Re: RAC nodes and date/time sync

mea0730 wrote:
> Well I asked Oracle! They said "exact" clock sync is not important.
> The only thing that will happen is that if a node is more than 15
> minutes out of sync it will get evicted. They did recommend running a
> network time sync to keep them from getting too far out of sync.
>
> Mike

I just ran a test with 10gR2 and the eject time-out is about 10 sec. Who-ever told you 15 minutes is out to lunch: And should stay there.

Let me give you a very simple, non Oracle, answer to the question of why time synchronization is essential.

Lets assume you have a problem and need to go searching through log files to figure out what went wrong? If you don't have time-sync between all nodes, all app servers, all web servers, and all switches how are you going to determine what went wrong first and what events it triggered?

Are you really going to juggle in your head that the event that occurred 20 seconds later according to the log file on node 1 actually happened before the event in the log file on node 2? And why?

It takes almost no effort at all with either Mac or Linux to set up a time-server. Certainly less than 5 minutes.

-- 
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)