Package org.apache.hadoop.io.retry

Class RetryPolicies.MultipleLinearRandomRetry

java.lang.Object

org.apache.hadoop.io.retry.RetryPolicies.MultipleLinearRandomRetry

All Implemented Interfaces:

RetryPolicy

Enclosing class:

RetryPolicies

public static class RetryPolicies.MultipleLinearRandomRetry
extends java.lang.Object
implements RetryPolicy

Given pairs of number of retries and sleep time (n0, t0), (n1, t1), ..., the first n0 retries sleep t0 milliseconds on average, the following n1 retries sleep t1 milliseconds on average, and so on. For all the sleep, the actual sleep time is randomly uniform distributed in the close interval [0.5t, 1.5t], where t is the sleep time specified. The objects of this class are immutable.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	RetryPolicies.MultipleLinearRandomRetry.Pair	Pairs of numRetries and sleepSeconds

Nested classes/interfaces inherited from interface org.apache.hadoop.io.retry.RetryPolicy

RetryPolicy.RetryAction

Constructor Summary

Constructors

Constructor	Description
MultipleLinearRandomRetry(java.util.List<RetryPolicies.MultipleLinearRandomRetry.Pair> pairs)

Method Summary

Modifier and Type	Method	Description
boolean	equals(java.lang.Object that)
int	hashCode()
static RetryPolicies.MultipleLinearRandomRetry	parseCommaSeparatedString(java.lang.String s)	Parse the given string as a MultipleLinearRandomRetry object.
RetryPolicy.RetryAction	shouldRetry(java.lang.Exception e, int curRetry, int failovers, boolean isIdempotentOrAtMostOnce)	Determines whether the framework should retry a method for the given exception, and the number of retries that have been made for that operation so far.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

MultipleLinearRandomRetry

public MultipleLinearRandomRetry(java.util.List<RetryPolicies.MultipleLinearRandomRetry.Pair> pairs)

Method Detail

shouldRetry

public RetryPolicy.RetryAction shouldRetry(java.lang.Exception e,
                                           int curRetry,
                                           int failovers,
                                           boolean isIdempotentOrAtMostOnce)
                                    throws java.lang.Exception

Description copied from interface: RetryPolicy

Determines whether the framework should retry a method for the given exception, and the number of retries that have been made for that operation so far.

Specified by:

shouldRetry in interface RetryPolicy

Parameters:

e - The exception that caused the method to fail

curRetry - The number of times the method has been retried

failovers - The number of times the method has failed over to a different backend implementation

isIdempotentOrAtMostOnce - true if the method is Idempotent or AtMostOnce and so can reasonably be retried on failover when we don't know if the previous attempt reached the server or not

Returns:

RetryPolicy.RetryAction with RetryDecision.FAIL if the method should not be retried, RetryDecision.RETRY if the method should be retried or RetryDecision.FAILOVER_AND_RETRY if failover has to be performed before retry.

Throws:

java.lang.Exception - The re-thrown exception e indicating that the method failed and should not be retried further

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object that)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

parseCommaSeparatedString

public static RetryPolicies.MultipleLinearRandomRetry parseCommaSeparatedString(java.lang.String s)

Parse the given string as a MultipleLinearRandomRetry object. The format of the string is "t_1, n_1, t_2, n_2, ...", where t_i and n_i are the i-th pair of sleep time and number of retries. Note that the white spaces in the string are ignored.

Parameters:

s - input string.

Returns:

the parsed object, or null if the parsing fails.