[Linux-cluster] sharing same ip with 2 services on two nodes

[Gordan Bobic]

Right, I see what you mean now. No, you can't do that - the service always
has to run on the node where it's IP is. But you can fail over the whole
resource group (IP + services) together if required.

Gordan

On Fri, 17 Apr 2009 14:01:05 +0200, ESGLinux <esggrupos at gmail.com> wrote:
> Hi Gordan,
> 
> I´m talking about the floating IP. (I called it service IP, is wrog the
> name?)
> 
> The real ip of the two nodes is diferent and share the floating IP but in
> that scenario when one service fails (no the whole node) I get one
service
> in one node and one service on the other node but I get the error I
posted.
> 
> for example
> floating IP + BBDD is runing on node1
> floating IP + HTTPD is running on node2
> 
> is this possible?
> 
> thanks
> 
> ESG
> 
> 
> 
> 2009/4/17 Gordan Bobic <gordan at bobich.net>
> 
>> You can't have the same IP on multiple machines at the same time. That
>> much should be obvious before even thinking about clustering.
>>
>> You can, however configure floating IPs as resources that RHCS will
>> fail over between cluster nodes. Only one node will have a particular
>> IP address at any one time, but if that node fails, the floating IP
>> will get migrated to one of the surviving nodes.
>>
>> Any number of services can run on a floating IP. There is no need
>> to have one floating IP per service.
>>
>> Gordan
>>
>> On Fri, 17 Apr 2009 13:23:30 +0200, ESGLinux <esggrupos at gmail.com>
wrote:
>> > Hi,
>> >
>> > thanks for your answer
>> >
>> > I suspected  so,
>> >
>> > can I say as an axiom: One service needs One IP? ( One man, One vote
>> > ;-)
>> )
>> >
>> > and if is this true, has it sense to configure ip resources as shared?
>> > it
>> > must be better to configure as a private resource, isnt it?
>> >
>> > Greetings,
>> >
>> > ESG
>> >
>> > 2009/4/17 Juan Ramon Martin Blanco <robejrm at gmail.com>
>> >
>> >>
>> >>
>> >> On Fri, Apr 17, 2009 at 12:57 PM, ESGLinux <esggrupos at gmail.com>
>> >> wrote:
>> >>
>> >>> Hello all,
>> >>>
>> >>> I have a doubt about using the same service ip with two diferent
>> >>> services
>> >>> in two diferent nodes of my two-nodes-cluster.
>> >>
>> >>
>> >>>
>> >>> I´ll explain it a litle:
>> >>>
>> >>> I have two services: BBDD and HTTPD
>> >>>
>> >>> I have configured a shared IP: 192.168.1.100
>> >>>
>> >> Hi,
>> >> You _must_ use a different  IP, cannot have the same IP on different
>> >> machines.
>> >>
>> >> Greetings,
>> >> Juanra
>> >>
>> >>>
>> >>> two nodes: node1 and node2.
>> >>>
>> >>> When I run the two services on node1 all runs ok. If I try to
>> >>> relocate
>> >>> one
>> >>> service, with
>> >>>
>> >>> clusvcadm -r BBDD -m node2
>> >>>
>> >>> it fails with the error:
>> >>>  in.rdiscd[4805]: setsockopt (IP_ADD_MEMBERSHIP): Address already in
>> use
>> >>>  in.rdiscd[4805]: Failed joining addresses
>> >>>
>> >>> I suposse that is because one services is on node1 with the ip and
>> >>> the
>> >>> other trys to run in node2 with the same ip.
>> >>>
>> >>> So my question is if it is possible to run the services this way or
I
>> >>> need
>> >>> an ip per service?
>> >>> (I have tested that with 2 diferent ips I can run BBDD on node1 an
>> HTTPD
>> >>> on node2)
>> >>>
>> >>> Thanks in advance
>> >>>
>> >>> ESG
>> >>>
>> >>>
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>> >>>
>> >>
>> >>
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