http://essayboard.com/2011/05/28/raising-ulimit-on-centos-server/ $ su - # vi /etc/sysctl.conf (add fs.file-max = [value] at the end of the file) # sysctl -p # vi /etc/security/limits.conf (add [type] - nofile [value] like below; hdfs - nofile [value] hbase - nofile [value] * - nofile [value] # ulimit -n [value] # ulimit -n

http://hook.tistory.com/entry/RHEL-CentOS%EC%97%90%EC%84%9C-ntp-%EC%84%9C%EB%B2%84-%EC%84%A4%EC%A0%95%ED%95%98%EA%B8%B0%EC%82%AC%EC%84%A4%EB%A7%9D-%EB%82%B4%EB%B6%80-%EC%84%9C%EB%B2%84%EB%93%A4%EC%9D%98-%EC%8B%9C%EA%B0%84-%EB%8F%99%EA%B8%B0%ED%99%94 server1: x.y.w.z1 server2: x.y.w.z2 server3: x.y.w.z3 all servers # yum install ntp -y server1 # vi /etc/ntp.conf # Permit time synchronization with..

http://stackoverflow.com/questions/1239579/helper-in-order-to-remove-null-reference-in-java-list import java.util.*; public class ListTest { public static void main(String[] args) { final ListiList=new ArrayList(); for ( int i = 0; i < 10; ++i ){ if ( i % 2 == 0 )iList.add(i); elseiList.add(null); } iList.remove(0); System.out.println(iList + "\tsize " + iList.size()); iList.removeAll(Collection..

http://www.debianadmin.com/howto-install-java6-on-debian-etch.html $ sudo vi /etc/apt/sources.list add "deb http://ftp.debian.org/debian unstable non-free" $ sudo apt-get update $ sudo apt-get install sun-java6-jdk $ sudo vi /etc/apt/sources.list $ sudo update-java-alternatives -s java-6-sun $ sudo vi /etc/apt/sources.list remove "deb http://ftp.debian.org/debian unstable non-free"

http://www.tolaris.com/2009/03/05/using-host-networking-and-nat-with-virtualbox/

Cent OS during installation select only 'server' package manual setting for IP address manual setting for DNS after installation # yum -y update # /etc/init.d/ssh start set service which need to start automatically http://frucyan.tistory.com/entry/%EC%84%9C%EB%B9%84%EC%8A%A4-%EC%9E%90%EB%8F%99-%EC%8B%9C%EC%9E%91 http://apollo89.com/blog/329 # ntsysv CDH Prerequisite add user for servers http://o..

case 1. dump monetdb database into file (escape sequences show like '\t', '\n' properly) 2. split it into table by table using bash script (escape sequences show like 't', 'n') 3. bulk input table dump file into other database problem: cannot write escape sequence properly (want: '\t', '\n' / real: 't', 'n') solution: use eight back slashes ... _line=`echo $_line | sed 's/'\''\([t|n]\)'\''/'\''\..

2011/08/05 - [Programming] - monetdb SQLException:str_cast:value too long for type (var)char([number]) http://bugs.monetdb.org/show_bug.cgi?id=2847 1. MSSQL의 table을 export해 txt로, 다시 monetdb의 table로 import하는 과정에서 발생 문제를 일으킨 field는 MSSQL에서는 nvarchar(n)으로, monetdb에서는 varchar(n)으로 선언 값을 실제로 읽어봐도 n을 넘는 값은 없었으나, 위의 exception은 계속 발생 검색을 통해 알아보니 nvarchar는 UTF8이고 변환후 ascii를 입력하는 과정에서 발생한 것으로 판단하여, monetd..

import java.util.Set; import java.util.Iterator; import redis.clients.jedis.Jedis; import redis.clients.jedis.JedisPool; import redis.clients.jedis.JedisPoolConfig; public class TestJedisSortedSet{ public static void main(String[] args){ JedisPool pool = new JedisPool(new JedisPoolConfig(), "flatbox"); Jedis jedis = pool.getResource(); try { intELEMENTS_NUM=3; //sorted set final String[]sortedSe..

import java.util.Set; import java.util.Iterator; import redis.clients.jedis.Jedis; import redis.clients.jedis.JedisPool; import redis.clients.jedis.JedisPoolConfig; public class TestJedisSet{ public static void main(String[] args){ JedisPool pool = new JedisPool(new JedisPoolConfig(), "flatbox"); Jedis jedis = pool.getResource(); try { intELEMENTS_NUM=3; //set final String[]sets={ "set1", "set2"..