namenode

namenode

 英

  • 网络名称节点;名字节点;元数据节点

例句

At this point, the NameNode commits the file creation operation into a persistent store.

此时Namenode文件创建操作提交持久存储

You can perform a couple of tests to ensure that Hadoop is up and running normally (at least the namenode).

可以通过几个检查确认Hadoop至少namenode已经启动正常运行

From this, you can see that the namenode is up and able to service the local namespace.

可以看出namenode已经启动能够本地名称空间提供服务

Recall that at the top of the Hadoop cluster is the namenode, which manages the HDFS.

位于Hadoop集群上层namenode管理HDFS

The NameNode executes file system namespace operations like opening, closing, and renaming files and directories.

Namenode执行文件系统namespace操作例如打开关闭重命名文件目录同时决定block具体Datanode节点映射

For this reason, the NameNode can be configured to support maintaining multiple copies of the FsImage and EditLog.

因而Namenode可以配置支持维护多个FsImageEditlog拷贝

The namenode is the master server in Hadoop and manages the file system namespace and access to the files stored in the cluster.

namenodeHadoop服务器管理文件系统名称空间集群存储文件访问

But, due to the characteristics of distributed storage, there are "NameNode" and "DataNode, " which take each of their responsibility.

但是由于分布式存储性质NameNodeDataNode概念它们承担各自责任

They also respond to commands that create, delete, and replicate blocks received from the NameNode.

它们响应NameNode接收创建删除复制命令

The Datanodes also perform block creation, deletion, and replication upon instruction from the Namenode.

数据节点执行来自名字节点建立删除复制指令

Loads are compared by the NameNode and then the details about the free-est neighbor nodes are sent to the specific DataNode.

NameNode比较负载然后有关空闲相邻节点详细信息发送特定DataNode

The NameNode machine is a single point of failure for an HDFS cluster. If the NameNode machine fails, manual intervention is necessary.

NamenodeHDFS存在如果Namenode所在机器错误手工干预必须

When the load increases in a DataNode to the threshold level, it sends a request to the NameNode.

DataNode负载增加阈值级别NameNode发送一个请求

The NameNode had information about the load levels of the specific DataNode's nearest neighbors.

NameNode获得特定DataNode邻近节点负载级别信息

The NameNode keeps an image of the entire file system namespace and file Blockmap in memory.

Namenode内存保存整个文件系统namespace文件Blockmap映像

You'll find one namenode and one secondary namenode in a Hadoop cluster.

每个Hadoop集群可以找到一个namenode一个secondarynamenode

First, request the namenode to format the DFS file system.

首先请求namenodeDFS文件系统进行格式化

The NameNode uses a transaction log called the EditLog to persistently record every change that occurs to file system metadata.

对于任何文件元数据产生修改操作Namenode使用一个称为Editlog事务日志记录下来