https://github.com/datastax/java-driver/java-driver-core: A driver for Apache Cassandra(R) 2.1+ that works exclusively with the Cassandra Query Language version 3 (CQL3) and Cassandra's native protocol versions 3 and above.
  • Various (DataStax) 
/*
 * Copyright DataStax, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.datastax.oss.driver.api.core.session.throttling;

import com.datastax.oss.driver.api.core.RequestThrottlingException;
import edu.umd.cs.findbugs.annotations.NonNull;


A request that may be subjected to throttling by a RequestThrottler. 
/**
 * A request that may be subjected to throttling by a {@link
 * com.datastax.oss.driver.api.core.session.throttling.RequestThrottler}.
 */
public interface Throttled {

  
Invoked by the throttler to indicate that the request can now start. The request must wait for
this call until it does any "actual" work (typically, writing to a connection).

Params:
  • wasDelayed – indicates whether the throttler delayed at all; this is so that requests
    don't have to rely on measuring time to determine it (this is useful for metrics).
/**
   * Invoked by the throttler to indicate that the request can now start. The request must wait for
   * this call until it does any "actual" work (typically, writing to a connection).
   *
   * @param wasDelayed indicates whether the throttler delayed at all; this is so that requests
   *     don't have to rely on measuring time to determine it (this is useful for metrics).
   */
  void onThrottleReady(boolean wasDelayed);

  
Invoked by the throttler to indicate that the request cannot be fulfilled. Typically, this
means we've reached maximum capacity, and the request can't even be enqueued. This error must
be rethrown to the client.

Params:
  • error – the error that the request should be completed (exceptionally) with.
/**
   * Invoked by the throttler to indicate that the request cannot be fulfilled. Typically, this
   * means we've reached maximum capacity, and the request can't even be enqueued. This error must
   * be rethrown to the client.
   *
   * @param error the error that the request should be completed (exceptionally) with.
   */
  void onThrottleFailure(@NonNull RequestThrottlingException error);
}