Class IdempotenceAwareRetryPolicy

A retry policy that avoids retrying non-idempotent statements.

In case of write timeouts this policy will always return Rethrow() if the statement is considered non-idempotent (see IsIdempotent). For all other cases, this policy delegates the decision to the child policy.

Inheritance

object

IdempotenceAwareRetryPolicy

Implements

IExtendedRetryPolicy

IRetryPolicy

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Cassandra

Assembly: Cassandra.dll

Syntax

public class IdempotenceAwareRetryPolicy : IExtendedRetryPolicy, IRetryPolicy

Constructors

IdempotenceAwareRetryPolicy(IRetryPolicy)

Creates a new instance of IdempotenceAwareRetryPolicy.

Declaration

public IdempotenceAwareRetryPolicy(IRetryPolicy childPolicy)

Parameters

Type	Name	Description
IRetryPolicy	childPolicy	The retry policy to wrap.

Properties

ChildPolicy

Declaration

public IRetryPolicy ChildPolicy { get; }

Property Value

Type	Description
IRetryPolicy

Methods

OnReadTimeout(IStatement, ConsistencyLevel, int, int, bool, int)

Defines whether to retry and at which consistency level on a read timeout.

Note that this method may be called even if requiredResponses >= receivedResponses if dataPresent is false (see com.datastax.driver.core.exceptions.ReadTimeoutException#WasDataRetrieved).

Declaration

public RetryDecision OnReadTimeout(IStatement stmt, ConsistencyLevel cl, int requiredResponses, int receivedResponses, bool dataRetrieved, int nbRetry)

Parameters

Type	Name	Description
IStatement	stmt
ConsistencyLevel	cl	the original consistency level of the read that timeouted.
int	requiredResponses	the number of responses that were required to achieve the requested consistency level.
int	receivedResponses	the number of responses that had been received by the time the timeout exception was raised.
bool	dataRetrieved	whether actual data (by opposition to data checksum) was present in the received responses.
int	nbRetry	the number of retry already performed for this operation.

Returns

Type	Description
RetryDecision	the retry decision. If RetryDecision.Rethrow is returned, a com.datastax.driver.core.exceptions.ReadTimeoutException will be thrown for the operation.

OnRequestError(IStatement, Configuration, Exception, int)

Defines whether to retry and at which consistency level on an unexpected error.

This method might be invoked in the following situations:

1. On a client timeout, while waiting for the server response (see ReadTimeoutMillis).
2. On a socket error (socket closed, etc.).
3. When the contacted host replies with an OVERLOADED error or a SERVER_ERROR.

Note that when such an error occurs, there is no guarantee that the mutation has been applied server-side or not.

Declaration

public RetryDecision OnRequestError(IStatement stmt, Configuration config, Exception ex, int nbRetry)

Parameters

Type	Name	Description
IStatement	stmt
Configuration	config	The current cluster configuration.
Exception	ex	The exception that caused this request to fail.
int	nbRetry	The number of retries already performed for this operation.

Returns

Type	Description
RetryDecision

OnUnavailable(IStatement, ConsistencyLevel, int, int, int)

Defines whether to retry and at which consistency level on an unavailable exception.

Declaration

public RetryDecision OnUnavailable(IStatement stmt, ConsistencyLevel cl, int requiredReplica, int aliveReplica, int nbRetry)

Parameters

Type	Name	Description
IStatement	stmt
ConsistencyLevel	cl	the original consistency level for the operation.
int	requiredReplica	the number of replica that should have been (known) alive for the operation to be attempted.
int	aliveReplica	the number of replica that were know to be alive by the coordinator of the operation.
int	nbRetry	the number of retry already performed for this operation.

Returns

Type	Description
RetryDecision	the retry decision. If RetryDecision.Rethrow is returned, an com.datastax.driver.core.exceptions.UnavailableException will be thrown for the operation.

OnWriteTimeout(IStatement, ConsistencyLevel, string, int, int, int)

Defines whether to retry and at which consistency level on a write timeout.

Declaration

public RetryDecision OnWriteTimeout(IStatement stmt, ConsistencyLevel cl, string writeType, int requiredAcks, int receivedAcks, int nbRetry)

Parameters

Type	Name	Description
IStatement	stmt
ConsistencyLevel	cl	the original consistency level of the write that timeouted.
string	writeType	the type of the write that timeouted.
int	requiredAcks	the number of acknowledgments that were required to achieve the requested consistency level.
int	receivedAcks	the number of acknowledgments that had been received by the time the timeout exception was raised.
int	nbRetry	the number of retry already performed for this operation.

Returns

Type	Description
RetryDecision	the retry decision. If RetryDecision.Rethrow is returned, a com.datastax.driver.core.exceptions.WriteTimeoutException will be thrown for the operation.

Implements

IExtendedRetryPolicy

IRetryPolicy