NTP role in clustering

[Amit Manna_6]

What will be the problem if the timings of two servers in two-node cluster is not synchronized using NTP??

[Johan Lorimier]

Hi,

your systems wont have any trouble if dont use NTP, but for the safe of your applications, the time on your 2 nodes must be close. In our case we resync the time once a week with a ntp query on a real time server (using ntpdate).

Johan

[Sunil Sharma_1]

Hi,

NTP is not a must for clustering but it's recommended. If you are using Real time application it becom more imoportent.

Sunil

[Bart Paulusse]

Hi,

our cluster doesn't care about time differences between the nodes, but our SAP application does. So as said above I think it depends on the applications you're running if you need NTP or not.


regards,

Bart

[Steven E. Protter]

You don't have to but I would.

Lets say Oracle is one of the packages in the cluster. It can get whacky if the last transaction is before(in time terms) the time the database is being started.

SEP

[MArtin at unixera dot d]

For troubleshooting reasons, it is also recommended.

If you have tried stepping through the /var/adm/messages and ../../current/daemon.log and kern.log with a time skew between the systems ..... !!!

I would definately recommend setting them up with NTP, and if you do not have a timeserver or the possibility to go out on internet, you could set up the two servers the old ASE cluster way.
Let one be server and the other sync on it.

regards MArtin ..

[Thomas Bianco]

if you can't connect NTP to some outside time source, at least connect the nodes together with Peer. this will average out the time between the nodes and slew the clocks together.

#/etc/ntp.conf on NodeA
driftfile /etc/ntp/nodeA.ntp.drift
logfile /etc/ntp/nodeA.ntp.log
Peer nodeB.mynetwork.com
#server someNTPserver.outside.net


you'll be much happier with NTP running then not. there is nothing worse then forced downtime because a service thinks it's last transaction is in the future.

[John Carr_2]

while this may not be required "better safe than sorry" comes to mind and its quick to setup.

:-) John.

[hpuxrox]

If it is a production cluster, I would not run without it. There are a lot of issues that can arise from the package switching to a time that is less than the time it came from. Although, you can find many "ifs" and "buts" for why not to do things... But, that ressioning is not a very good production mindset.