Time Sync Issue


#1

Hello,

Good day to everyone .
I got time sync issue recently by linux command “/usr/sbin/ntpdate tw.pool.ntp.org”.
Here are some details :
From root@twtpelpssdb01t Wed Apr 5 19:00:02 2017
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Message-Id: 201704051100.v35B02cc030984@twtpelpssdb01t
From: root@twtpelpssdb01t (Cron Daemon)
To: root@twtpelpssdb01t
Subject: Cron root@twtpelpssdb01t /usr/sbin/ntpdate tw.pool.ntp.org
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X-Cron-Env: <SHELL=/bin/sh>
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X-Cron-Env: <PATH=/usr/bin:/bin>
X-Cron-Env: <LOGNAME=root>
X-Cron-Env: <USER=root>

5 Apr 19:00:02 ntpdate[30982]: adjust time server 61.216.153.104 offset -0.006269 sec

From root@twtpelpssdb01t Wed Apr 5 20:00:05 2017
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Date: Wed, 5 Apr 2017 20:00:05 +0800
Message-Id: 201704051200.v35C05j7002966@twtpelpssdb01t
From: root@twtpelpssdb01t (Cron Daemon)
To: root@twtpelpssdb01t
Subject: Cron root@twtpelpssdb01t /usr/sbin/ntpdate tw.pool.ntp.org
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Auto-Submitted: auto-generated
X-Cron-Env: <SHELL=/bin/sh>
X-Cron-Env: <HOME=/root>
X-Cron-Env: <PATH=/usr/bin:/bin>
X-Cron-Env: <LOGNAME=root>
X-Cron-Env: <USER=root>

5 Apr 20:00:05 ntpdate[2931]: step time server 61.216.153.105 offset 2678399.804672 sec

From root@twtpelpssdb01t Wed Apr 5 20:00:09 2017
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Date: Wed, 5 Apr 2017 20:00:09 +0800
Message-Id: 201704051200.v35C09uQ003057@twtpelpssdb01t
From: root@twtpelpssdb01t (Cron Daemon)
To: root@twtpelpssdb01t
Subject: Cron root@twtpelpssdb01t /usr/sbin/ntpdate tw.pool.ntp.org
Content-Type: text/plain; charset=UTF-8
Auto-Submitted: auto-generated
X-Cron-Env: <SHELL=/bin/sh>
X-Cron-Env: <HOME=/root>
X-Cron-Env: <PATH=/usr/bin:/bin>
X-Cron-Env: <LOGNAME=root>
X-Cron-Env: <USER=root>

5 Apr 20:00:09 ntpdate[3011]: adjust time server 61.216.153.105 offset -0.000601 sec

Any idea ???

Best Regards,
Stevenstrong text


#2

you shouldn’t use cronjob ntpdate for time adjust, use ntpd instead


#3

Use ntpdate (with multiple servers) ONCE and the start ntpd (also, with multiple servers). ntpdate will make the clock jump backwards, which is a bad thing.


#4

Sadly there are still some outdated instruction teaching beginners to use cron+ntpdate to keep the time, like the vbird article (in Chinese).


#5

Actually, we used ntp daemon to sync time for our RAC envs,but still got big differences among RAC nodes. And then we adapted to use ntp command. I am wondering why you said “sad”. Post my comments here is to check anything wrong with the server pools. If you are not the owner, just save your words.

-------- 原始訊息 --------自: CS Chen ntppool@discoursemail.com 日期: 2017/4/6 21:52 (GMT+08:00) 至: stevenchang1213@gmail.com 主旨: [NTP Pool Project] [Server operators] Time Sync Issue

          alica
          

          April 6
        
      
    
  


  Sadly there are still some outdated instruction teaching beginners to use cron+ntpdate to keep the time, like the vbird article (in Chinese).

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#6

Hi Steven

I am this server operators (61.216.153.104, 61.216.153.105), i don’t know why you has big time differences. if use ntp daemon still has this problem, maybe check your environment first.

my ntp upstream from stdtime.gov.tw

server tick.stdtime.gov.tw iburst
server tock.stdtime.gov.tw iburst
server clock.stdtime.gov.tw iburst
server watch.stdtime.gov.tw iburst
server time.stdtime.gov.tw iburst

Howto use pool.ntp.org
http://www.pool.ntp.org/zh/use.html


#7

Roger

從我的 Samsung Galaxy 智慧型手機傳送。
-------- 原始訊息 --------自: Randy Wong ntppool@discoursemail.com 日期: 2017/4/7 00:49 (GMT+08:00) 至: stevenchang1213@gmail.com 主旨: [NTP Pool Project] [Server operators] Time Sync Issue

          randy
          

          April 6

Hi Steven

I am this server operators (61.216.153.104, 61.216.153.105), i don’t know why you has big time differences. if use ntp daemon still has this problem, maybe check your environment first.

my ntp upstream from stdtime.gov.tw

server tick.stdtime.gov.tw iburst
server tock.stdtime.gov.tw iburst
server clock.stdtime.gov.tw iburst
server watch.stdtime.gov.tw iburst
server time.stdtime.gov.tw iburst

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#8

Hello Ralf,

            tw.pool.ntp.org is already a server pool .
            Here is my debugging output :

[root@twtpelpssdb01t ~]# ntpdate -q tw.pool.ntp.org
server 61.216.153.107, stratum 3, offset 0.001884, delay 0.03125
server 103.18.128.60, stratum 2, offset 0.002737, delay 0.02943
server 61.216.153.104, stratum 3, offset 0.001884, delay 0.02963
7 Apr 09:55:02 ntpdate[6302]: adjust time server 103.18.128.60 offset
0.002737 sec

  Anyway thanks for your paying attention on my post.

BR,
Steven


#9

Hello mengzhuo https://community.ntppool.org/users/mengzhuo,

  I know nptd is a better way to sync time, but sometimes it's not

technical issue.
OK…
I will use the following command for debugging further.
/usr/sbin/ntpdate -dB 10.36.15.1 watch.stdtime.gov.tw tock.stdtime.gov.tw
10.36.1.2
Actually, I doubt the hardware issue, because only this RAC group got
probjlems.
For god sake, I just do my jobs.
Thanks for your paying attentions.

BR,
Steven