diff options
Diffstat (limited to 'vendor/google.golang.org/grpc/service_config.go')
| -rw-r--r-- | vendor/google.golang.org/grpc/service_config.go | 149 |
1 files changed, 137 insertions, 12 deletions
diff --git a/vendor/google.golang.org/grpc/service_config.go b/vendor/google.golang.org/grpc/service_config.go index 015631d..e0d7352 100644 --- a/vendor/google.golang.org/grpc/service_config.go +++ b/vendor/google.golang.org/grpc/service_config.go @@ -25,6 +25,7 @@ import ( "strings" "time" + "google.golang.org/grpc/codes" "google.golang.org/grpc/grpclog" ) @@ -56,6 +57,8 @@ type MethodConfig struct { // MaxRespSize is the maximum allowed payload size for an individual response in a // stream (server->client) in bytes. MaxRespSize *int + // RetryPolicy configures retry options for the method. + retryPolicy *retryPolicy } // ServiceConfig is provided by the service provider and contains parameters for how @@ -68,13 +71,84 @@ type ServiceConfig struct { // LB is the load balancer the service providers recommends. The balancer specified // via grpc.WithBalancer will override this. LB *string - // Methods contains a map for the methods in this service. - // If there is an exact match for a method (i.e. /service/method) in the map, use the corresponding MethodConfig. - // If there's no exact match, look for the default config for the service (/service/) and use the corresponding MethodConfig if it exists. - // Otherwise, the method has no MethodConfig to use. + + // Methods contains a map for the methods in this service. If there is an + // exact match for a method (i.e. /service/method) in the map, use the + // corresponding MethodConfig. If there's no exact match, look for the + // default config for the service (/service/) and use the corresponding + // MethodConfig if it exists. Otherwise, the method has no MethodConfig to + // use. Methods map[string]MethodConfig - stickinessMetadataKey *string + // If a retryThrottlingPolicy is provided, gRPC will automatically throttle + // retry attempts and hedged RPCs when the client’s ratio of failures to + // successes exceeds a threshold. + // + // For each server name, the gRPC client will maintain a token_count which is + // initially set to maxTokens, and can take values between 0 and maxTokens. + // + // Every outgoing RPC (regardless of service or method invoked) will change + // token_count as follows: + // + // - Every failed RPC will decrement the token_count by 1. + // - Every successful RPC will increment the token_count by tokenRatio. + // + // If token_count is less than or equal to maxTokens / 2, then RPCs will not + // be retried and hedged RPCs will not be sent. + retryThrottling *retryThrottlingPolicy +} + +// retryPolicy defines the go-native version of the retry policy defined by the +// service config here: +// https://github.com/grpc/proposal/blob/master/A6-client-retries.md#integration-with-service-config +type retryPolicy struct { + // MaxAttempts is the maximum number of attempts, including the original RPC. + // + // This field is required and must be two or greater. + maxAttempts int + + // Exponential backoff parameters. The initial retry attempt will occur at + // random(0, initialBackoffMS). In general, the nth attempt will occur at + // random(0, + // min(initialBackoffMS*backoffMultiplier**(n-1), maxBackoffMS)). + // + // These fields are required and must be greater than zero. + initialBackoff time.Duration + maxBackoff time.Duration + backoffMultiplier float64 + + // The set of status codes which may be retried. + // + // Status codes are specified as strings, e.g., "UNAVAILABLE". + // + // This field is required and must be non-empty. + // Note: a set is used to store this for easy lookup. + retryableStatusCodes map[codes.Code]bool +} + +type jsonRetryPolicy struct { + MaxAttempts int + InitialBackoff string + MaxBackoff string + BackoffMultiplier float64 + RetryableStatusCodes []codes.Code +} + +// retryThrottlingPolicy defines the go-native version of the retry throttling +// policy defined by the service config here: +// https://github.com/grpc/proposal/blob/master/A6-client-retries.md#integration-with-service-config +type retryThrottlingPolicy struct { + // The number of tokens starts at maxTokens. The token_count will always be + // between 0 and maxTokens. + // + // This field is required and must be greater than zero. + MaxTokens float64 + // The amount of tokens to add on each successful RPC. Typically this will + // be some number between 0 and 1, e.g., 0.1. + // + // This field is required and must be greater than zero. Up to 3 decimal + // places are supported. + TokenRatio float64 } func parseDuration(s *string) (*time.Duration, error) { @@ -144,13 +218,14 @@ type jsonMC struct { Timeout *string MaxRequestMessageBytes *int64 MaxResponseMessageBytes *int64 + RetryPolicy *jsonRetryPolicy } // TODO(lyuxuan): delete this struct after cleaning up old service config implementation. type jsonSC struct { - LoadBalancingPolicy *string - StickinessMetadataKey *string - MethodConfig *[]jsonMC + LoadBalancingPolicy *string + MethodConfig *[]jsonMC + RetryThrottling *retryThrottlingPolicy } func parseServiceConfig(js string) (ServiceConfig, error) { @@ -161,10 +236,9 @@ func parseServiceConfig(js string) (ServiceConfig, error) { return ServiceConfig{}, err } sc := ServiceConfig{ - LB: rsc.LoadBalancingPolicy, - Methods: make(map[string]MethodConfig), - - stickinessMetadataKey: rsc.StickinessMetadataKey, + LB: rsc.LoadBalancingPolicy, + Methods: make(map[string]MethodConfig), + retryThrottling: rsc.RetryThrottling, } if rsc.MethodConfig == nil { return sc, nil @@ -184,6 +258,10 @@ func parseServiceConfig(js string) (ServiceConfig, error) { WaitForReady: m.WaitForReady, Timeout: d, } + if mc.retryPolicy, err = convertRetryPolicy(m.RetryPolicy); err != nil { + grpclog.Warningf("grpc: parseServiceConfig error unmarshaling %s due to %v", js, err) + return ServiceConfig{}, err + } if m.MaxRequestMessageBytes != nil { if *m.MaxRequestMessageBytes > int64(maxInt) { mc.MaxReqSize = newInt(maxInt) @@ -205,9 +283,56 @@ func parseServiceConfig(js string) (ServiceConfig, error) { } } + if sc.retryThrottling != nil { + if sc.retryThrottling.MaxTokens <= 0 || + sc.retryThrottling.MaxTokens >= 1000 || + sc.retryThrottling.TokenRatio <= 0 { + // Illegal throttling config; disable throttling. + sc.retryThrottling = nil + } + } return sc, nil } +func convertRetryPolicy(jrp *jsonRetryPolicy) (p *retryPolicy, err error) { + if jrp == nil { + return nil, nil + } + ib, err := parseDuration(&jrp.InitialBackoff) + if err != nil { + return nil, err + } + mb, err := parseDuration(&jrp.MaxBackoff) + if err != nil { + return nil, err + } + + if jrp.MaxAttempts <= 1 || + *ib <= 0 || + *mb <= 0 || + jrp.BackoffMultiplier <= 0 || + len(jrp.RetryableStatusCodes) == 0 { + grpclog.Warningf("grpc: ignoring retry policy %v due to illegal configuration", jrp) + return nil, nil + } + + rp := &retryPolicy{ + maxAttempts: jrp.MaxAttempts, + initialBackoff: *ib, + maxBackoff: *mb, + backoffMultiplier: jrp.BackoffMultiplier, + retryableStatusCodes: make(map[codes.Code]bool), + } + if rp.maxAttempts > 5 { + // TODO(retry): Make the max maxAttempts configurable. + rp.maxAttempts = 5 + } + for _, code := range jrp.RetryableStatusCodes { + rp.retryableStatusCodes[code] = true + } + return rp, nil +} + func min(a, b *int) *int { if *a < *b { return a |