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使用hdfs namenode format的namenode
clusterID和BlockpoolID被分配如下：
#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，但我在logs/hadoop-cassandra-datanode-localnosql1.log和logs/hadoop-cassandra-datanode-localnosql2.log的日志中收到错误
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？
所有主节点和从节点上的块池ID是否需要与clusterId相同，如果是，如何执行此操作？
你为什么要尝试两次格式化namenode？理想情况下，在多节点配置中，有一个名称节点和许多数据节点。在第一次设置时，通过“hdfs namenode -format”初始化namenode然后启动datanode并且它工作正常。
如果您正在尝试多主配置（同时运行多个namenode），我不确定这是否有效。
如果您正在尝试使用namenode进行活动 - 备用配置，则可以尝试以下步骤