Mailing List Archive

I think understanding why you want to use mod_backhand in this situation
and learning what you think it will get you may be the first step here.

If you are serving static pages and images, there is no need load
balancing. You can tune a commodity machine running Apache to serve at
least 50 Mbs if not 100+ Mbs for this application. Load should be the
least of your concerns... Unless you are serving a tremendous amount of
traffic in which case you will need a global load balancing system and
mod_backhand may or may not be the right answer.

Sounds to me that with two ISPs you are trying to provide some type of
failover/redundancy to the service you provide -- entirely different
from "load balancing".

So, please describe your situation and detail what you are trying to
accomplish.

On Monday, July 8, 2002, at 03:43 AM, Max Bear wrote:
> I am newbie to mod_backhand and I am very interested
> in this module. I have some questions regarding this
> and hope some body can give me a hand. Thanks a lot.
>
> I have 2 servers which is not in the same network.
> Becasue they located in 2 different ISPs. Their
> content are the same and they are just html page and
> image. I would like to know can mod_backhand still
> load balaning between these 2 servers in this
> situation?
>
> If both server have the same doamin name, for example,
> the domain name of Server A is www.host.com and Server
> B is also www.host.com too. If I install mod_backhand
> at Server A, is it mean people will still stay at the
> same domain if they redirect o Server B? Becasue I
> don't want people know they are redirect to another
> domain name.


--
Theo Schlossnagle
Principal Consultant
OmniTI Computer Consulting, Inc. -- http://www.omniti.com/
Phone: +1 301 776 6376 Fax: +1 410 880 4879
1024D/82844984/95FD 30F1 489E 4613 F22E 491A 7E88 364C 8284 4984
2047R/33131B65/71 F7 95 64 49 76 5D BA 3D 90 B9 9F BE 27 24 E7

Thanks Schlossnagle.

Yes, I receive tremendous amount of traffic so I need
to spread the server load and bandwidth between 2
servers.

My ISP cannot put my servers into the same subnet. So
I have 2 servers in 2 different ISPs.

In my situation, is mod_backhand still suitable for my
use?

Thanks.

Max

--- Theo Schlossnagle <jesus@omniti.com> wrote:
> I think understanding why you want to use
> mod_backhand in this situation
> and learning what you think it will get you may be
> the first step here.
>
> If you are serving static pages and images, there is
> no need load
> balancing. You can tune a commodity machine running
> Apache to serve at
> least 50 Mbs if not 100+ Mbs for this application.
> Load should be the
> least of your concerns... Unless you are serving a
> tremendous amount of
> traffic in which case you will need a global load
> balancing system and
> mod_backhand may or may not be the right answer.
>
> Sounds to me that with two ISPs you are trying to
> provide some type of
> failover/redundancy to the service you provide --
> entirely different
> from "load balancing".
>
> So, please describe your situation and detail what
> you are trying to
> accomplish.
>
> On Monday, July 8, 2002, at 03:43 AM, Max Bear
> wrote:
> > I am newbie to mod_backhand and I am very
> interested
> > in this module. I have some questions regarding
> this
> > and hope some body can give me a hand. Thanks a
> lot.
> >
> > I have 2 servers which is not in the same network.
> > Becasue they located in 2 different ISPs. Their
> > content are the same and they are just html page
> and
> > image. I would like to know can mod_backhand still
> > load balaning between these 2 servers in this
> > situation?
> >
> > If both server have the same doamin name, for
> example,
> > the domain name of Server A is www.host.com and
> Server
> > B is also www.host.com too. If I install
> mod_backhand
> > at Server A, is it mean people will still stay at
> the
> > same domain if they redirect o Server B? Becasue I
> > don't want people know they are redirect to
> another
> > domain name.
>
>
> --
> Theo Schlossnagle
> Principal Consultant
> OmniTI Computer Consulting, Inc. --
> http://www.omniti.com/
> Phone: +1 301 776 6376 Fax: +1 410 880 4879
> 1024D/82844984/95FD 30F1 489E 4613 F22E 491A 7E88
> 364C 8284 4984
> 2047R/33131B65/71 F7 95 64 49 76 5D BA 3D 90 B9 9F
> BE 27 24 E7
>
>
> _______________________________________________
> backhand-users mailing list
> backhand-users@lists.backhand.org
>
http://lists.backhand.org/mailman/listinfo/backhand-users


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wouldn't DNS round robbin be best in this case?


On Mon, 2002-07-08 at 16:49, Max Bear wrote:
> Thanks Schlossnagle.
>
> Yes, I receive tremendous amount of traffic so I need
> to spread the server load and bandwidth between 2
> servers.
>
> My ISP cannot put my servers into the same subnet. So
> I have 2 servers in 2 different ISPs.
>
> In my situation, is mod_backhand still suitable for my
> use?
>
> Thanks.
>
> Max
>
> --- Theo Schlossnagle <jesus@omniti.com> wrote:
> > I think understanding why you want to use
> > mod_backhand in this situation
> > and learning what you think it will get you may be
> > the first step here.
> >
> > If you are serving static pages and images, there is
> > no need load
> > balancing. You can tune a commodity machine running
> > Apache to serve at
> > least 50 Mbs if not 100+ Mbs for this application.
> > Load should be the
> > least of your concerns... Unless you are serving a
> > tremendous amount of
> > traffic in which case you will need a global load
> > balancing system and
> > mod_backhand may or may not be the right answer.
> >
> > Sounds to me that with two ISPs you are trying to
> > provide some type of
> > failover/redundancy to the service you provide --
> > entirely different
> > from "load balancing".
> >
> > So, please describe your situation and detail what
> > you are trying to
> > accomplish.
> >
> > On Monday, July 8, 2002, at 03:43 AM, Max Bear
> > wrote:
> > > I am newbie to mod_backhand and I am very
> > interested
> > > in this module. I have some questions regarding
> > this
> > > and hope some body can give me a hand. Thanks a
> > lot.
> > >
> > > I have 2 servers which is not in the same network.
> > > Becasue they located in 2 different ISPs. Their
> > > content are the same and they are just html page
> > and
> > > image. I would like to know can mod_backhand still
> > > load balaning between these 2 servers in this
> > > situation?
> > >
> > > If both server have the same doamin name, for
> > example,
> > > the domain name of Server A is www.host.com and
> > Server
> > > B is also www.host.com too. If I install
> > mod_backhand
> > > at Server A, is it mean people will still stay at
> > the
> > > same domain if they redirect o Server B? Becasue I
> > > don't want people know they are redirect to
> > another
> > > domain name.
> >
> >
> > --
> > Theo Schlossnagle
> > Principal Consultant
> > OmniTI Computer Consulting, Inc. --
> > http://www.omniti.com/
> > Phone: +1 301 776 6376 Fax: +1 410 880 4879
> > 1024D/82844984/95FD 30F1 489E 4613 F22E 491A 7E88
> > 364C 8284 4984
> > 2047R/33131B65/71 F7 95 64 49 76 5D BA 3D 90 B9 9F
> > BE 27 24 E7
> >
> >
> > _______________________________________________
> > backhand-users mailing list
> > backhand-users@lists.backhand.org
> >
> http://lists.backhand.org/mailman/listinfo/backhand-users
>
>
> __________________________________________________
> Do You Yahoo!?
> Sign up for SBC Yahoo! Dial - First Month Free
> http://sbc.yahoo.com
>
> _______________________________________________
> backhand-users mailing list
> backhand-users@lists.backhand.org
> http://lists.backhand.org/mailman/listinfo/backhand-users

On Monday, July 8, 2002, at 07:49 PM, Max Bear wrote:

> Thanks Schlossnagle.
>
> Yes, I receive tremendous amount of traffic so I need
> to spread the server load and bandwidth between 2
> servers.
>
> My ISP cannot put my servers into the same subnet. So
> I have 2 servers in 2 different ISPs.

You are pushing a tremendous amount of traffic and your ISP can't
allocate two servers in the same subnet? That seems a bit incredulous.
How much bandwidth are you pushing?

I would need to understand the nature of the application before
recommending an approach. What are the service uptime and availability
requirements for this service? If they are really business critical
then you should be running an appropriate routing protocol with your two
providers (BGP) so that you can advertise the same IPs over both links.
Just to be clear as to why this is critical, how are you going to
prevent downtime if one of your ISPs drops off the net? You need
routing support to have true dual-homed networks that are
failure-tolerant. Again though, there should be no reason to have these
servers on a different subnet - you should seriously talk to your ISP
about the service level they are providing you.

If your service requirements are a little more relaxed than this, then
you may be able to develop an adhoc request distribution scheme -- maybe
DNS RR with mod_backhand. However, even mild availability requirements
would probably necessitate at the very least two machines on each ISP to
meet failure constraints -- running HA software like wackamole, or
somesort of dedicated hardware HA device.

> In my situation, is mod_backhand still suitable for my
> use?

It could be. There are some examples of doing this in the ApacheCon
London course notes. However, if you are pushing a really large amount
of bandwidth, there will be a lot of money involved with this. Pushing
100Mbs over a server will cost you between $20k and $50k a month from
any reputable provider and that would be only be with a long term
dedicated commitment. If you're pushing that level of bandwidth you
should probably hire someone to review your architecture who has
professional experience doing this sort of thing. (I do this ;-))

Again, the critical metric is not so much the amount of bandwidth you
push, but the uptime requirements for your services. If you have
serious uptime requirements and are operating on a small budget, you
will be much better off using a single service provider and building for
redundancy there.


--
Theo Schlossnagle
Principal Consultant
OmniTI Computer Consulting, Inc. -- http://www.omniti.com/
Phone: +1 301 776 6376 Fax: +1 410 880 4879
1024D/82844984/95FD 30F1 489E 4613 F22E 491A 7E88 364C 8284 4984
2047R/33131B65/71 F7 95 64 49 76 5D BA 3D 90 B9 9F BE 27 24 E7

Hot Diggity-dog, Jethro! (And welcome to the group!)


On Mon, 8 Jul 2002, Max Bear wrote:

> Dear All,
>
> I am newbie to mod_backhand and I am very interested
> in this module. I have some questions regarding this
> and hope some body can give me a hand. Thanks a lot.
>
> I have 2 servers which is not in the same network.
> Becasue they located in 2 different ISPs. Their
> content are the same and they are just html page and
> image. I would like to know can mod_backhand still
> load balaning between these 2 servers in this
> situation?
>
> If both server have the same doamin name, for example,
> the domain name of Server A is www.host.com and Server
> B is also www.host.com too. If I install mod_backhand
> at Server A, is it mean people will still stay at the
> same domain if they redirect o Server B? Becasue I
> don't want people know they are redirect to another
> domain name.
>
> Thanks.
>
> Max
>
> __________________________________________________
> Do You Yahoo!?
> Sign up for SBC Yahoo! Dial - First Month Free
> http://sbc.yahoo.com
>
> _______________________________________________
> backhand-users mailing list
> backhand-users@lists.backhand.org
> http://lists.backhand.org/mailman/listinfo/backhand-users
>

Hi, I'm new with this stuff. I need something that allows me to do
load-balancing, but based in a special criteria. Let's see if I can
explain myself.

I'm currently serving a lot of files (using a CGI), then gathering some
data and pushing it to a database. Now, we need to split the databases
(because of excessive load) but we can't afford to use distributed
databases, nor make big changes to our current setup.

So, we need to split the traffic we got in two sets of servers, and that
servers are going to manage their own connections with the (now smaller)
databases. I was going to use fastforward, but I need to write too much
code to acomplish this (I need to do the balancing using an argument
from the query string...)

The requirements I have are a) I can't change the machine name, so http
redirect is not an option, and b) I need to keep some data unchanged
(remote address, cookies, headers).

My first question is, can mod_backhand do internal redirect without
affect client data? I mean, cookies, headers, _ip_address_?

Thanks in advance, and sorry for my english.

--
Leonardo Herrera
mailto:leus@epublish.cl

Leonardo Herrera wrote:

> Hi, I'm new with this stuff. I need something that allows me to do
> load-balancing, but based in a special criteria. Let's see if I can
> explain myself.
>
> I'm currently serving a lot of files (using a CGI), then gathering
> some data and pushing it to a database. Now, we need to split the
> databases (because of excessive load) but we can't afford to use
> distributed databases, nor make big changes to our current setup.
>
> So, we need to split the traffic we got in two sets of servers, and
> that servers are going to manage their own connections with the (now
> smaller) databases. I was going to use fastforward, but I need to
> write too much code to acomplish this (I need to do the balancing
> using an argument from the query string...)

Very easy with mod_backhand. You can write your own function to make
decisions based on the querystring. You are probably looking at writing
20-30 lines of C to accomplish this.

>
> The requirements I have are a) I can't change the machine name, so
> http redirect is not an option, and b) I need to keep some data
> unchanged (remote address, cookies, headers).
>
> My first question is, can mod_backhand do internal redirect without
> affect client data? I mean, cookies, headers, _ip_address_?

Cookies are unchanges and IP address is unchanges. Headers are very
slightly modified and most likely won't effect you.

> Thanks in advance, and sorry for my english.

Your English is better than that of most American high-school graduates. :-)

--
Theo Schlossnagle
Principal Consultant
OmniTI Computer Consulting, Inc. -- http://www.omniti.com/
Phone: +1 301 776 6376 Fax: +1 410 880 4879
1024D/82844984/95FD 30F1 489E 4613 F22E 491A 7E88 364C 8284 4984
2047R/33131B65/71 F7 95 64 49 76 5D BA 3D 90 B9 9F BE 27 24 E7