CentOS - Jan 2010 - Apache/Cluster issue -- Single public IP address

I want to set up a cluster that is used for web hosting (RHCS cluster).
Recently,
I experimented with a 2 node cluster and was able to run it successfully.
However,
I have started facing some issues with Apache, which I had configured as a
service
using the Cluster configuration tool. To do this Apache needs a floating IP
address.
This address is in addition to the network interface IP address. For example if
my
NIC IP is 192.168.1.1, then I need 192.168.1.2 as a floating IP address, and
this
has to be bound to apache. At least this is what I understood after several
hours
of experimentation. I also figured that if I configured 192.168.1.1 as a cluster
resource and bound it to apache, the cluster manager failed to start apache and
the
NIC was put "off". ( In effect 192.168.1.1 was removed from the NIC ).

However, the Apache service ran fine when bound to the ADDITIONAL IP i.e.
192.168.1.2
( the floating IP ).

The above example was just a lab setup to test the cluster.

My problem is that I only have a single public IP address, to serve my web
server
and my question is this:

Is this the end of the road, for installing apache as a service with ONE public
IP
address??

I am willing to give further info, if required.

Don't bind it to an IP (so listen shows 0.0.0.0) on either node of the
cluster? When the IP address is floated across it will still accept requests
on that then - in additional the the real node IP address.....

Given that you are talking a public IP address however it depends on your
network configuration and ISP setup...

2010/1/8 <avi at myphonebook.co.in>
> I want to set up a cluster that is used for web hosting (RHCS cluster).
> Recently,
> I experimented with a 2 node cluster and was able to run it successfully.
> However,
> I have started facing some issues with Apache, which I had configured as a
> service
> using the Cluster configuration tool. To do this Apache needs a floating IP
> address.
> This address is in addition to the network interface IP address. For
> example if my
> NIC IP is 192.168.1.1, then I need 192.168.1.2 as a floating IP address,
> and this
> has to be bound to apache. At least this is what I understood after several
> hours
> of experimentation. I also figured that if I configured 192.168.1.1 as a
> cluster
> resource and bound it to apache, the cluster manager failed to start apache
> and the
> NIC was put "off". ( In effect 192.168.1.1 was removed from the
NIC ).
>
> However, the Apache service ran fine when bound to the ADDITIONAL IP i.e.
> 192.168.1.2
> ( the floating IP ).
>
> The above example was just a lab setup to test the cluster.
>
> My problem is that I only have a single public IP address, to serve my web
> server
> and my question is this:
>
> Is this the end of the road, for installing apache as a service with ONE
> public IP
> address??
>
> I am willing to give further info, if required.
>
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
>
>
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> Is this the end of the road, for installing apache as a 
> service with ONE public IP
> address??
If I understand clustered services, you have only one
public IP address for the cluster, but that IP address needs
to be a virtual IP which can be point to one or more machines
on private IP adresses.

We have had good success creating HA services using
mysql master-master replication.

	Neil

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From: "avi at myphonebook.co.in" <avi at
myphonebook.co.in>
> I want to set up a cluster that is used for web hosting (RHCS cluster). 
> Recently,
> I experimented with a 2 node cluster and was able to run it successfully. 
> However,
> I have started facing some issues with Apache, which I had configured as a 
> service
> using the Cluster configuration tool. To do this Apache needs a floating IP
> address.
Not sure if I understood correctly but maybe check IPVS...
http://www.linuxvirtualserver.org/software/ipvs.html

JD

avi at myphonebook.co.in wrote:
> Is this the end of the road, for installing apache as a service with ONE
> public IP
> address??
You sure you have the right solution? Using RHCS for web serving
seems really complicated, I would use a load balancer instead. Myself
I have most experience with F5 gear but there is LVS on linux(never
used it). With load balancers you can often offload things like
SSL, compression, etc. It makes life much easier for scaling, since
you can have multiple systems serving content for the same public
IP, and add/remove more at will, really trivial to manage.

Depends on the size of your cluster..

http://www.redhat.com/docs/manuals/csgfs/browse/rh-cs-en/pt-lvs.html

nate

nate <centos at linuxpowered.net> wrote ..
> avi at myphonebook.co.in wrote:
> 
> > Is this the end of the road, for installing apache as a service with
ONE
> > public IP
> > address??
> 
> You sure you have the right solution? Using RHCS for web serving
> seems really complicated, I would use a load balancer instead. Myself
> I have most experience with F5 gear but there is LVS on linux(never
> used it). With load balancers you can often offload things like
> SSL, compression, etc. It makes life much easier for scaling, since
> you can have multiple systems serving content for the same public
> IP, and add/remove more at will, really trivial to manage.
> 
> Depends on the size of your cluster..
> 
> http://www.redhat.com/docs/manuals/csgfs/browse/rh-cs-en/pt-lvs.html
> 
> nate
 I have used LVS before. I wanted to use RHCS for an ISCSI-SAN setup, with GFS.

 LVS can work with RHCS. Cannot afford F5's. Am in the process of trying out

 RHCS with LVS. Otherwise I will fall back on LVS with Mysql replication across
nodes.

You can try heartbeart...

:)

DS

------Original Message------
From: avi at myphonebook.co.in
Sender: centos-bounces at centos.org
To: centos at centos.org
ReplyTo: CentOS mailing list
Subject: [CentOS] Apache/Cluster issue -- Single public IP address
Sent: Jan 8, 2010 11:28 PM

I want to set up a cluster that is used for web hosting (RHCS cluster).
Recently,
I experimented with a 2 node cluster and was able to run it successfully.
However,
I have started facing some issues with Apache, which I had configured as a
service
using the Cluster configuration tool. To do this Apache needs a floating IP
address.
This address is in addition to the network interface IP address. For example if
my
NIC IP is 192.168.1.1, then I need 192.168.1.2 as a floating IP address, and
this
has to be bound to apache. At least this is what I understood after several
hours
of experimentation. I also figured that if I configured 192.168.1.1 as a cluster
resource and bound it to apache, the cluster manager failed to start apache and
the
NIC was put "off". ( In effect 192.168.1.1 was removed from the NIC ).

However, the Apache service ran fine when bound to the ADDITIONAL IP i.e.
192.168.1.2
( the floating IP ).

The above example was just a lab setup to test the cluster.

My problem is that I only have a single public IP address, to serve my web
server
and my question is this:

Is this the end of the road, for installing apache as a service with ONE public
IP
address??

I am willing to give further info, if required.

> My problem is that I only have a single public IP address, to serve my web
server
> and my question is this:
>
> Is this the end of the road, for installing apache as a service with ONE
public IP
> address??
>   
a cluster like that typically needs THREE IP addresses.  one for cluster 
node 1, one for cluster node 2 and one for the shared service, this last 
IP will be assigned to the currently active host and will be the one 
clients use to connect.   the other two addresses are used for 
administration and management.

in addtion, a robust cluster has one or more dedicated networks (these 
can be crossover cables, and can/should use private addressing) for 
redundant heartbeats