namenode and datanode in hadoop

Recently in the application of Hadoop cluster, encountered the task to submit the cluster, long-time card in the accepted state, the application of resources difficult situation, after a series of log analysis, the state of the investigation, only to find that the namenode has been caused by the primary and standby switch, The previous Namenode primary node has b

　　ObjectiveWhen you build a Hadoop cluster, the first time you format it, take a snapshot . Do not casually lack of any process, just a format.　　problem description : start Hadoop times NameNode uninitialized: Java.io.IOException:NameNode is notformatted.At the same time, if you start the Namenode alone, it will appear

/************************************************************Startup_msg:starting NameNodeStartup_msg:host = master/192.168.2.1Startup_msg:args = []Startup_msg:version = 0.20.2Startup_msg:build = Https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.20-r 911707; Compiled by ' chrisdo ' on Fri 08:07:34 UTC 2010************************************************************/2015-10-17 09:09:11,197 INFO org.apache.hadoop.ipc.metrics.RpcMetrics:In

Hadoop DataNode Add Disk 1. Disk formatting Mkfs-t EXT4/DEV/XVDD 2. Mount the disk Vim/etc/fstab; Mount-a 3. Create Datanode Data Catalog Mkdir-p/data2/hadoopdata3/dfs/data//data2/hadoopdata4/dfs/data/ Chown Hbase.hbase-r/DATA2/HADOOPDATA3/DATA2/HADOOPDATA4 4. Close Datanode Cd/opt/

For example, if the ip address of the newly added node is 192.168.1.xxx, add the hosts of 192.168.1.xxxdatanode-xxx to all nn and dn nodes, create useraddhadoop-sbinbash-m on xxx, and add the ip address of another dn. all files in ssh are copied to homehadoop on xxx. install jdkapt-getinstallsun-java6-j in ssh path For example, if the ip address of the newly added node is 192.168.1.xxx, add the hosts of 192.168.1.xxx datanode-xxx to all nn and dn node

When I first got to know hadoop, I had to configure a hadoop cluster on a 7-7-8 basis. However, when I had a big hurdle, I often fell victim to the ship. Every time you execute hadoop namenode-format to format the hadoop file system, an error is always reported. As a result

Add several new nodes to a running hadoop Cluster 1. Deploy the Java/hadoop program on the new node and configure the corresponding environment variables. 2. Add users to the new node, copy id_rsa.pub from the master, and configure authorized_keys 3. Set the host on the new node, as long as there is a host of the Local Machine and the master. 4. Create related directories on the new node and modify the owne

To make it easy to customize the presentation in the management interface of Hadoop (Namenode and Jobtracker), the management interface of Hadoop is implemented using proxy servlet.First of allThe constructors in Org.apache.hadoop.http.HttpServer public httpserver (string name, string bindaddress, int Port,boolean findport, Configuration conf, accesscontrollist a

BenCodeFunction: Get the datanode name and write it to the file in the HDFS file system.HDFS: // copyoftest. C. And count filesHDFS: // wordcount count in copyoftest. C,Unlike hadoop's examples, which reads files from the local file system. Package Com. fora; Import Java. Io. ioexception; Import Java. util. stringtokenizer; Import Org. Apache. hadoop. conf. configuration; Import Org. Apache.

After the hadoop cluster is started, run the JPS command to view the process. Only the tasktracker process is found on the datanode node, as shown in. Master process:Two Slave node processes found that there was no datanode process on the salve node. after checking the log, we found that the data directory permission on data