Using Availability Manager on Windows to adjust VMScluster quorum

[Clyde 10]

Please confirm following Availability Manager setup will work for adjusting quorum:

- OpenVMS IA64 cluster with collector on each node
- Windows 2003 server num1 on same level 2 LAN as cluster nodes, with server and analyzer installed.
- Windows 2003 server num2 on different IP segment, as cluster nodes, with analyzer installed.

Users could use either either Windows 2003 server num1 or num2 to adjust quorum.

Using num1 the analyzer would communicate using AMDS protocol to cluster node to adjust quorum.

Using num2 the analyzer would communicate to num1 running server, which would then communicate to cluster node to adjust quorum.

Thanks.

[Andy Bustamante]

See http://h71000.www7.hp.com/openvms/products/availman/docs.html and http://h71000.www7.hp.com/openvms/products/availman/6552install.pdf specifically. This a valid configuration; however I see one potential issue. The documentation states Windows 2000 or Windows XP.

I don't see Windows Server 2003 listed as a supported operating system. I used to run AM on a Windows Server 2000 system and connect via VPN. I'd expect this to just work, but it may not be supported.

You're also allowing users make fixes from more than one management station. I would expect VMS to handle this gracefully, but would probably set up a single access point of access for users (sound like your Num2 system) as the point of access.

Andy

[Steve Reece_3]

I'd be cautious before saying that the system on another LAN segment (presumably another subnet?) will work. Last I read (which is some time ago I'll admit) the protocols involved with Availability Manager weren't routable so you needed the machines to be on the same subnet or it wouldn't work.

This makes a degree of sense when you consider what happens with an inquorate cluster - all user processing stops and waits for the cluster to become quorate again. This includes all the TCP/IP stack processes. AvailMan needs to go in at driver level to intervene so can't rely on the TCP/IP stack to get itself out of the situation it's in.

I've not seen any documentation suggesting that AvailMan nodes can forward on fixes to other nodes which is what's being suggested in using num2 analyser to communicate with num1 running server to communicate with the cluster.

Maybe a better way would be to use num2 to remote desktop to num1 server and do the fixes to quorum from the num1 server?
Steve

[Hoff]

This question is sufficiently odd that there's almost certainly (far?) more here than is currently known.

The immediate response (and which is sufficiently obvious that there's probably something here preventing its use) VPN into the LAN and RDP or VNC the Windows box and be done with it.

I'ld not look to extend management outside the OpenVMS LAN segment. Regardless of whether it's feasible, or whether the TLS works here.

And yes, then there's the whole what-runs-on-what question with Windows. Try it. Let us know. The data server forwarding (yesh; yet another platform-specific and client-server protocol in VMS) is intended to provide this.

Why is the question odd? Beyond the sequencing and the Windows stuff, that if you even need to do this quorum reset, then this cluster is in need of some work or mayhap a quorum node. I'm going to guess either a misconfigured cluster, or a two-node configuration. Details on that would be interesting, too.

[MichelleP_1]

Steve, WAN support was added in Availability Manager V3.0-2. It adds a 3rd component, the "Data Server" that is run on a system in the same LAN as the hosts running the Data Collector. Then Data Analyzer can connect to a Data Server over the WAN.

I've been using this version (well, the 3.0-1 & 3.0-2 beta versions) for at least year and 1/2, but fortunately haven't had to do any "fixes" over the WAN, especially not quorum adjustment.

Clyde, your configuration sounds right to me(without getting into what Andy pointed out re: Windows versions, but I wouldn't expect an issue there). As Hoff suggests, give it a try. You could try one of the other "fixes", like adjusting a quota on a process, and watch the Data Server log.

I was thrilled when they added the WAN support. In many environments the system manager does not have direct access to a Windows system that is on the same LAN as the VMS systems. This allows the system manager to run the analyzer on their desktop. Personally, I run the Data Server on a VMS system management node.

[Bart Zorn_1]

I have been running the beta versions of AM 3.0. The Server on a DS15 which sits on a dedicated vlan for all the OpenVMS nodes, and the analyzer either on a DS15 workstation or a Windows XP laptop far away from the datacenters. I have done many fixes this way, including adjusting process quota, killing runaway processes and adjusting cluster quorum.

Great tool!

Unfortunately, I lost my contract before V3.02 came out.

Regards,

Bart

[Shubhabrata Bose · Accepted solution]

Hi Clyde_10,

Here are my inputs:
- OpenVMS IA64 cluster with collector on each node
- Windows 2003 server num1 on same level 2 LAN as cluster nodes, with server and analyzer installed.
- Windows 2003 server num2 on different IP segment, as cluster nodes, with analyzer installed.

Users could use either either Windows 2003 server num1 or num2 to adjust quorum.
>>> Quorum adjustment is possible for the kit that will be acting as Analyzer for example, "num2" in tis case,because only analyzer contains the GUI screens for adjusting the quorums.Whereas the Server runs only as a terminal.

Thanks,
Shubh,
AM Engineering,

[Peter Zeiszler]

I would definitely make sure to control WHO can login to Num1 and Num2 so that you don't get mysterious quorum adjustments.

[MichelleP_1]

With the server running, one could run the analyzer on any workstation (provided they had the proper key), not just your two Windows servers. So (as I'm sure you have anyway) make sure you use the combination of keys and the Data Collector password to provide or restrict Read/Write and Read-only access.

[Clyde 10]

I wish to clarify my environment, and needs a little more here...

- OpenVMS IA64 dual site cluster with two IA64 nodes at each site, with voting set up as follows:
Site A (secondary site) - each node has one vote each
Site B (Primary site) - one node has one vote, one node has TWO votes
Expected votes = 5
Quorum calc (exp votes + 2)/3 = 3
Scenarios:
- site B will run when sites can not reach each other, and A will hang. Load will run at B, without intervention.
- Site B will run if A is down. Load will run at B, without intervention.
- site A will hang if B is down. NEED INTERVENTION HERE. <----

Other than the OpenVMS cluster, there are no other OpenVMS servers to rely on, to use for Availability Manager. So supported
Windows solutions/capabilities have to be explored and weighed to decide on go-forward solution, to bring up Site A under duress.

Each OpenVMS node will run Availability Manager collector on each node.

Method 1:
- Windows server num1 on same level 2 LAN as cluster nodes, with Availability Manager Server and Availability Manager Analyzer installed.
User would log into Windows server num1, and go into the Analyzer. User could then adjust quorum on the cluster, since the analyzer would
communicate with the OpenVMS node collector code directly.

Method 2:
- Windows server num2 on different IP segment, (not level 2 bridged to same network as cluster nodes), with only Availability Analyzer
installed. User would log into windows
server num2, go into analyzer, which would communicate to the server process on windows server num1, and then be able to adjust quorum
on the cluster. The details of this assumption are that the command to adjust quourum is entered on the analyzer GUI, gets passed via tcpip
transport to the server process on windows server num1, and then is passed to the Availability Manager code running on the cluster in
order to free the cluster at site A to run.

Users could use either either Windows 2003 server num1 or num2 to adjust quorum.

I believe what was stated here, says it will work. The version of windows to use is fuzzy, and I need to get official confirm/blessing of
2003 or 2008 support.

Thanks to all.