hadoop namenode

Under the Cd/home/hadoop/hadoop-2.5.2/binPerformed by the./hdfs Namenode-formatError[Email protected] bin]$/hdfs Namenode–format16/07/11 09:21:21 INFO Namenode. Namenode:startup_msg:/************************************************************Startup_msg:starting NameNodeSta

Hadoop cannot be started properly (1) Failed to start after executing $ bin/hadoop start-all.sh. Exception 1 Exception in thread "Main" Java. Lang. illegalargumentexception: Invalid URI for namenode address (check fs. defaultfs): file: // has no authority. Localhost: At org. Apache. hadoop. HDFS. server.

Click Browserfilesystem. Same as command view resultsWhen we look at the Hadoop source code, we see the Hdfs-default.xml file information under HDFsWe look for ${hadoop.tmp.dir} This is a reference variable, which is definitely defined in other files. As you can see in Core-default.xml, these two profiles have one thing in common:Just do not change this file, but be able to copy information to Core-site.xml and hdfs-site.xml changesUsr/local/

Click Browserfilesystem, and the command to see the results likeWhen we look at the Hadoop source, we see the Hdfs-default.xml file information under HDFsWe look for ${hadoop.tmp.dir} This is a reference variable, certainly in other files are defined, see in Core-default.xml, these two profiles have one thing in common:Just do not modify this file, but you can copy the information to Core-site.xml and hdfs-site.xml to modifyUsr/local/

Preface After a while of hadoop deployment and management, write down this series of blog records. To avoid repetitive deployment, I have written the deployment steps as a script. You only need to execute the script according to this article, and the entire environment is basically deployed. The deployment script I put in the Open Source China git repository (http://git.oschina.net/snake1361222/hadoop_scripts ). All the deployment in this article is b

As you know, Namenode has a single point of failure in the Hadoop system, which has been a weakness for high-availability Hadoop. This article discusses several solution that exist to solve this problem. 1. Secondary NameNode principle: secondary NN periodically reads the editlog from the NN, merging with the image tha

Preface Install the hadoop-2.2.0 64-bit version under Linux CentOS, solve two problems: first, resolve namenode cannot start, view log file logs/ Hadoop-root-namenode-itcast.out (your name is not the same as mine, see the Namenode log file on the line), which throws the fol

Simply put, it is easy for beginners to think That SecondaryNameNode (snn) is a hot standby process of NameNode (nn. It is not. Snn is an integral part of the HDFS architecture, but it is often misunderstood by its name. In fact, it is used to save the backup of HDFS metadata information in namenode, and reduce the restart time of namenode. You still need to do s

Hadoop issue: Start Hadoop times NameNode uninitialized: Java.io.IOException:NameNode is not formatted.1. Start Hadoop[Email protected]:~/hadoop-1.0.4/bin$./start-all.sh starting Namenode, logging to/home/ubuntu/

First, the basic conceptIn MapReduce, an application that is ready to commit execution is called a job, and a unit of work that is divided from one job to run on each compute node is called a task. In addition, the Distributed File System (HDFS) provided by Hadoop is responsible for the data storage of each node and achieves high throughput data reading and writing.Hadoop is a master/slave (Master/slave) architecture for distributed storage and distri

return to the packet downstream of the failed node. 2. Specify a new flag for the current block of data that is stored in another normal datanode, and pass the flag to Namenode so that the fault datanode can delete some of the stored data blocks after recovery. 3. Remove the failed data node from the pipeline and write the remaining data blocks to the two normal datanode in the pipeline. Namenode Notice th

Light literally understood, it is easy for some beginners to assume that: Secondarynamenode (SNN) is the Namenode (NN) hot standby process. Not really. SNN is an integral part of the HDFS architecture, but is often misunderstood for its real purpose by name, in fact its real purpose is to save the namenode of the HDFs metadata information and to reduce the time of namen