【发布时间】：2019-04-13 00:59:11
【问题描述】：
在设置多节点 hadoop 集群时，我遇到了几个问题。
通过不同的门户网站进行正确设置。出现了一些基本问题
我正在使用 Hadoop 2.8.5 在主从配置中设置 2 节点集群。
在第一个机器格式上，namenode 使用hdfs namenode format
clusterID 和 BlockpoolID 分配如下：
#Fri Mar 29 11:14:41 IST 2019
namespaceID=576041649
clusterID=CID-98480e8d-f7a9-4e1a-8997-400a7aa150c3
cTime=1553838281164
storageType=NAME_NODE
blockpoolID=BP-954411427-x.x.x.y-1553838281164
layoutVersion=-63
现在在第二台机器上，我运行了命令hdfs namenode format -clusterId CID-98480e8d-f7a9-4e1a-8997-400a7aa150c3
#Fri Mar 29 11:15:38 IST 2019
namespaceID=304822257
clusterID=CID-98480e8d-f7a9-4e1a-8997-400a7aa150c3
cTime=1553838338130
storageType=NAME_NODE
blockpoolID=BP-1421744029-x.x.x.x-1553838338130
layoutVersion=-63
考虑到slave和master应该有相同的clusterID，如果我错了，请纠正我。
配置似乎工作正常，但在logs/hadoop-cassandra-datanode-localnosql1.log 和logs/hadoop-cassandra-datanode-localnosql2.log 的日志中出现错误
2019-03-29 11:25:44,009 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for Block pool BP-954411427-x.x.x.y-1553838281164 (Datanode Uuid 4b90bebb-3c34-43d5-8285-6ec6dfefc0a7) service to localnosql1/x.x.x.x:8020 Blockpool ID mismatch: previously connected to Blockpool ID BP-954411427-x.x.x.y-1553838281164 but now connected to Blockpool ID BP-1421744029-x.x.x.x-1553838338130
2019-03-29 11:25:49,010 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for Block pool BP-954411427-x.x.x.y-1553838281164 (Datanode Uuid 4b90bebb-3c34-43d5-8285-6ec6dfefc0a7) service to localnosql1/x.x.x.x:8020 Blockpool ID mismatch: previously connected to Blockpool ID BP-954411427-x.x.x.y-1553838281164 but now connected to Blockpool ID BP-1421744029-x.x.x.x-1553838338130
2019-03-29 11:25:54,012 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for Block pool BP-954411427-x.x.x.y-1553838281164 (Datanode Uuid 4b90bebb-3c34-43d5-8285-6ec6dfefc0a7) service to localnosql1/x.x.x.x:8020 Blockpool ID mismatch: previously connected to Blockpool ID BP-954411427-x.x.x.y-1553838281164 but now connected to Blockpool ID BP-1421744029-x.x.x.x-1553838338130
2019-03-29 11:25:59,013 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for Block pool BP-954411427-x.x.x.y-1553838281164 (Datanode Uuid 4b90bebb-3c34-43d5-8285-6ec6dfefc0a7) service to localnosql1/x.x.x.x:8020 Blockpool ID mismatch: previously connected to Blockpool ID BP-954411427-x.x.x.y-1553838281164 but now connected to Blockpool ID BP-1421744029-x.x.x.x-1553838338130
2019-03-29 11:26:04,014 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for Block pool BP-954411427-x.x.x.y-1553838281164 (Datanode Uuid 4b90bebb-3c34-43d5-8285-6ec6dfefc0a7) service to localnosql1/x.x.x.x:8020 Blockpool ID mismatch: previously connected to Blockpool ID BP-954411427-x.x.x.y-1553838281164 but now connected to Blockpool ID BP-1421744029-x.x.x.x-1553838338130
这些错误日志表明了什么？
所有主从节点上的blockpool ID是否需要和clusterId一样，如果是怎么做？
【问题讨论】：