Mailing List Archive

Hello all,
I need some help setting up mod_backhand. The install instructions are
confusing if you don't know what you are doing and haven't played with
this technology before.


I have mod_backhand running on system B. It is load balaning with
itself just fine.

When I go to set up system C, do I set it up exactly the same?
and what IP do I choose for MulticastStats?

and lastly, I need to set up system A which is going to receive all the
http requests. Do I set it up the same way as B and C since it will not
be serving up any web pages?

I have about 20 virtual sites that I want to start load balancing.
Ideally, request come in to machine A, then are sent to B or C by
mod_backhand.




- daniel.

They should all be configured identically. It is a peer-to-peer model.
If you choose to send requests to only A and set up the rules on A to
exclude itself as a candidate, then you have the set up you want.

Either use a _valid_ multicast address or use your IP broadcast address.

On Friday, November 9, 2001, at 05:38 PM, Daniel Bondurant wrote:
> I need some help setting up mod_backhand. The install instructions are
> confusing if you don't know what you are doing and haven't played with
> this technology before.

Just as a note, the course notes for ApacheCon 2001 are pretty good at
explaining how things work.

http://www.backhand.org/ApacheCon2001/US/backhand_presentation.pdf
http://www.backhand.org/ApacheCon2001/US/backhand_course_notes.pdf

> I have mod_backhand running on system B. It is load balaning with
> itself just fine.
>
> When I go to set up system C, do I set it up exactly the same?

yup.

> and what IP do I choose for MulticastStats?

same.

> and lastly, I need to set up system A which is going to receive all the
> http requests. Do I set it up the same way as B and C since it will not
> be serving up any web pages?

yup. I would set it up identical at first. Then, when you have a
better feel for what's going on, you can augment the configuration on
the different machines.

> I have about 20 virtual sites that I want to start load balancing.
> Ideally, request come in to machine A, then are sent to B or C by
> mod_backhand.

I do the same thing. works well.

--
Theo Schlossnagle
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

Can you send me your conf's so I can poach from them? Would be very helpfull to see an example that is very close to what I want.

What is a vaild multicast address?
is there a range of them? Is somewhere I can read up on it?


>
> > I have about 20 virtual sites that I want to start load balancing.
> > Ideally, request come in to machine A, then are sent to B or C by
> > mod_backhand.
>
> I do the same thing. works well.
>
> --
> Theo Schlossnagle
> 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

On Friday, November 9, 2001, at 06:08 PM, Daniel Bondurant wrote:

> Can you send me your conf's so I can poach from them? Would be very
> helpfull to see an example that is very close to what I want.

They are the default installed mod_backhand configuration directive. (if
you ran ./precompile to patch your apache tree). Otherwise, they are at
the bottom of this email. You will still need to add "Backhand"
directives where you want to do load balancing. Read the course notes
for that.

> What is a vaild multicast address?

225.220.221.20 is a valid IP multicast address.

> is there a range of them? Is somewhere I can read up on it?

Yes there is a range described in RFC 1112. I am sure it has been
updated, but this is still valid (even if not complete). If someone has
more time than I do, they are welcome to track down the most recent IP
Multicast RFC.

http://mirrors.omniti.com/rfcs/1001-1500/rfc1112.txt

--
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


-- directtly from ./precompile (replace @@ServerRoot@@ with your server
root) --

<IfModule mod_backhand.c>
# UnixSocketDir is were the mod_backhand-Arriba file is stored
# (how fast your machine is) This directory must be readable and
writable
# by euid of apache (nobody) Becuase the children have dropped
privledges
# before they connect to UNIX domain socket in this directory.
# This directive is singular.
#
# MulticastStats of the form [<IP ADDR>] <BROADCAST ADDR>:<PORT> will set
# mod_backhand to broadcast server statistics on that address
advertising
# for a server on <IP ADDR> or gethostbyname(gethostname())
# MulticastStats of the form [<IP ADDR>] <MULTICAST ADDR>:<PORT>,<ttl>
will
# set mod_backhand to multicast server statistics on that address
# advertising for a server on <IP ADDR> or gethostbyname(gethostname())
# This directive is singular.
#
# AcceptStats <a.b.c.d>[/<mask>] (like 10.0.0.4 or 10.0.0.0/24) will
accept
# statistics originating from that IP or IP network.
# This option can be cascaded.

UnixSocketDir @@ServerRoot@@/backhand
# MulticastStats 128.220.221.255:4445
MulticastStats 225.220.221.20:4445,1
AcceptStats 128.220.221.0/24

# This is a status of sorts. Visit it and see how valuable it is to you.
<Location "/backhand/">
SetHandler backhand-handler
</Location>
</IfModule>