Class ExponentialBackOffPolicy
- java.lang.Object
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- com.google.api.client.http.ExponentialBackOffPolicy
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- All Implemented Interfaces:
BackOffPolicy
@Beta @Deprecated public class ExponentialBackOffPolicy extends Object implements BackOffPolicy
Deprecated.(scheduled to be removed in 1.18). UseHttpBackOffUnsuccessfulResponseHandler
withExponentialBackOff
instead.Beta
Implementation ofBackOffPolicy
that increases the back off period for each retry attempt using a randomization function that grows exponentially.getNextBackOffMillis()
is calculated using the following formula:randomized_interval = retry_interval * (random value in range [1 - randomization_factor, 1 + randomization_factor])
In other wordsgetNextBackOffMillis()
will range between the randomization factor percentage below and above the retry interval. For example, using 2 seconds as the base retry interval and 0.5 as the randomization factor, the actual back off period used in the next retry attempt will be between 1 and 3 seconds.Note: max_interval caps the retry_interval and not the randomized_interval.
If the time elapsed since an
ExponentialBackOffPolicy
instance is created goes past the max_elapsed_time then the methodgetNextBackOffMillis()
starts returningBackOffPolicy.STOP
. The elapsed time can be reset by callingreset()
.Example: The default retry_interval is .5 seconds, default randomization_factor is 0.5, default multiplier is 1.5 and the default max_interval is 1 minute. For 10 requests the sequence will be (values in seconds) and assuming we go over the max_elapsed_time on the 10th request:
request# retry_interval randomized_interval 1 0.5 [0.25, 0.75] 2 0.75 [0.375, 1.125] 3 1.125 [0.562, 1.687] 4 1.687 [0.8435, 2.53] 5 2.53 [1.265, 3.795] 6 3.795 [1.897, 5.692] 7 5.692 [2.846, 8.538] 8 8.538 [4.269, 12.807] 9 12.807 [6.403, 19.210] 10 19.210
BackOffPolicy.STOP
Implementation is not thread-safe.
- Since:
- 1.7
- Author:
- Ravi Mistry
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ExponentialBackOffPolicy.Builder
Deprecated.
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Field Summary
Fields Modifier and Type Field Description static int
DEFAULT_INITIAL_INTERVAL_MILLIS
Deprecated.The default initial interval value in milliseconds (0.5 seconds).static int
DEFAULT_MAX_ELAPSED_TIME_MILLIS
Deprecated.The default maximum elapsed time in milliseconds (15 minutes).static int
DEFAULT_MAX_INTERVAL_MILLIS
Deprecated.The default maximum back off time in milliseconds (1 minute).static double
DEFAULT_MULTIPLIER
Deprecated.The default multiplier value (1.5 which is 50% increase per back off).static double
DEFAULT_RANDOMIZATION_FACTOR
Deprecated.The default randomization factor (0.5 which results in a random period ranging between 50% below and 50% above the retry interval).-
Fields inherited from interface com.google.api.client.http.BackOffPolicy
STOP
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Constructor Summary
Constructors Modifier Constructor Description ExponentialBackOffPolicy()
Deprecated.Creates an instance of ExponentialBackOffPolicy using default values.protected
ExponentialBackOffPolicy(ExponentialBackOffPolicy.Builder builder)
Deprecated.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description static ExponentialBackOffPolicy.Builder
builder()
Deprecated.Returns an instance of a new builder.int
getCurrentIntervalMillis()
Deprecated.Returns the current retry interval in milliseconds.long
getElapsedTimeMillis()
Deprecated.Returns the elapsed time in milliseconds since anExponentialBackOffPolicy
instance is created and is reset whenreset()
is called.int
getInitialIntervalMillis()
Deprecated.Returns the initial retry interval in milliseconds.int
getMaxElapsedTimeMillis()
Deprecated.Returns the maximum elapsed time in milliseconds.int
getMaxIntervalMillis()
Deprecated.Returns the maximum value of the back off period in milliseconds.double
getMultiplier()
Deprecated.Returns the value to multiply the current interval with for each retry attempt.long
getNextBackOffMillis()
Deprecated.Gets the number of milliseconds to wait before retrying an HTTP request.double
getRandomizationFactor()
Deprecated.Returns the randomization factor to use for creating a range around the retry interval.boolean
isBackOffRequired(int statusCode)
Deprecated.Determines if back off is required based on the specified status code.void
reset()
Deprecated.Sets the interval back to the initial retry interval and restarts the timer.
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Field Detail
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DEFAULT_INITIAL_INTERVAL_MILLIS
public static final int DEFAULT_INITIAL_INTERVAL_MILLIS
Deprecated.The default initial interval value in milliseconds (0.5 seconds).- See Also:
- Constant Field Values
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DEFAULT_RANDOMIZATION_FACTOR
public static final double DEFAULT_RANDOMIZATION_FACTOR
Deprecated.The default randomization factor (0.5 which results in a random period ranging between 50% below and 50% above the retry interval).- See Also:
- Constant Field Values
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DEFAULT_MULTIPLIER
public static final double DEFAULT_MULTIPLIER
Deprecated.The default multiplier value (1.5 which is 50% increase per back off).- See Also:
- Constant Field Values
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DEFAULT_MAX_INTERVAL_MILLIS
public static final int DEFAULT_MAX_INTERVAL_MILLIS
Deprecated.The default maximum back off time in milliseconds (1 minute).- See Also:
- Constant Field Values
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DEFAULT_MAX_ELAPSED_TIME_MILLIS
public static final int DEFAULT_MAX_ELAPSED_TIME_MILLIS
Deprecated.The default maximum elapsed time in milliseconds (15 minutes).- See Also:
- Constant Field Values
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Constructor Detail
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ExponentialBackOffPolicy
public ExponentialBackOffPolicy()
Deprecated.Creates an instance of ExponentialBackOffPolicy using default values. To override the defaults usebuilder()
.initialIntervalMillis
is defaulted toDEFAULT_INITIAL_INTERVAL_MILLIS
randomizationFactor
is defaulted toDEFAULT_RANDOMIZATION_FACTOR
multiplier
is defaulted toDEFAULT_MULTIPLIER
maxIntervalMillis
is defaulted toDEFAULT_MAX_INTERVAL_MILLIS
maxElapsedTimeMillis
is defaulted inDEFAULT_MAX_ELAPSED_TIME_MILLIS
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ExponentialBackOffPolicy
protected ExponentialBackOffPolicy(ExponentialBackOffPolicy.Builder builder)
Deprecated.- Parameters:
builder
- builder- Since:
- 1.14
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Method Detail
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isBackOffRequired
public boolean isBackOffRequired(int statusCode)
Deprecated.Determines if back off is required based on the specified status code.The idea is that the servers are only temporarily unavailable, and they should not be overwhelmed when they are trying to get back up.
The default implementation requires back off for 500 and 503 status codes. Subclasses may override if different status codes are required.
- Specified by:
isBackOffRequired
in interfaceBackOffPolicy
- Parameters:
statusCode
- HTTP status code
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reset
public final void reset()
Deprecated.Sets the interval back to the initial retry interval and restarts the timer.- Specified by:
reset
in interfaceBackOffPolicy
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getNextBackOffMillis
public long getNextBackOffMillis() throws IOException
Deprecated.Gets the number of milliseconds to wait before retrying an HTTP request. IfBackOffPolicy.STOP
is returned, no retries should be made.This method calculates the next back off interval using the formula: randomized_interval = retry_interval +/- (randomization_factor * retry_interval)
Subclasses may override if a different algorithm is required.
- Specified by:
getNextBackOffMillis
in interfaceBackOffPolicy
- Returns:
- the number of milliseconds to wait when backing off requests, or
BackOffPolicy.STOP
if no more retries should be made - Throws:
IOException
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getInitialIntervalMillis
public final int getInitialIntervalMillis()
Deprecated.Returns the initial retry interval in milliseconds.
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getRandomizationFactor
public final double getRandomizationFactor()
Deprecated.Returns the randomization factor to use for creating a range around the retry interval.A randomization factor of 0.5 results in a random period ranging between 50% below and 50% above the retry interval.
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getCurrentIntervalMillis
public final int getCurrentIntervalMillis()
Deprecated.Returns the current retry interval in milliseconds.
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getMultiplier
public final double getMultiplier()
Deprecated.Returns the value to multiply the current interval with for each retry attempt.
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getMaxIntervalMillis
public final int getMaxIntervalMillis()
Deprecated.Returns the maximum value of the back off period in milliseconds. Once the current interval reaches this value it stops increasing.
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getMaxElapsedTimeMillis
public final int getMaxElapsedTimeMillis()
Deprecated.Returns the maximum elapsed time in milliseconds.If the time elapsed since an
ExponentialBackOffPolicy
instance is created goes past the max_elapsed_time then the methodgetNextBackOffMillis()
starts returningBackOffPolicy.STOP
. The elapsed time can be reset by callingreset()
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getElapsedTimeMillis
public final long getElapsedTimeMillis()
Deprecated.Returns the elapsed time in milliseconds since anExponentialBackOffPolicy
instance is created and is reset whenreset()
is called.The elapsed time is computed using
System.nanoTime()
.
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builder
public static ExponentialBackOffPolicy.Builder builder()
Deprecated.Returns an instance of a new builder.
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