topic Re: Primary and Standby Heartbeat IP in Operating System - HP-UX

Primary and Standby Heartbeat IP

Jason Ng Teng Po — Mon, 16 Mar 2009 05:17:34 GMT

Hi Guys,

I'm going to implement MCSG on 2 node.

For both primary and standby heartbeat IP, can both be on the same segment? See example below.

Node1
Primary HB: 192.168.1.1
Standby HB: 192.168.1.2

Node2
Primary HB: 192.168.1.3
Standby HB: 192.168.1.4

Are they any impact on this if I implement it this way?

Re: Primary and Standby Heartbeat IP

Johnson Punniyalingam — Mon, 16 Mar 2009 05:29:58 GMT

Hi Jason,

Would recommend to take look below link

Understanding and Designing Serviceguard Disaster Tolerant Architectures, 1st Edition, December 2006 HP-UX 11i v1, 11i v2 [ PDF ] [ HTML ]

Understanding and Designing Serviceguard Disaster Tolerant Architectures, 3rd Edition, December 2007 HP-UX 11i v1, 11i v2, 11i v3 [ PDF ] [ HTML ]

http://docs.hp.com/en/ha.html#Serviceguard

Thanks,
JOhnson

Re: Primary and Standby Heartbeat IP

Jason Ng Teng Po — Mon, 16 Mar 2009 06:26:55 GMT

I cannot find my answer in there.

Re: Primary and Standby Heartbeat IP

Johnson Punniyalingam — Mon, 16 Mar 2009 07:31:38 GMT

Hi Jason,

Check below link

https://forums11.itrc.hp.com/service/forums/questionanswer.do?admit=109447626+1237191979480+28353475&threadId=122662

Some info on configuring lan card

http://docs.hp.com/hpux/onlinedocs/B3936-90024/B3936-90024.html

and HA FAQ..

http://us-support.external.hp.com/iv/bin/doc.pl/sid=cc4d5bf606752687a6/screen=ivH
ome/?NODEID=English_SHW::WW_SW_UX_RCFAQ_EN_E/Q1.2&WARP=1

Thanks,
Johnson

Re: Primary and Standby Heartbeat IP

Johnson Punniyalingam — Mon, 16 Mar 2009 07:32:58 GMT

As long as the second nic is defined as the failover lan card, the primary IP will be bound to that NIC card upon failover. You can support multiple IP's on the same NIC but they have to be in the same subnet for that to work.

Port aggregation & teaming software could work for you as well.

By the way don't forget to put heartbeat's on each segment that is defined on your cluster. It helps with keeping up the pings.

Thanks,
Johnson

Re: Primary and Standby Heartbeat IP

B. Hulst — Mon, 16 Mar 2009 07:36:59 GMT

They can be on the same segment but it is better to have them as two distinct networks.

If you switch fails with the 192.168.1.x network on it your whole cluster is down.
No failover to the other NIC.

Advice:
two networks
two physical switches.

Re: Primary and Standby Heartbeat IP

Jason Ng Teng Po — Mon, 16 Mar 2009 07:41:54 GMT

Thanks Thanks

BTW I won't be using switches for my heartbeat. I'm going to use cross-cables

Re: Primary and Standby Heartbeat IP

Matti_Kurkela — Mon, 16 Mar 2009 07:54:35 GMT

1.) HP-UX in general gets very confused if you configure two separate NICs to use two IP addresses within the same network segment. This configuration is not supported. (It can be made to work, but this configuration can be unpredictable in failure situations. Not recommended for a HA environment.)

2.) If your heartbeat goes through only one segment, there may be a Single Point of Failure: even one failed NIC sending a constant stream of garbage packets can block the entire segment, unless your network switches are smart enough to isolate a NIC with this type of fault on their own.

Two heartbeat IP segments are obviously better than one. But if you can have only one, you might want to use APA or ServiceGuard's Local LAN Failover on the heartbeat NICs.

With APA, you can join two NICs into an active/active "team", so both NICs are used for heartbeats, even though there is only one heartbeat IP address per node.

With SG's Local LAN Failover, the pair of NICs must be in active/passive configuration, so only one NIC at a time is used. The other one will be idle until the first NIC loses its network link or can otherwise be detected as failed. At that point, the IP address of the first NIC will be switched over to the second NIC.

In configurations like this, if your heartbeat NICs are not all connected to a single switch (to avoid a single point of failure), you should test the failover very carefully when setting up the cluster, e.g. by disconnecting one LAN cable at a time and verifying the nodes can still reach each other.
The most challenging test is probably when Node1's active HB NIC is connected to switch A, Node2's active HB NIC is connected to switch B and the interconnection between the switches is lost.

MK

Re: Primary and Standby Heartbeat IP

Jason Ng Teng Po — Mon, 16 Mar 2009 09:35:59 GMT

So I should put it like this?

Node1
Primary HB: 192.168.1.1
Standby HB: 10.0.0.1

Node2
Primary HB: 192.168.1.2
Standby HB: 10.0.0.2

Re: Primary and Standby Heartbeat IP

B. Hulst — Wed, 18 Mar 2009 08:59:40 GMT

Yes.