org.apache.hadoop.yarn.api.ClientSCMProtocol Maven / Gradle / Ivy
/**
* 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.Public;
import org.apache.hadoop.classification.InterfaceStability.Unstable;
import org.apache.hadoop.yarn.api.protocolrecords.ReleaseSharedCacheResourceRequest;
import org.apache.hadoop.yarn.api.protocolrecords.ReleaseSharedCacheResourceResponse;
import org.apache.hadoop.yarn.api.protocolrecords.UseSharedCacheResourceRequest;
import org.apache.hadoop.yarn.api.protocolrecords.UseSharedCacheResourceResponse;
import org.apache.hadoop.yarn.api.records.ApplicationId;
import org.apache.hadoop.yarn.exceptions.YarnException;
/**
*
* The protocol between clients and the SharedCacheManager to claim
* and release resources in the shared cache.
*
*/
@Public
@Unstable
public interface ClientSCMProtocol {
/**
*
* The interface used by clients to claim a resource with the
* SharedCacheManager. The client uses a checksum to identify the
* resource and an {@link ApplicationId} to identify which application will be
* using the resource.
*
*
*
* The SharedCacheManager responds with whether or not the
* resource exists in the cache. If the resource exists, a Path
* to the resource in the shared cache is returned. If the resource does not
* exist, the response is empty.
*
*
* @param request request to claim a resource in the shared cache
* @return response indicating if the resource is already in the cache
* @throws YarnException
* @throws IOException
*/
public UseSharedCacheResourceResponse use(
UseSharedCacheResourceRequest request) throws YarnException, IOException;
/**
*
* The interface used by clients to release a resource with the
* SharedCacheManager. This method is called once an application
* is no longer using a claimed resource in the shared cache. The client uses
* a checksum to identify the resource and an {@link ApplicationId} to
* identify which application is releasing the resource.
*
*
*
* Note: This method is an optimization and the client is not required to call
* it for correctness.
*
*
*
* Currently the SharedCacheManager sends an empty response.
*
*
* @param request request to release a resource in the shared cache
* @return (empty) response on releasing the resource
* @throws YarnException
* @throws IOException
*/
public ReleaseSharedCacheResourceResponse release(
ReleaseSharedCacheResourceRequest request) throws YarnException, IOException;
}