sunhelly commented on a change in pull request #3800: URL: https://github.com/apache/hbase/pull/3800#discussion_r763706712
########## File path: hbase-asyncfs/src/main/java/org/apache/hadoop/hbase/io/asyncfs/monitor/ExcludeDatanodeManager.java ########## @@ -0,0 +1,120 @@ +/* + * 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.hbase.io.asyncfs.monitor; + +import java.util.Collections; +import java.util.Map; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.TimeUnit; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.hbase.conf.ConfigurationObserver; +import org.apache.hadoop.hdfs.protocol.DatanodeInfo; +import org.apache.yetus.audience.InterfaceAudience; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; +import org.apache.hbase.thirdparty.com.google.common.cache.Cache; +import org.apache.hbase.thirdparty.com.google.common.cache.CacheBuilder; + +/** + * The class to manage the excluded datanodes of the WALs on the regionserver. + */ +@InterfaceAudience.Private +public class ExcludeDatanodeManager implements ConfigurationObserver { + private static final Logger LOG = LoggerFactory.getLogger(ExcludeDatanodeManager.class); + + /** + * Configure for the max count the excluded datanodes. + */ + private static final String WAL_MAX_EXCLUDE_SLOW_DATANODE_COUNT_KEY = + "hbase.regionserver.async.wal.max.exclude.datanode.count"; + private static final int DEFAULT_WAL_MAX_EXCLUDE_SLOW_DATANODE_COUNT = 3; + + /** + * Configure for the TTL time of the datanodes excluded + */ + private static final String WAL_EXCLUDE_DATANODE_TTL_KEY = + "hbase.regionserver.async.wal.exclude.datanode.info.ttl.hour"; + private static final int DEFAULT_WAL_EXCLUDE_DATANODE_TTL = 6; // 6 hours + + private volatile Cache<DatanodeInfo, Long> excludeDNsCache; Review comment: There is assignment for this variable in the onConfigurationChange(), set it be volatile can make it visible to all the read threads. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@hbase.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
