/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.hadoop.yarn.api;

import java.io.IOException;

import org.apache.hadoop.classification.InterfaceAudience.Private;
import org.apache.hadoop.classification.InterfaceAudience.Public;
import org.apache.hadoop.classification.InterfaceStability.Stable;
import org.apache.hadoop.classification.InterfaceStability.Unstable;
import org.apache.hadoop.io.retry.Idempotent;
import org.apache.hadoop.yarn.api.protocolrecords.CancelDelegationTokenRequest;
import org.apache.hadoop.yarn.api.protocolrecords.CancelDelegationTokenResponse;
import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationAttemptReportRequest;
import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationAttemptReportResponse;
import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationAttemptsRequest;
import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationAttemptsResponse;
import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationReportRequest;
import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationReportResponse;
import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationsRequest;
import org.apache.hadoop.yarn.api.protocolrecords.GetApplicationsResponse;
import org.apache.hadoop.yarn.api.protocolrecords.GetContainerReportRequest;
import org.apache.hadoop.yarn.api.protocolrecords.GetContainerReportResponse;
import org.apache.hadoop.yarn.api.protocolrecords.GetContainersRequest;
import org.apache.hadoop.yarn.api.protocolrecords.GetContainersResponse;
import org.apache.hadoop.yarn.api.protocolrecords.GetDelegationTokenRequest;
import org.apache.hadoop.yarn.api.protocolrecords.GetDelegationTokenResponse;
import org.apache.hadoop.yarn.api.protocolrecords.RenewDelegationTokenRequest;
import org.apache.hadoop.yarn.api.protocolrecords.RenewDelegationTokenResponse;
import org.apache.hadoop.yarn.api.records.ApplicationAttemptId;
import org.apache.hadoop.yarn.api.records.ApplicationAttemptReport;
import org.apache.hadoop.yarn.api.records.ApplicationId;
import org.apache.hadoop.yarn.api.records.ApplicationReport;
import org.apache.hadoop.yarn.api.records.ContainerId;
import org.apache.hadoop.yarn.api.records.ContainerReport;
import org.apache.hadoop.yarn.api.records.Token;
import org.apache.hadoop.yarn.exceptions.YarnException;

/**
 * <p>
 * The protocol between clients and the <code>ResourceManager</code> or
 * <code>ApplicationHistoryServer</code> to get information on applications,
 * application attempts and containers.
 * </p>
 *
 */
@Private
@Unstable
public interface ApplicationBaseProtocol {

  /**
   * The interface used by clients to get a report of an Application from the
   * <code>ResourceManager</code> or <code>ApplicationHistoryServer</code>.
   * <p>
   * The client, via {@link GetApplicationReportRequest} provides the
   * {@link ApplicationId} of the application.
   * <p>
   * In secure mode,the <code>ResourceManager</code> or
   * <code>ApplicationHistoryServer</code> verifies access to the application,
   * queue etc. before accepting the request.
   * <p>
   * The <code>ResourceManager</code> or <code>ApplicationHistoryServer</code>
   * responds with a {@link GetApplicationReportResponse} which includes the
   * {@link ApplicationReport} for the application.
   * <p>
   * If the user does not have <code>VIEW_APP</code> access then the following
   * fields in the report will be set to stubbed values:
   * <ul>
   *   <li>host - set to "N/A"</li>
   *   <li>RPC port - set to -1</li>
   *   <li>client token - set to "N/A"</li>
   *   <li>diagnostics - set to "N/A"</li>
   *   <li>tracking URL - set to "N/A"</li>
   *   <li>original tracking URL - set to "N/A"</li>
   *   <li>resource usage report - all values are -1</li>
   * </ul>
   *
   * @param request
   *          request for an application report
   * @return application report
   * @throws YarnException exceptions from yarn servers.
   * @throws IOException io error occur.
   */
  @Public
  @Stable
  @Idempotent
  public GetApplicationReportResponse getApplicationReport(
      GetApplicationReportRequest request) throws YarnException, IOException;

  /**
   * <p>
   * The interface used by clients to get a report of Applications matching the
   * filters defined by {@link GetApplicationsRequest} in the cluster from the
   * <code>ResourceManager</code> or <code>ApplicationHistoryServer</code>.
   * </p>
   *
   * <p>
   * The <code>ResourceManager</code> or <code>ApplicationHistoryServer</code>
   * responds with a {@link GetApplicationsResponse} which includes the
   * {@link ApplicationReport} for the applications.
   * </p>
   *
   * <p>
   * If the user does not have <code>VIEW_APP</code> access for an application
   * then the corresponding report will be filtered as described in
   * {@link #getApplicationReport(GetApplicationReportRequest)}.
   * </p>
   *
   * @param request
   *          request for report on applications
   * @return report on applications matching the given application types defined
   *         in the request
   * @throws YarnException exceptions from yarn servers.
   * @throws IOException io error occur.
   * @see GetApplicationsRequest
   */
  @Public
  @Stable
  @Idempotent
  public GetApplicationsResponse
      getApplications(GetApplicationsRequest request) throws YarnException,
          IOException;

  /**
   * The interface used by clients to get a report of an Application Attempt
   * from the <code>ResourceManager</code> or
   * <code>ApplicationHistoryServer</code>
   * <p>
   * The client, via {@link GetApplicationAttemptReportRequest} provides the
   * {@link ApplicationAttemptId} of the application attempt.
   * <p>
   * In secure mode,the <code>ResourceManager</code> or
   * <code>ApplicationHistoryServer</code> verifies access to the method before
   * accepting the request.
   * <p>
   * The <code>ResourceManager</code> or <code>ApplicationHistoryServer</code>
   * responds with a {@link GetApplicationAttemptReportResponse} which includes
   * the {@link ApplicationAttemptReport} for the application attempt.
   * <p>
   * If the user does not have <code>VIEW_APP</code> access then the following
   * fields in the report will be set to stubbed values:
   * <ul>
   *   <li>host</li>
   *   <li>RPC port</li>
   *   <li>client token</li>
   *   <li>diagnostics - set to "N/A"</li>
   *   <li>tracking URL</li>
   * </ul>
   *
   * @param request
   *          request for an application attempt report
   * @return application attempt report
   * @throws YarnException exceptions from yarn servers.
   * @throws IOException io error occur.
   */
  @Public
  @Unstable
  @Idempotent
  public GetApplicationAttemptReportResponse getApplicationAttemptReport(
      GetApplicationAttemptReportRequest request) throws YarnException,
      IOException;

  /**
   * <p>
   * The interface used by clients to get a report of all Application attempts
   * in the cluster from the <code>ResourceManager</code> or
   * <code>ApplicationHistoryServer</code>
   * </p>
   *
   * <p>
   * The <code>ResourceManager</code> or <code>ApplicationHistoryServer</code>
   * responds with a {@link GetApplicationAttemptsRequest} which includes the
   * {@link ApplicationAttemptReport} for all the applications attempts of a
   * specified application attempt.
   * </p>
   *
   * <p>
   * If the user does not have <code>VIEW_APP</code> access for an application
   * then the corresponding report will be filtered as described in
   * {@link #getApplicationAttemptReport(GetApplicationAttemptReportRequest)}.
   * </p>
   *
   * @param request
   *          request for reports on all application attempts of an application
   * @return reports on all application attempts of an application
   * @throws YarnException exceptions from yarn servers.
   * @throws IOException io error occur.
   */
  @Public
  @Unstable
  @Idempotent
  public GetApplicationAttemptsResponse getApplicationAttempts(
      GetApplicationAttemptsRequest request) throws YarnException, IOException;

  /**
   * <p>
   * The interface used by clients to get a report of an Container from the
   * <code>ResourceManager</code> or <code>ApplicationHistoryServer</code>
   * </p>
   *
   * <p>
   * The client, via {@link GetContainerReportRequest} provides the
   * {@link ContainerId} of the container.
   * </p>
   *
   * <p>
   * In secure mode,the <code>ResourceManager</code> or
   * <code>ApplicationHistoryServer</code> verifies access to the method before
   * accepting the request.
   * </p>
   *
   * <p>
   * The <code>ResourceManager</code> or <code>ApplicationHistoryServer</code>
   * responds with a {@link GetContainerReportResponse} which includes the
   * {@link ContainerReport} for the container.
   * </p>
   *
   * @param request
   *          request for a container report
   * @return container report
   * @throws YarnException exceptions from yarn servers.
   * @throws IOException io error occur.
   */
  @Public
  @Unstable
  @Idempotent
  public GetContainerReportResponse getContainerReport(
      GetContainerReportRequest request) throws YarnException, IOException;

  /**
   * <p>
   * The interface used by clients to get a report of Containers for an
   * application attempt from the <code>ResourceManager</code> or
   * <code>ApplicationHistoryServer</code>
   * </p>
   *
   * <p>
   * The client, via {@link GetContainersRequest} provides the
   * {@link ApplicationAttemptId} of the application attempt.
   * </p>
   *
   * <p>
   * In secure mode,the <code>ResourceManager</code> or
   * <code>ApplicationHistoryServer</code> verifies access to the method before
   * accepting the request.
   * </p>
   *
   * <p>
   * The <code>ResourceManager</code> or <code>ApplicationHistoryServer</code>
   * responds with a {@link GetContainersResponse} which includes a list of
   * {@link ContainerReport} for all the containers of a specific application
   * attempt.
   * </p>
   *
   * @param request
   *          request for a list of container reports of an application attempt.
   * @return reports on all containers of an application attempt
   * @throws YarnException exceptions from yarn servers.
   * @throws IOException io error occur.
   */
  @Public
  @Unstable
  @Idempotent
  public GetContainersResponse getContainers(GetContainersRequest request)
      throws YarnException, IOException;

  /**
   * <p>
   * The interface used by clients to get delegation token, enabling the
   * containers to be able to talk to the service using those tokens.
   *
   * <p>
   * The <code>ResourceManager</code> or <code>ApplicationHistoryServer</code>
   * responds with the delegation {@link Token} that can be used by the client
   * to speak to this service.
   *
   * @param request
   *          request to get a delegation token for the client.
   * @return delegation token that can be used to talk to this service
   * @throws YarnException exceptions from yarn servers.
   * @throws IOException io error occur.
   */
  @Public
  @Stable
  @Idempotent
  public GetDelegationTokenResponse getDelegationToken(
      GetDelegationTokenRequest request) throws YarnException, IOException;

  /**
   * Renew an existing delegation {@link Token}.
   *
   * @param request
   *          the delegation token to be renewed.
   * @return the new expiry time for the delegation token.
   * @throws YarnException exceptions from yarn servers.
   * @throws IOException io error occur.
   */
  @Private
  @Unstable
  @Idempotent
  public RenewDelegationTokenResponse renewDelegationToken(
      RenewDelegationTokenRequest request) throws YarnException, IOException;

  /**
   * Cancel an existing delegation {@link Token}.
   *
   * @param request
   *          the delegation token to be cancelled.
   * @return an empty response.
   * @throws YarnException exceptions from yarn servers.
   * @throws IOException io error occur.
   */
  @Private
  @Unstable
  @Idempotent
  public CancelDelegationTokenResponse cancelDelegationToken(
      CancelDelegationTokenRequest request) throws YarnException, IOException;

}
