在hadoop的配置文件 core-site.xml中，需要設置 fs.default.name 或 fs.defaultFS ，具體應該使用哪一個，會造什么樣的錯誤，需要在實際操作中去驗證。官網有下面這段描述
We need to have only one of the two (fs.default.name or fs.defaultFS, and the former is deprecated). If both are present then NN HA will be enabled/disabled based on what is read first.
Following is description from NN HA in Apache docs:
fs.defaultFS - the default path prefix used by the Hadoop FS client when none is given.
Optionally, you may now configure the default path for Hadoop clients to use the new HA-enabled logical URI. If you used "mycluster" as the nameservice ID earlier, this will be the value of the authority portion of all of your HDFS paths. This may be configured like so, in your core-site.xml file:
<property>
<name>fs.defaultFS</name>
<value>hdfs://mycluster</value>
</property>
從文檔中可以看出，使用 fs.default.name 還是 使用 fs.defaultFS ，要首先判斷是否開啟了 NN 的HA (namenode 的 highavaliable)，如果開啟了nn ha，那么就用fs.defaultFS，在單一namenode的情況下，就用 fs.default.name , 如果在單一namenode節點的情況使用 fs.defaultFS ，系統將報
ERROR org.apache.hadoop.hdfs.server.namenode.NameNode: Failed to start namenode.
java.lang.IllegalArgumentException: Invalid URI for NameNode address (check fs.defaultFS): file:/// has no authority.
at org.apache.hadoop.hdfs.server.namenode.NameNode.getAddress(NameNode.java:471)
at org.apache.hadoop.hdfs.server.namenode.NameNode.getAddress(NameNode.java:461)
at org.apache.hadoop.hdfs.server.namenode.NameNode.getRpcServerAddress(NameNode.java:512)
at org.apache.hadoop.hdfs.server.namenode.NameNode.loginAsNameNodeUser(NameNode.java:612)
at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:632)
at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:811)
at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:795)
at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1488)
at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1554)
INFO org.apache.hadoop.util.ExitUtil: Exiting with status 1
INFO org.apache.hadoop.hdfs.server.namenode.NameNode: SHUTDOWN_MSG:
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原文鏈接：https://blog.csdn.net/lepton126/article/details/88327205