ServiceGuard: relocatable app IP address on a specific LAN

[Brent Barton]

All,

We are trying to implement a MCSG 2 node cluster for several applications. For a temporary solution we want to use an unconfigured LAN interface and have it assume the package IP when the package is on that node. I understand that this isn't best practice and that it a SPOF from the LAN perspective, but again it is temporary.

We are doing this so that we do not have to modify several programs to bind to the relocatable IP address or change firewall rules and routing. It is stated that this can be done in the Managing ServiceGuard manual on page 376.

"If the application cannot be modified as recommended above, a
workaround to this problem is to not use the stationary IP address at all,
and only use a single relocatable application IP address on a given LAN
card. Limitations with this workaround are as follows:
• Local LAN failover will not work.
• There has to be an idle LAN card on each backup node that is used to
relocate the relocatable application IP address in case of a failure."


Do I need to configure the interface, then ifconfig it down in the customer defined startup or will ServiceGuard do this automatically for me? Any help is appreciated

Thanks,

B

[Steven E. Protter · Accepted solution]

Service guard has specific instructions on how to implement a standby lan card with the same ip address (but down, ready to go) as the main ip address in the main lan.

This increases reliability,availability but is not package failover.

Sorry I can't be more specific, but one of these docs has the configuration instructions:

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B3936-90079/B3936-90079_top.html&con=/hpux/onlinedocs/B3936-90079/00/00/96-con.html&toc=/hpux/onlinedocs/B3936-90079/00/00/96-toc.html&searchterms=lan%7cfailover%7cServiceGuard&queryid=20041020-223247


http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/5990-8153/5990-8153_top.html&con=/hpux/onlinedocs/5990-8153/00/00/74-con.html&toc=/hpux/onlinedocs/5990-8153/00/00/74-toc.html&searchterms=lan%7cfailover%7cServiceGuard&queryid=20041020-223247

http://docs.hp.com/hpux/onlinedocs/5567/Optimizingfailover_6-22.pdf

I've ordered the documents in what I think is the best order based on title and summary to give you the information you need.

SEP

[Sridhar Bhaskarla]

Hi Brent,

I don't know under what context that information was given in the serviceguard manual. I don't have one handy at this time.

When package comes up, the floating address is assigned via 'cmmodnet' command. cmmodnet command looks for an already existing subnet to which the relocatable IP will be assigned. In order for you to have a subnet, there should have already been an interface with an IP address with an appropriate subnet mask.

So, I am not sure how serviceguard can manage an interface with relocatable IP address alone. I think it is about the application listening at a port bound to only relocatable IP address rather than "ANY" interface like *. as seen in your netstat -an output.

-Sri