cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From K F <kf200...@yahoo.com>
Subject Re: ntpd clock sync
Date Wed, 09 Mar 2016 17:03:22 GMT
the clock is about 30 to 40 seconds behind.

      From: Jack Krupansky <jack.krupansky@gmail.com>
 To: user@cassandra.apache.org 
 Sent: Wednesday, March 9, 2016 11:31 AM
 Subject: Re: ntpd clock sync
   
How far out of sync are the nodes? A few minutes or less? Many hours?
Worst case, you could simply take the entire cluster down until that future time has passed
and then bring it back up.

-- Jack Krupansky
On Wed, Mar 9, 2016 at 11:27 AM, Jeff Jirsa <jeff.jirsa@crowdstrike.com> wrote:

If you don’t overwrite or delete data, it’s not a concern.If the clocks show a time in
the past instead of in the future, it’s not a concern.
If the clock has drifted significantly into the future, when you start NTP you may be writing
data with timestamps lower than timestamps on data that already exists. In this case, the
existing data (with timestamps in the future) may take precedence over new writes (with correct
timestamps).


From:  K F
Reply-To:  "user@cassandra.apache.org", K F
Date:  Wednesday, March 9, 2016 at 8:23 AM
To:  User
Subject:  ntpd clock sync

Hi,
I have question about ntpd. In certain clusters where new datacenters were added since 1 week
we stood-up those machines didn't have ntpd running on them. Will it cause any problem if
we enable or start ntpd now on those newly added datacenters. 
Thanks.



  
Mime
View raw message