hadoop unix commands

Introduction: Most Java programmers use some sort of tracking system to track potential bugs and problems with code in development. However, multithreading and multi-platform environments can generate a lot of puzzling trace data. In this article, software engineer Daniel Would provides some tips to help you understand the trace data that is generated in a complex application. You will learn how to use the Open source logging package log4j to generate a log file that contains rich information. Y

With more than 10 years of windows, and finally changed a high with the Mac, as the saying goes regardless of the front end or back end or toward the Linux, no matter how many PCs will eventually go to the Mac. Not learning command line with what Mac? It's done! Pwd shows the current file path (print working directory) Ls shows the files and folders in the current path (list, not is! the landlord always thought it was Is, always wrong) Mkdir create folder (make directory) Rmdir delete fold

Preface: Well, it's just a little bit more comfortable without writing code, but we can't slack off. The hive operation's file needs to be loaded from hereSimilar to the Linux commands, the command line begins with the Hadoop FS -(dash) LS / list file or directory cat Hadoop FS -cat ./hello.txt/opt/old/ Htt/hello.txt View files can dump directories or

success:mysql-h172.16.77.15-uroot-p123 mysql-h host address-u user name-P user PasswordView Character SetsShow variables like '%char% ';To Modify a character set:VI/ETC/MY.CNF add Default-character-set=utf8 under [client]create sudo without password loginTo set the Aboutyun user with no password sudo permissions: Chmode u+w/etc/sudoersaboutyun all= (root) nopasswd:allchmod u-w/etc/sudoers test: sudo ifconfigUbuntu View Service List codesudo service--status-allsudo initctl listTo view the file s

1. Query IP address ifconfig2. Find port assignments for applications on the servergrep telnet/etc/services (telnet)Telnet using the TCP/UDP port number 23grep domain/etc/services (domain), Telnet Ftp Tftp http Https Snmp Domain Echo Discard Daytime Chargen Time 23 20 69 80 443 161 53 7 9 13 19 37 3.ping [IP Address], test the network for connect

1.hadoopView the directory on HDFs: hadoop fs-ls/ Create a directory on HDFs: -mkdir/jiatest upload the file to HDFs Specify directory: -put test.txt /Jiatest upload jar package to Hadoop run: hadoop jar maven_test-1.0-snapshot.jar org.jiahong.test.WordCount/ jiatest/jiatest/Output View result: -cat/jiatest/output/part-r-000002.linuxU

Hadoop Namenode-format formatted Distributed File systemstart-all.sh Start all Hadoop daemonsstop-all.sh Stop all Hadoop daemonsstart-mapred.sh Start the Map/reduce daemonstop-mapred.sh Stop Map/reduce DaemonStart-dfs.sh starting the HDFs daemonstop-mapred.sh Stop HDFs Daemonstart-balancer.sh HDFS data Block load BalancingFS in the following command can also be w

1.1)vim/etc/udev/rules.d/ --persistent-Net.rulesVI/etc/sysconfig/network-scripts/ifcfg-Eth0type=Ethernetuuid=57d4c2c9-9e9c-48f8-a654-8e5bdbadafb8onboot=yesnm_controlled=YesBootproto = staticDefroute=Yesipv4_failure_fatal=Yesipv6init=NoNAME="System eth0"HWADDR=xx: 0c: in: -: E6:ecipaddr =172.16.53.100PREFIX= -gateway=172.16.53.2Last_connect=1415175123dns1=172.16.53.2The virtual machine's network card is using the virtual network cardSave Exit X or Wq2)Vi/etc/sysconfig/networkNetworking=yesHostnam

From:http://www.2cto.com/database/201303/198460.htmlHadoop HDFs Common CommandsHadoop common commands:Hadoop FSView all commands supported by Hadoop HDFsHadoop fs–lslisting directory and file informationHadoop FS–LSRLoop lists directories, subdirectories, and file informationHadoop fs–put Test.txt/user/sunlightcsCopy the test.txt of the local file system to the/user/sunlightcs directory of the HDFs file sys

, soHDFs has a high degree of fault tolerance.3. High data throughput HDFs uses a "one-time write, multiple read" This simple data consistency model, in HDFS , once a file has been created, written, closed, generally do not need to modify, such a simple consistency model, to improve throughput.4. Streaming data access HDFS has a large scale of data processing, applications need to access a large amount of information at a time, and these applications are generally batch processing, rather than

admin = new hbaseadmin (conf); Admin.disabletable ("account"); Admin.deletetable ("account"); Admin.close ();} @Testpublic void Testput () throws exception{htable table = new htable (conf, "user"); Put put = new put (Bytes.tobytes ("rk0003"));p Ut.add (bytes.tobytes ("info"), Bytes.tobytes ("name"), Bytes.tobytes (" Liuyan ")); Table.put (put); Table.close ();} @Testpublic void Testget () throws exception{htable table = new htable (conf, "user"); Get get = new Get (Bytes.tobytes ("rk0001")); Ge

Modify permissions for a file or directory Chown chown [ options ] User [ . Group ] file/dir Modify the owner of a file Chgrp Chgrp [-R] Group name Dir/file Modify the owning group of a file Iv. Systems and Networks Option name Meaning passwd xxx Change Password Df-ah View disk space Ps-ef |grep View process Kill-9 Kill the process

mytable from Database mydb to the E:\MySQL\mytable.sql file. c:\> mysqldump-h localhost-u root-p mydb mytable>e:\mysql\mytable.sql Example 3: Export the structure of the database mydb to a e:\MySQL\mydb_stru.sql file. c:\> mysqldump-h localhost-u root-p mydb--add-drop-table >e:\mysql\mydb_stru.sql Note :-h localhost can be omitted, it is generally used on the virtual host.3) Export data structure onlyformat : mysqldump-u [Database user name]-p-t [the name of the data

localhost-u root-p mydb >e:\mysql\mydb.sql Then enter the password, wait for an export to succeed, you can check the target file for success. Example 2: Export mytable from Database mydb to the E:\MySQL\mytable.sql file. c:\> mysqldump-h localhost-u root-p mydb mytable>e:\mysql\mytable.sql Example 3: Export the structure of the database mydb to a e:\MySQL\mydb_stru.sql file. c:\> mysqldump-h localhost-u root-p mydb--add-drop-table >e:\mysql\mydb_stru.sql