Package oracle.nosql.driver

Interface RetryHandler

All Known Implementing Classes:

DefaultRetryHandler

public interface RetryHandler

RetryHandler is called by the request handling system when a RetryableException is thrown. It controls the number of retries as well as frequency of retries using a delaying algorithm. A default RetryHandler is always configured on a NoSQLHandle instance and can be controlled or overridden using NoSQLHandleConfig.setRetryHandler(oracle.nosql.driver.RetryHandler) and NoSQLHandleConfig.configureDefaultRetryHandler(int, int)

It is not recommended that applications rely on a RetryHandler for regulating provisioned throughput. It is best to add rate limiting to the application based on a table's capacity and access patterns to avoid throttling exceptions: see NoSQLHandleConfig.setRateLimitingEnabled(boolean).

Instances of this interface must be immutable so they can be shared among threads.

Method Summary

Modifier and Type	Method	Description
void	delay(Request request, int numRetries, RetryableException re)	This method is called when a RetryableException is thrown and it is determined that the request will be retried based on the return value of doRetry(oracle.nosql.driver.ops.Request, int, oracle.nosql.driver.RetryableException).
boolean	doRetry(Request request, int numRetries, RetryableException re)	This method is called when a RetryableException is thrown and determines whether to perform a retry or not based on the parameters.
int	getNumRetries()	Returns the number of retries that this handler instance will allow before the exception is thrown to the application.

Method Detail

getNumRetries

int getNumRetries()

Returns the number of retries that this handler instance will allow before the exception is thrown to the application.

Returns:

the max number of retries

doRetry

boolean doRetry(Request request,
                int numRetries,
                RetryableException re)

This method is called when a RetryableException is thrown and determines whether to perform a retry or not based on the parameters.

Parameters:

request - the Request that has triggered the exception

numRetries - the number of retries that have occurred for the operation

re - the exception that was thrown

Returns:

true if the operation should be retried, false if not, causing the exception to be thrown to the application.

delay

void delay(Request request,
           int numRetries,
           RetryableException re)

This method is called when a RetryableException is thrown and it is determined that the request will be retried based on the return value of doRetry(oracle.nosql.driver.ops.Request, int, oracle.nosql.driver.RetryableException). It provides a delay between retries. Most implementations will sleep for some period of time. The method should not return until the desired delay period has passed. Implementations should not busy-wait in a tight loop.

Parameters:

request - the Request that has triggered the exception

numRetries - the number of retries that have occurred for the operation

re - the exception that was thrown