Linux集群时间同步设置

集群时间同步 是hadoop hbase等分布式框架的一个常见问题。所以记录下来。

本文转载自：http://jerrylead.iteye.com/blog/1179492

打算将11台Linux集群时间同步一下，操作系统都为Ubuntu 11.04 x86 64位

选定其中一台133.133.10.2作为时间服务器（ntp server），其他节点与该节点进行时间同步。
 
1、在133.133.10.2（monitor）上安装ntp server。
root@monitor:~# apt-get install ntp
 
2、修改/etc/ntp.conf如下：（参考了http://blog.sina.com.cn/s/blog_6b86fdc50100ojfn.html）
 
 
# /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help
 
driftfile /var/lib/ntp/ntp.drift
 
 
# Enable this if you want statistics to be logged.
#statsdir /var/log/ntpstats/
 
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable
 
# Specify one or more NTP servers.
 
# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
# on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for
# more information.
#server 0.ubuntu.pool.ntp.org
#server 1.ubuntu.pool.ntp.org
#server 2.ubuntu.pool.ntp.org
#server 3.ubuntu.pool.ntp.org
 
# Use Ubuntu's ntp server as a fallback.
#server ntp.ubuntu.com
server 127.127.1.0 minpoll 4 maxpoll 5
fudge 127.127.1.0 stratum 2
 
# Access control configuration; see /usr/share/doc/ntp-doc/html/accopt.html for
# details.  The web page <http://support.ntp.org/bin/view/Support/AccessRestrictions>
# might also be helpful.
#
# Note that "restrict" applies to both servers and clients, so a configuration
# that might be intended to block requests from certain clients could also end
# up blocking replies from your own upstream servers.
 
# By default, exchange time with everybody, but don't allow configuration.
#restrict -4 default kod notrap nomodify nopeer noquery
#restrict -6 default kod notrap nomodify nopeer noquery
restrict -4 default kod nomodify noper
restrict -6 default kod nomodify noper
 
# Local users may interrogate the ntp server more closely.
restrict 127.0.0.1
restrict ::1
 
# Clients from this (example!) subnet have unlimited access, but only if
# cryptographically authenticated.
#restrict 192.168.123.0 mask 255.255.255.0 notrust
 
 
# If you want to provide time to your local subnet, change the next line.
# (Again, the address is an example only.)
#broadcast 192.168.123.255
 
# If you want to listen to time broadcasts on your local subnet, de-comment the
# next lines.  Please do this only if you trust everybody on the network!
#disable auth
#broadcastclient


3、运行ntpdate命令


首先重启一下ntp服务
root@monitor:/etc#/etc/init.d/ntp restart
 
再运行
root@monitor:/etc# ntpdate -q 127.0.0.1
得到
server 127.0.0.1, stratum 3, offset -0.000003, delay 0.02565
23 Sep 17:12:00 ntpdate[11502]: adjust time server 127.0.0.1 offset -0.000003 sec


4、将其他节点133.133.10.*的时间与133.133.10.2同步


在其他每一个节点运行命令
root@slave1:~# ntpdate 133.133.10.2


这时候发现节点间的时间同步了，但ntpdate只在开机运行，我们若要设置为1小时同步一次，那么进行第5步


5、将其他节点133.133.10.*的时间定期与133.133.10.2同步


安装完以后使用crontab来自动更新时间：
#crontab -e
添加如下行：
* */1 * * * /usr/sbin/ntpdate 133.133.10.2


这行的意思是每个小时与与133.133.10.2时间同步一次。


6、通过date命令发现所有节点时间都一致了