主服务：hadoop1 ip:192.168.1.88 其他服务器：hadoopxx ip：192.168.1.xx 1)查看软件包是否安装 rpm -q ntp
1.png 2)如果没有 那么用yum install 软件包 进行安装 3)设置开启自启动 systemctl enable ntpd 4)启动服务 systemctl start ntpd 5)设置主服务器 配置文件 标记处为修改内容 vi /etc/ntp.conf # For more information about this file, see the man pages # ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5). driftfile /var/lib/ntp/drift # Permit time synchronization with our time source, but do not # permit the source to query or modify the service on this system. restrict default nomodify notrap nopeer noquery # Permit all access over the loopback interface. This could # be tightened as well, but to do so would effect some of # the administrative functions. restrict 127.0.0.1 restrict ::1 # Hosts on local network are less restricted. #restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap #111111111111 restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap # Use public servers from the pool.ntp.org project. # Please consider joining the pool (http://www.pool.ntp.org/join.html). #server 0.centos.pool.ntp.org iburst #server 1.centos.pool.ntp.org iburst #server 2.centos.pool.ntp.org iburst #server 3.centos.pool.ntp.org iburst #111111111111 server 2.cn.pool.ntp.org server 1.asia.pool.ntp.org server 2.asia.pool.ntp.org #broadcast 192.168.1.255 autokey # broadcast server #broadcastclient # broadcast client #broadcast 224.0.1.1 autokey # multicast server #multicastclient 224.0.1.1 # multicast client #manycastserver 239.255.254.254 # manycast server #manycastclient 239.255.254.254 autokey # manycast client #111111111111 restrict 2.cn.pool.ntp.org nomodify notrap noquery restrict 1.asia.pool.ntp.org nomodify notrap noquery restrict 2.asia.pool.ntp.org nomodify notrap noquery server 127.0.0.1 # local clock fudge 127.0.0.1 stratum 10 # Enable public key cryptography. #crypto includefile /etc/ntp/crypto/pw # Key file containing the keys and key identifiers used when operating # with symmetric key cryptography. keys /etc/ntp/keys # Specify the key identifiers which are trusted. #trustedkey 4 8 42 # Specify the key identifier to use with the ntpdc utility. #requestkey 8 # Specify the key identifier to use with the ntpq utility. #controlkey 8 # Enable writing of statistics records. #statistics clockstats cryptostats loopstats peerstats # Disable the monitoring facility to prevent amplification attacks using ntpdc # monlist command when default restrict does not include the noquery flag. See # CVE-2013-5211 for more details. # Note: Monitoring will not be disabled with the limited restriction flag. disable monitor 6)重启服务 systemctl restart ntpd 7)执行 ntpstat 如果显示下边结果 正在启动 unsynchronised time server re-starting polling server every 64 s 8)执行 ntpstat 如果显示下边结果 已经开始运行 synchronised to NTP server (182.92.12.11) at stratum 3 time correct to within 17 ms polling server every 64 s 9)修改非主服务器配置文件 标记处为修改内容 vi /etc/ # For more information about this file, see the man pages # ntp.conf(5), ntp_acc(5), ntp_auth(5), ntp_clock(5), ntp_misc(5), ntp_mon(5). driftfile /var/lib/ntp/drift # Permit time synchronization with our time source, but do not # permit the source to query or modify the service on this system. restrict default nomodify notrap nopeer noquery # Permit all access over the loopback interface. This could # be tightened as well, but to do so would effect some of # the administrative functions. restrict 127.0.0.1 restrict ::1 # Hosts on local network are less restricted. #restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap # Use public servers from the pool.ntp.org project. # Please consider joining the pool (http://www.pool.ntp.org/join.html). #server 0.centos.pool.ntp.org iburst #server 1.centos.pool.ntp.org iburst #server 2.centos.pool.ntp.org iburst #server 3.centos.pool.ntp.org iburst #1111111111 server 192.168.1.88 restrict 192.168.1.88 nomodify notrap noquery server 127.0.0.1 fudge 127.0.0.1 stratum 10 #broadcast 192.168.1.255 autokey # broadcast server #broadcastclient # broadcast client #broadcast 224.0.1.1 autokey # multicast server #multicastclient 224.0.1.1 # multicast client #manycastserver 239.255.254.254 # manycast server #manycastclient 239.255.254.254 autokey # manycast client # Enable public key cryptography. #crypto includefile /etc/ntp/crypto/pw # Key file containing the keys and key identifiers used when operating # with symmetric key cryptography. keys /etc/ntp/keys # Specify the key identifiers which are trusted. #trustedkey 4 8 42 # Specify the key identifier to use with the ntpdc utility. #requestkey 8 # Specify the key identifier to use with the ntpq utility. #controlkey 8 # Enable writing of statistics records. #statistics clockstats cryptostats loopstats peerstats # Disable the monitoring facility to prevent amplification attacks using ntpdc # monlist command when default restrict does not include the noquery flag. See # CVE-2013-5211 for more details. # Note: Monitoring will not be disabled with the limited restriction flag. disable monitor 10)查看同步情况 ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== *hadoop1 182.92.12.11 3 u 71 128 377 0.209 -1.088 0.367 localhost .INIT. 16 l - 1024 0 0.000 0.000 0.000 参数解释： ● remote： 远程NTP服务器的IP地址或域名，带 “*” 的表示本地NTP服务器与该服务器同步。 ● refid： 远程NTP服务器的上层服务器的IP地址或域名。 ● st： 远程NTP服务器所在的层数。 ● t： 本地NTP服务器与远程NTP服务器的通信方式，u: 单播； b: 广播； l: 本地。 ● when： 上一次校正时间与现在时间的差值。！！！！！！！！！！！！！ ● poll： 本地NTP服务器查询远程NTP服务器的时间间隔。！！！！！！！！！！！ ● reach： 是一种衡量前8次查询是否成功的位掩码值，377表示都成功，0表示不成功。 ● delay： 网络延时，单位是10的-6次方秒。 ● offset： 本地NTP服务器与远程NTP服务器的时间偏移。 ● jitter： 查询偏差的分布值，用于表示远程NTP服务器的网络延时是否稳定，单位为10的-6次方秒。 11)测试 a. 暂时关闭ntp timedatectl set-ntp 0 //不然会报错 Failed to set time: Automatic time synchronization is enabled b. 设置服务器时间 timedatectl set-time '2018-08-08' c.打开ntp服务 timedatectl set-ntp 1 d.查看系统时间 date 一会儿就不是'2018-08-08'了 证明已经同步了
