hadoop namenode

After hadoop HDFS is deployed, it cannot be used immediately. Instead, you must format the configured file system. Pay attention to the two concepts here. One is a file system. The file system does not exist physically at this time. It may be more appropriate to describe the network disk. The other is formatting, the format here does not refer to the local disk formatting in the traditional sense, but to some cleanup and preparation work. This article

install Hadoop: stand-alone mode : Easy to install, almost no configuration, but limited to debugging purposes;Pseudo-Distribution mode : At the same time, the Namenode, DataNode, Jobtracker, Tasktracker, secondary namenode and other 5 processes are started on a single node, simulating the various nodes of distributed operation;fully distributed mode :

I. Configuration 1. Add the Host Name of the secondary node to the masters file. * Note: The masters file is used to specify the secondary host instead of the namenode. Slaves is used to specify datanode and tasktracker, Namenode is specified by the core-site.xml fs. Default. Name, and jobtracker is specified by the mapred-site.xml mapred. Job. Tracker 2. Modify the hdfs-site.xml File * Note: In fact, DF

production environment Hadoop large cluster fully distributed mode installation 2013-3-7 Installation Environment Operating platform: Vmware2 Operating system: Oracle Enterprise Linux 5.6 Software version: Hadoop-0.22.0,jdk-6u18 Cluster Architecture: Node,master node (hotel01), slave node (hotel02,hotel03 ...) Host name IP System version

Now that namenode and datanode1 are available, add the node datanode2 first step: Modify the Host Name of the node to be added hadoop @ datanode1 :~ $ Vimetchostnamedatanode2 Step 2: Modify the host file hadoop @ datanode1 :~ $ Vimetchosts192.168.8.4datanode2127.0.0.1localhost127.0 Now that namenode and datanode1 are a

Root @ scutshuxue-desktop:/home/root/hadoop-0.19.2 # bin/hadoop FS-put conf input10/07/18 12:31:05 info HDFS. dfsclient: Org. apache. hadoop. IPC. remoteException: Java. io. ioexception: File/user/root/input/log4j. properties cocould only be replicated to 0 nodes, instead of 1At org. Apache. hadoop. HDFS. server.

Hadoop consists of two parts: Distributed File System (HDFS) Distributed Computing framework mapreduce The Distributed File System (HDFS) is mainly used for the Distributed Storage of large-scale data, while mapreduce is built on the Distributed File System to perform distributed computing on the data stored in the distributed file system. Describes the functions of nodes in detail. Namenode: 1. There is o

generally speaking, still suggest to communicate with the IP, after all, in some special cases, the machine name may be in the case of failure.　　4. Create a Hadoop user group, users (Hadoop users should also build a password)[[email protected] root] # groupadd Hadoop useradd-g hadoop-g

Tags: des blog HTTP Io AR for SP file on Recently encountered a problem, the execution of the start-all.sh found that the JPS namenode was not startedThe namenode must be reformatted every time it is started.In fact, the problem lies in the tmp file. The default tmp file is cleared every time it is re-opened, and the formatting information of namenode is lost.So

Generally, one machine in the cluster is specified as namenode, and another machine is specified as jobtracker. These machines areMasters. The remaining Machines serve as datanodeAlsoAs tasktracker. These machines areSlaves Official Address :(Http://hadoop.apache.org/common/docs/r0.19.2/cn/cluster_setup.html) 1 prerequisites Make sure that all required software is installed on each node of your cluster: Sun-JDK, ssh,

NN waits and becomes active when active NN dies I. backupnode can be used in the hadoop-0.21 to implement the namespace of the standby shared storage file system. 3) in order not to cause confusion, we will not use primary or secondary to represent active and standby, because secondary is a checkpoing node in the old version. 4) failover of hot, warm, and cold, standby NN stores the running Active sub-states. I. Cold Standby: standby NN is not in the

In Hadoop version 0.20.1, There is a Bug,namenode synchronization failure in 0.21.0, current Produced a edits.new, and Fsimage synchronization with the exception, and Secondnamenode also produced the same directory structure and data, and reported the following exception:Our secondary name node was not able to start on NullPointerException:ERROR org.apache.hadoop.hdfs.server.namenode.SecondaryNameNode:java

How to control the occurrence frequency of namenode checkpoints The secondarynamenode node regularly accesses namenode to back up image files and edit logs. How can this frequency be modified? This experiment is based on the experiment of separating namenode and secondarynamenode in Hadoop0.20.2 (see). Therefore, this article provides a proof of the correct eff