我正在测试一些基本的 HDFS 操作，比如创建目录。我的测试中有以下集群配置：
import org.apache.hadoop.fs._
import org.apache.hadoop.fs.permission.FsPermission
import org.apache.hadoop.hdfs.{HdfsConfiguration, MiniDFSCluster}
// ...
private val baseDir = new File("./target/hdfs/test").getAbsoluteFile
private val conf = new HdfsConfiguration()
conf.set(MiniDFSCluster.HDFS_MINIDFS_BASEDIR, baseDir.getAbsolutePath)
conf.setInt("dfs.safemode.threshold.pct", 0)
private val builder = new MiniDFSCluster.Builder(conf)
private val cluster = builder.build()
cluster.waitActive()
private val fs = cluster.getFileSystem
private val host = cluster.getNameNode.getHttpAddress.getHostString
private val port = cluster.getNameNodePort
我发现当我运行测试时，我发现我总是得到这个错误：
[warn] o.a.h.s.UserGroupInformation - PriviledgedActionException as:erip (auth:SIMPLE) cause:org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory [...]. Name node is in safe mode.
Resources are low on NN. Please add or free up more resources then turn off safe mode manually. NOTE: If you turn off safe mode before adding resources, the NN will immediately return to safe mode. Use "hdfs dfsadmin -safemode leave" to turn safe mode off.
紧随其后的是...
[info] org.apache.hadoop.ipc.RemoteException: Cannot create directory [...]. Name node is in safe mode.
[info] Resources are low on NN. Please add or free up more resources then turn off safe mode manually. NOTE: If you turn off safe mode before adding resources, the NN will immediately return to safe mode. Use "hdfs dfsadmin -safemode leave" to turn safe mode off.
我正在运行一个内存集群，所以我不知道为什么我会看到这个。我认为设置"dfs.safemode.threshold.pct"会阻止我根据这个答案看到这个错误，但我错了。
为什么我的内存测试集群在安全模式下运行？我该如何阻止它这样做？