Time synchronization in Alpha OpenVMS Cluster

[Feige]

Dear all,

I setup a cluster system,node name is A(IP 192.168.1.1) and B(IP 192.168.1.2). Now I want to use NTP service to implment time synchronization between them and A is time source.

For Node A, I enable NTP service and configure SYS$SPECIFIC:[TCPIP$NTP]TCPIP$NTP.CONF:
Peer 127.0.0.1
and then start NTP.

For Node B, I also enable NTP service and configure SYS$SPECIFIC:[TCPIP$NTP]TCPIP$NTP.CONF:
Peer 192.168.1.1
and then start NTP.

Otherwise I found problem that the time difference between them is always 15seconds.
what's wrong?

Thanks in advance.

[Heinz W Genhart]

Hi Feige

We started a discussion about same stuff some days ago. Could you have a look at http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1219839

Regards

Geni

[Feige]

Hi,Geni,

Thanks your quick response!

I read your reference, unfortunately,I can't find the answer.Could you please help me? it's very urgent for me. Thanks a lot!

[Feige]

Dear Geni,

Sorry,I don't forget to say that there are no external time source and also can't connect tto internet. there is just production LAN. so I want to set node A as time source, and A synchronize B and other nodes.

How to do? Thanks again

[Duncan Morris]

Feige,

see this note from Hoff

http://www.openvms.compaq.com/wizard/wiz_0104.html

about setting a VMS node as an NTP server.


Duncan

[Duncan Morris]

Feige,

you could also skip using NTP totally, since you simply want node A to be the definitive time source.

Why not just issue

$ SET TIME/CLUSTER

from node A on a regular basis (batch job or scheduler)?

See the HELP SET TIME /CLUSTER entry


Duncan

[Ian Miller.]

One issue with using SET TIME/CLUSTER is that it is possible for the time on another node to be set back e.g if node B has time slightly ahead of node A then doing SET TIME/CLUSTER on node A will set time the time on node B back to that of node A. Some software does not like the time going back.

Using NTP gives a consistent time across all your nodes.

[Feige]

Thanks a lot. I still have question:

server 127.127.1.0 prefer
fudge 127.127.1.0 stratum 0

in our system,node A has host names:
192.168.1.1 A
127.0.0.1 localhost

It means that I should change "127.127.1.0" to "127.0.0.1" or "192.168.1.1" or not?
Thanks!

[Art Wiens]

I guess back in Oct-1999 the Wizard was having "a bad day" and typo'd when giving the example for using the localhost's IP address. ;-)

Yes 127.0.0.1 should be used.

Cheers,
Art

ps. Technically you could build a 127.127.1.x network if, as you say, it's a private LAN and the systems don't need to go anywhere.

[Feige]

Hi, Art

Thanks!

I found that a description "In these statements, the hardware address of the local clock (LOCAL) is 127.127.1.0. These statements force NTP to use its own system clock as a reference clock." in a documents "HP TCPIP Services for OpenVMS Management.pdf".

127.0.0.1 is the localhost IP address,so

peer 127.0.0.1
is also right?