| |
|
RSS Feed - WebSphere MQ Support
|
RSS Feed - Message Broker Support
|
  |
|
| Not directly MQ - Time Syncing your servers |
« View previous topic :: View next topic » |
| Author |
Message
|
| PeterPotkay |
 Posted: Tue Jun 22, 2004 1:17 pm Post subject: Not directly MQ - Time Syncing your servers |
 |
|
Poobah
Joined: 15 May 2001
Posts: 7722
|
What do people out there use for syncing up all their clocks on all their servers?
We are using Transaction Vision to correlate our transactions. TV reports the time from its sensors down to the millisecond (microsecond on z/OS and UNIX). But if the servers are off in time by tenths or even hundredths of a second, the result are skewed for transactions that zip thru 3 servers in half a second. I get results showing that events on server 3 happened before server 2. And I am not confident on how long the message took to get from 1 to 2, even if the order happens to be correct.
Is it realistic to expect better than one second accuracy between servers if you are using time sync software? To the naked eye all the servers look pretty well synced up, but at the millisecond level, they are all over the place.
_________________
Peter Potkay
Keep Calm and MQ On |
|
| Back to top |
|
 |
| kirani |
| Posted: Tue Jun 22, 2004 2:51 pm Post subject: |
|
|
Jedi Knight
Joined: 05 Sep 2001
Posts: 3779
Location: Torrance, CA, USA
|
I thought we don’t need to sync clocks for Transaction Vision. That's what the Sales person from Bristol told us! Soon we are going to do a POC for Transaction Vision in our environment. I guess, I need to rework on my decision analysis matrix.
_________________
Kiran
IBM Cert. Solution Designer & System Administrator - WBIMB V5
IBM Cert. Solutions Expert - WMQI
IBM Cert. Specialist - WMQI, MQSeries
IBM Cert. Developer - MQSeries
|
|
| Back to top |
|
|
| RogerLacroix |
| Posted: Tue Jun 22, 2004 7:27 pm Post subject: |
|
|
Jedi Knight
Joined: 15 May 2001
Posts: 3264
Location: London, ON Canada
|
Hi,
At my current client site, they have a pair of time servers that get the time from an atomic clock. Then on the Solaris servers we run ntpd daemon to set the clock from the 2 internal time servers. On the Windows 2000 Servers, they have a ntp program (I don't remember the name but I will ask tomorrow) running to set the clock from the 2 internal time servers.
The mainframe is off by 10 seconds and it is a know fact, so we just factor it into the equation (no ntp program running!!).
Regards,
Roger
_________________
Capitalware: Transforming tomorrow into today.
Connected to MQ!
Twitter |
|
| Back to top |
|
|
| PeterPotkay |
| Posted: Wed Jun 23, 2004 4:09 am Post subject: |
|
|
Poobah
Joined: 15 May 2001
Posts: 7722
|
Roger, do you know to what level the time syncing software you use guarantees? Is it just to the second, or the tenth, hundredth, etc?
Synced up to the second may be fine for the human eye, but could be wildly off at the millisecond level. I am just wondering if time sync software for Windows servers and Solaris servers is considred good enough if it goes down to the second, and I am being unreasonable wanting all my server clocks to be better than that.
_________________
Peter Potkay
Keep Calm and MQ On |
|
| Back to top |
|
|
| jefflowrey |
| Posted: Wed Jun 23, 2004 5:01 am Post subject: |
|
|
Grand Poobah
Joined: 16 Oct 2002
Posts: 19981
|
Peter -
Anything that claims to be an NTP service should implement RFC1305.
Accuracies are dependant in some respects on hardware... but most machines should be syncable within about 128 milliseconds.
try 'man ntpd' on your Solaris box.
_________________
I am *not* the model of the modern major general. |
|
| Back to top |
|
|
|
|
|
| |
|
Page 1 of 1 |
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
|
|
|
