[Hadoop] Install Hadoop as Standalone in CentOS 7

1. Install RSync

#> yum -y install rsync

2. Download Hadoop

http://hadoop.apache.org/releases.html

#> cd /usr/local
#> wget http://www.apache.org/dyn/closer.cgi/hadoop/common/hadoop-2.8.1/hadoop-2.8.1.tar.gz

3. Unzip Hadoop file

#> tar zxf hadoop-2.8.1.tar.gz

4. Setup environment variables

#> cd /usr/local/hadoop-2.8.1/etc/hadoop
#> vi hadoop-env.sh

#> vi ~/.bash_profile

5. Configure core-site.xml file

#> cd /usr/local/hadoop-2.8.1/etc/hadoop
#> vi core-site.xml

6. Configure hdfs-site.xml

#> cd /usr/local/hadoop-2.8.1/etc/hadoop
#> vi hdfs-site.xml

7. Create SSH key

#> ssh-keygen -t rsa
#> cp ~/.ssh/id_rsa.pub ~/.ssh/authorized_keys

8. Test SSH

#> ssh localhost

9. Format NameNode

#> hadoop namenode -format

10. Startup Hadoop

#> start-all.sh

11. Connect on Web browser

http://hadoophost:50070

[CentOS] Setup FTP when SElinux is enabled

1. Set FTP User home directory (FTP 유저 홈디렉터리 설정)

#> chown -R ftp:ftp /var/ftp
#> semanage fcontext -a -t public_content_rw_t /var/ftp
#> restorecon -Rvv /var/ftp
#> setsebool -P ftp_home_dir 1
#> setsebool -P ftpd_full_access 1
#> ls -lZ /var | grep ftp

2. Restart FTP service

# Set FTP service auto enable
#> systemctl enable vsftpd

# Restart FTP Server
#> systemctl restart vsftpd

[CentOS] Set enable to connect FTP server by root user

1. Edit /etc/vsftpd/user_list and exclude root user

#> vi /etc/vsftpd/user_list

2. Edit /etc/vsftpd/ftpusers and exclude root user

#> /etc/vsftpd/ftpusers

[Java] How to get OS name, version, CPU Architecture from System.property(String)

System.getProperty("os.name");
System.getProperty("os.version");
System.getProperty("os.arch");

os.name	os.version	os.arch	Comments
Linux	2.0.31	x86 IBM	Java 1.3
Linux	(*)	i386	Sun Java 1.3.1, 1.4 or Blackdown Java; (*) os.version depends on Linux Kernel version
Linux	(*)	x86_64	Blackdown Java; note x86_64 might change to amd64; (*) os.version depends on Linux Kernel version
Linux	(*)	sparc	Blackdown Java; (*) os.version depends on Linux Kernel version
Linux	(*)	ppc	Blackdown Java; (*) os.version depends on Linux Kernel version
Linux	(*)	armv41	Blackdown Java; (*) os.version depends on Linux Kernel version
Linux	(*)	i686	GNU Java Compiler (GCJ); (*) os.version depends on Linux Kernel version
Linux	(*)	ppc64	IBM Java 1.3; (*) os.version depends on Linux Kernel version
Mac OS	7.5.1	PowerPC
Mac OS	8.1	PowerPC
Mac OS	9.0, 9.2.2	PowerPC	MacOS 9.0: java.version=1.1.8, mrj.version=2.2.5; MacOS 9.2.2: java.version=1.1.8 mrj.version=2.2.5
Mac OS X	10.1.3	ppc
Mac OS X	10.2.6	ppc	Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1_01-39) Java HotSpot(TM) Client VM (build 1.4.1_01-14, mixed mode)
Mac OS X	10.2.8	ppc	using 1.3 JVM: java.vm.version=1.3.1_03-74, mrj.version=3.3.2; using 1.4 JVM: java.vm.version=1.4.1_01-24, mrj.version=69.1
Mac OS X	10.3.1, 10.3.2, 10.3.3, 10.3.4	ppc	JDK 1.4.x
Mac OS X	10.3.8	ppc	Mac OS X 10.3.8 Server; using 1.3 JVM: java.vm.version=1.3.1_03-76, mrj.version=3.3.3; using 1.4 JVM: java.vm.version=1.4.2-38; mrj.version=141.3
Windows 95	4.0	x86
Windows 98	4.10	x86	Note, that if you run Sun JDK 1.2.1 or 1.2.2 Windows 98 identifies itself as Windows 95.
Windows Me	4.90	x86
Windows NT	4.0	x86
Windows 2000	5.0	x86
Windows XP	5.1	x86	Note, that if you run older Java runtimes Windows XP identifies itself as Windows 2000.
Windows 2003	5.2	x86	java.vm.version=1.4.2_06-b03; Note, that Windows Server 2003 identifies itself only as Windows 2003.
Windows CE	3.0 build 11171	arm	Compaq iPAQ 3950 (PocketPC 2002)
OS/2	20.40	x86
Solaris	2.x	sparc
SunOS	5.7	sparc	Sun Ultra 5 running Solaris 2.7
SunOS	5.8	sparc	Sun Ultra 2 running Solaris 8
SunOS	5.9	sparc	Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0_01-b03) Java HotSpot(TM) Client VM (build 1.4.0_01-b03, mixed mode)
MPE/iX	C.55.00	PA-RISC
HP-UX	B.10.20	PA-RISC	JDK 1.1.x
HP-UX	B.11.00	PA-RISC	JDK 1.1.x
HP-UX	B.11.11	PA-RISC	JDK 1.1.x
HP-UX	B.11.11	PA_RISC	JDK 1.2.x/1.3.x; note Java 2 returns PA_RISC and Java 1 returns PA-RISC
HP-UX	B.11.00	PA_RISC	JDK 1.2.x/1.3.x
HP-UX	B.11.23	IA64N	JDK 1.4.x
HP-UX	B.11.11	PA_RISC2.0	JDK 1.3.x or JDK 1.4.x, when run on a PA-RISC 2.0 system
HP-UX	B.11.11	PA_RISC	JDK 1.2.x, even when run on a PA-RISC 2.0 system
HP-UX	B.11.11	PA-RISC	JDK 1.1.x, even when run on a PA-RISC 2.0 system
AIX	5.2	ppc64	sun.arch.data.model=64
AIX	4.3	Power
AIX	4.1	POWER_RS
OS/390	390	02.10.00	J2RE 1.3.1 IBM OS/390 Persistent Reusable VM
FreeBSD	2.2.2-RELEASE	x86
Irix	6.3	mips
Digital Unix	4.0	alpha
NetWare 4.11	4.11	x86
OSF1	V5.1	alpha	Java 1.3.1 on Compaq (now HP) Tru64 Unix V5.1
OpenVMS	V7.2-1	alpha	Java 1.3.1_1 on OpenVMS 7.2

Reference : http://lopica.sourceforge.net/os.html