Different subnet s- which solution?

[Madej]

Hi

I have one server and one XP1024 on first side with IP address 10.9.X.X netmask 255.255.0.0, and another server with XP128 storage on second side with IP 10.10.X.X and netmask 255.255.0.0. XP storages have CA.
I want to configure my application as HA with some cluster solution - MC/ServiceGuard, ContinentalCluster?.
Which solution will makes me happy ;-) ?

Thanks for reply

[Steven E. Protter]

Shalom,

MC/Serviceguard works with a common shared storage device. If the systems are not physically separated, they can be connected to storage.

For networking, will probably need to have a common network structure between the two on secondary NIC cards.

Continental Clustering is designed for systems that are physically separate. It may help in this circumstance.

As to which solution will make you happy? I assume the one that works, which is unclear without more information from you. Beyond that is a philosophical question which is beyond the scope of this lecture.

SEP

[Stephen Doud]

Without much fanfare, a new feature was released for Serviceguard via patch PHSS_37094 for A.11.18 @ hpux 11.23
The new feature provides for cross-subnet nodes and packages.

The patch text reads:

This patch delivers the following enhancements to Serviceguard:
Cross-subnet support in Serviceguard provides the ability to configure a single Serviceguard cluster across distinct subnets on HP-UX.
This includes:
1. Routed Heartbeat networks i.e Heartbeating across routed subnets
2. Automatic fail over a package between distinct subnets
For further details on each of the enhancements, refer to the Serviceguard A.11.18 Release Notes December 2007 Reprint. User action is required in order to make use of each of these enhancements and they are not enabled automatically.

The re-released A.11.18 Release Notes are here:
http://docs.hp.com/en/B3935-90114/B3935-90114.pdf

The cross-subnet discussion begins on page 40.


PHSS_37244 is the equivalent patch for A.11.18 @ hp-ux 11.31

[Rita C Workman]

Madej,

Are your server/storage units at different sites? Or are they at the same site?

Continental Cluster is the high end product for failing from site-2-site. You would have to replicate your storage/data between your two XP units. CA (Continuace Access) may be the product for doing that. And as was pointed out you'll have to network up the sites to tranfer the data between your storage units.
Generally you would have different subnets between your sites. But you have to address the resolution issue (i.e. hostfile or DNS) to ensure that clients are able to continue to connect in the event of site failover. This is basically high end DR for Service Guard and requires a good bit of planning and configuring to set up.

MC/SG allows for failing over from server-2-server within the same location. As Stephen pointed out, the newer versions allow different subnets. As Steven Protter mentions for this, you must have both servers able to see the same disk. This version of MC/SG is the base product and requires a good bit of planning and configuring. But you might say it's half of what Continental Cluster would take.

So....is all your hardware together, or are you seperated between sites?

Rgrds,
Rita