Class RetrySettings

Settings for retrying RPCs.

Inheritance

System.Object

RetrySettings

Inherited Members

System.Object.ToString()

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

Namespace: Google.Api.Gax.Grpc

Assembly: Google.Api.Gax.Grpc.dll

Syntax

public sealed class RetrySettings

Properties

BackoffJitter

The delay jitter to apply for delays, defaulting to RandomJitter. This is never null.

Declaration

public RetrySettings.IJitter BackoffJitter { get; }

Property Value

Type	Description
RetrySettings.IJitter

Remarks

"Jitter" is used to introduce randomness into the pattern of delays. This is to avoid multiple clients performing the same delay pattern starting at the same point in time, leading to higher-than-necessary contention. The default jitter simply takes each maximum delay and returns an actual delay which is a uniformly random value between 0 and the maximum. This is good enough for most applications, but makes precise testing difficult.

BackoffMultiplier

The multiplier to apply to the backoff on each iteration; always greater than or equal to 1.0.

Declaration

public double BackoffMultiplier { get; }

Property Value

Type	Description
System.Double

Remarks

As an example, a multiplier of 2.0 with an initial backoff of 0.1s on an RPC would then apply a backoff of 0.2s, then 0.4s until it is capped by MaxBackoff.

InitialBackoff

The backoff time between the first attempt and the first retry. Always non-negative.

Declaration

public TimeSpan InitialBackoff { get; }

Property Value

Type	Description
System.TimeSpan

MaxAttempts

The maximum number of attempts to make. Always greater than or equal to 1.

Declaration

public int MaxAttempts { get; }

Property Value

Type	Description
System.Int32

MaxBackoff

The maximum backoff time between retries. Always non-negative.

Declaration

public TimeSpan MaxBackoff { get; }

Property Value

Type	Description
System.TimeSpan

NoJitter

A jitter which simply returns the specified maximum delay.

Declaration

public static RetrySettings.IJitter NoJitter { get; }

Property Value

Type	Description
RetrySettings.IJitter

RandomJitter

The default jitter which returns a uniformly distributed random delay between 0 and the specified maximum.

Declaration

public static RetrySettings.IJitter RandomJitter { get; }

Property Value

Type	Description
RetrySettings.IJitter

RetryFilter

A predicate to determine whether or not a particular exception should cause the operation to be retried. Usually this is simply a matter of checking the status codes. This is never null.

Declaration

public Predicate<Exception> RetryFilter { get; }

Property Value

Type	Description
System.Predicate<System.Exception>

Methods

FilterForStatusCodes(StatusCode[])

Creates a retry filter based on status codes.

Declaration

public static Predicate<Exception> FilterForStatusCodes(params StatusCode[] statusCodes)

Parameters

Type	Name	Description
StatusCode[]	statusCodes	The status codes to retry. Must not be null.

Returns

Type	Description
System.Predicate<System.Exception>	A retry filter based on status codes.

FilterForStatusCodes(IEnumerable<StatusCode>)

Creates a retry filter based on status codes.

Declaration

public static Predicate<Exception> FilterForStatusCodes(IEnumerable<StatusCode> statusCodes)

Parameters

Type	Name	Description
System.Collections.Generic.IEnumerable<StatusCode>	statusCodes	The status codes to retry. Must not be null.

Returns

Type	Description
System.Predicate<System.Exception>	A retry filter based on status codes.

FromConstantBackoff(Int32, TimeSpan, Predicate<Exception>, RetrySettings.IJitter)

Returns a RetrySettings using the specified maximum number of attempts and a constant backoff. Jitter is still applied to each backoff, but the "base" value of the backoff is always backoff.

Declaration

public static RetrySettings FromConstantBackoff(int maxAttempts, TimeSpan backoff, Predicate<Exception> retryFilter, RetrySettings.IJitter backoffJitter = null)

Parameters

Type	Name	Description
System.Int32	maxAttempts	The maximum number of attempts to make. Must be positive.
System.TimeSpan	backoff	The backoff after each failure. Must be non-negative.
System.Predicate<System.Exception>	retryFilter	The predicate to use to check whether an error should be retried. Must not be null.
RetrySettings.IJitter	backoffJitter	The jitter to use on each backoff. May be null, in which case RandomJitter is used.

Returns

Type	Description
RetrySettings	A retry with constant backoff.

FromExponentialBackoff(Int32, TimeSpan, TimeSpan, Double, Predicate<Exception>, RetrySettings.IJitter)

Returns a RetrySettings using the specified maximum number of attempts and an exponential backoff.

Declaration

public static RetrySettings FromExponentialBackoff(int maxAttempts, TimeSpan initialBackoff, TimeSpan maxBackoff, double backoffMultiplier, Predicate<Exception> retryFilter, RetrySettings.IJitter backoffJitter = null)

Parameters

Type	Name	Description
System.Int32	maxAttempts	The maximum number of attempts to make. Must be positive.
System.TimeSpan	initialBackoff	The backoff after the initial failure. Must be non-negative.
System.TimeSpan	maxBackoff	The maximum backoff. Must be at least initialBackoff.
System.Double	backoffMultiplier	The multiplier to apply to backoff times. Must be at least 1.0.
System.Predicate<System.Exception>	retryFilter	The predicate to use to check whether an error should be retried. Must not be null.
RetrySettings.IJitter	backoffJitter	The jitter to use on each backoff. May be null, in which case RandomJitter is used.

Returns

Type	Description
RetrySettings	A retry with exponential backoff.

NextBackoff(TimeSpan)

Works out the next backoff from the current one, based on the multiplier and maximum.

Declaration

public TimeSpan NextBackoff(TimeSpan currentBackoff)

Parameters

Type	Name	Description
System.TimeSpan	currentBackoff	The current backoff to use as a basis for the next one.

Returns

Type	Description
System.TimeSpan	The next backoff to use, which is always at least InitialBackoff and at most MaxBackoff.