hadoop RouterRpcFairnessPolicyController 源码
haddop RouterRpcFairnessPolicyController 代码
文件路径：/hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/fairness/RouterRpcFairnessPolicyController.java
/**
* 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.hdfs.server.federation.fairness;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* Interface to define handlers assignment for specific name services.
* This is needed to allow handlers provide a certain QoS for all name services
* configured. Implementations can choose to define any algorithm which
* would help maintain QoS. This is different when compared to FairCallQueue
* semantics as fairness has a separate context in router based federation.
* An implementation for example, could allocate a dedicated set of handlers
* per name service and allow handlers to continue making downstream name
* node calls if permissions are available, another implementation could use
* preemption semantics and dynamically increase or decrease handlers
* assigned per name service.
*/
@InterfaceAudience.Private
@InterfaceStability.Evolving
public interface RouterRpcFairnessPolicyController {
/**
* Request permission for a specific name service to continue the call and
* connect to downstream name node. Controllers based on policies defined
* and allocations done at start-up through assignHandlersToNameservices,
* may provide a permission or reject the request by throwing exception.
*
* @param nsId NS id for which a permission to continue is requested.
* @return true or false based on whether permit is given.
*/
boolean acquirePermit(String nsId);
/**
* Handler threads are expected to invoke this method that signals
* controller to release the resources allocated to the thread for the
* particular name service. This would mean permissions getting available
* for other handlers to request for this specific name service.
*
* @param nsId Name service id for which permission release request is made.
*/
void releasePermit(String nsId);
/**
* Shutdown steps to stop accepting new permission requests and clean-up.
*/
void shutdown();
/**
* Returns the JSON string of the available handler for each Ns.
*/
String getAvailableHandlerOnPerNs();
}
相关信息
相关文章
hadoop AbstractRouterRpcFairnessPolicyController 源码
hadoop NoRouterRpcFairnessPolicyController 源码
hadoop RefreshFairnessPolicyControllerHandler 源码
hadoop RouterRpcFairnessConstants 源码
0
赞
热门推荐
-
2、 - 优质文章
-
3、 gate.io
-
8、 golang
-
9、 openharmony
-
10、 Vue中input框自动聚焦