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 Details

    • 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