes
}
}
func setAttemptHeader(enable bool) applyOptionFunc {
return func(opt *options) {
opt.addCountToHeader = enable
}
}
func setPerCallTimeout(to time.Duration) applyOptionFunc {
return func(opt *options) {
opt.perCallTimeout = to
}
}
func setBackoff(f BackoffFunc) applyOptionFunc {
return func(opt *options) {
opt.backoffFunc = f
}
}