Mailing List Archive: [mod_backhand-users] backhand startup problem

[mod_backhand-users] backhand startup problem

Aug 21, 2001, 4:19 PM

Post #1 of 7 (1163 views)

Hi,

I have a perplexing problem with mod_backhand. I'm trying to get it to
work on one server before I move onto others. When I start it, I get a
seemingly scrambled IP address on the /backhand/ web interface. Here is
the httpd.conf relevant parts:

<IfModule mod_backhand.c>
<Location "/backhand/">
Backhand off
SetHandler backhand-handler
</Location>
<Location />
Backhand byAge
Backhand byRandom
Backhand byLogWindow
Backhand byLoad
</Location>

UnixSocketDir /export/apache/backhand
MulticastStats cluster-ring-prv 10.131.255.255:4445
AcceptStats 10.131.0.0/16
</IfModule>

when I start apache, /backhand/ shows an IP of 35.128.24.255:80, which
isn't even an IP in our network. Any idea what would cause this? I've
checked the netmasks (class B private), host configurations, etc. If I
start up another server with the same config, it too has a scrambled
looking IP address. cluster-ring-prv is set in the /etc/hosts file for
each host in the cluster as the local interface IP on the 10.* network.

update: as I type here, we tried compiling with gcc instead of cc. Now
we get a scrambled IP upon the first start of apache, but after a
graceful restart, all looks well. ???

TIA
Monte

[mod_backhand-users] backhand startup problem [ In reply to ]

jesus at omniti

Aug 21, 2001, 7:51 PM

Post #2 of 7 (1147 views)

On Tuesday, August 21, 2001, at 07:19 PM, Monte Ohrt wrote:
> I have a perplexing problem with mod_backhand. I'm trying to get it to
> work on one server before I move onto others. When I start it, I get a
> seemingly scrambled IP address on the /backhand/ web interface. Here is
> the httpd.conf relevant parts:
>
> MulticastStats cluster-ring-prv 10.131.255.255:4445
>
> when I start apache, /backhand/ shows an IP of 35.128.24.255:80, which

MulticastStats takes one or two paramaters both of which must by ip
addresses. You are providing a name and the interpretation of the name
as an IP address is causing the problem.

I will add automatic hostname resolution (when I have time) in a future
release. I will of course immediately integrate a patch into CVS is one
mysteriously arrive in my mailbox ;-)

For now, use an IP.

--
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

[mod_backhand-users] backhand startup problem [ In reply to ]

Aug 21, 2001, 10:08 PM

Post #3 of 7 (1160 views)

We have all the web servers in the cluster sharing the same httpd.conf file,
that is why we use a hostname and put the host <-> IP mapping in the
/etc/hosts file. So each web server must use its own httpd.conf file then?

TIA
Monte

Theo Schlossnagle wrote:

> On Tuesday, August 21, 2001, at 07:19 PM, Monte Ohrt wrote:
> > I have a perplexing problem with mod_backhand. I'm trying to get it to
> > work on one server before I move onto others. When I start it, I get a
> > seemingly scrambled IP address on the /backhand/ web interface. Here is
> > the httpd.conf relevant parts:
> >
> > MulticastStats cluster-ring-prv 10.131.255.255:4445
> >
> > when I start apache, /backhand/ shows an IP of 35.128.24.255:80, which
>
> MulticastStats takes one or two paramaters both of which must by ip
> addresses. You are providing a name and the interpretation of the name
> as an IP address is causing the problem.
>
> I will add automatic hostname resolution (when I have time) in a future
> release. I will of course immediately integrate a patch into CVS is one
> mysteriously arrive in my mailbox ;-)
>
> For now, use an IP.
>
> --
> 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

[mod_backhand-users] backhand startup problem [ In reply to ]

jesus at omniti

Aug 21, 2001, 10:30 PM

Post #4 of 7 (1145 views)

On Wednesday, August 22, 2001, at 01:08 AM, Monte Ohrt wrote:
> We have all the web servers in the cluster sharing the same httpd.conf
> file,
> that is why we use a hostname and put the host <-> IP mapping in the
> /etc/hosts file. So each web server must use its own httpd.conf file
> then?

MulticastStats will accept just one argument as well. Try neglecting to
specify the "my ip address is" field. This works almost everywhere.
The two parameter version of MulticastStats is only intended to be used
when mod_backhand guesses the local IP of the web server wrong.

--
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

[mod_backhand-users] backhand startup problem [ In reply to ]

Aug 22, 2001, 6:48 AM

Post #5 of 7 (1140 views)

Nope, it picks the primary (public) interface by default. I have to
specify the private network interface to bind to, it doesn't figure that
out by the netmask.

Theo Schlossnagle wrote:
>
> On Wednesday, August 22, 2001, at 01:08 AM, Monte Ohrt wrote:
> > We have all the web servers in the cluster sharing the same httpd.conf
> > file,
> > that is why we use a hostname and put the host <-> IP mapping in the
> > /etc/hosts file. So each web server must use its own httpd.conf file
> > then?
>
> MulticastStats will accept just one argument as well. Try neglecting to
> specify the "my ip address is" field. This works almost everywhere.
> The two parameter version of MulticastStats is only intended to be used
> when mod_backhand guesses the local IP of the web server wrong.
>
> --
> 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

--
Monte Ohrt <monte@ispi.net>
http://www.ispi.net/

[mod_backhand-users] backhand startup problem [ In reply to ]

jesus at omniti

Aug 22, 2001, 8:58 AM

Post #6 of 7 (1151 views)

On Wednesday, August 22, 2001, at 09:48 AM, Monte Ohrt wrote:
> Nope, it picks the primary (public) interface by default. I have to
> specify the private network interface to bind to, it doesn't figure that
> out by the netmask.

I assume you mean broadcast not netmask.

So, what is the problem with having your private IP advertised in
mod_backhand. I assume all your machines can reach each other over the
private network. Your web servers aren't running on the private
address? Why not? (There are some reasons not to, but often it doesn't
hurt)

A quick fix for that is the set the machines hostname to something that
looks up as the private IP address.

I agree that the desired behaviour is to have mod_backhand resolve names
to IPs in the first of two arguments to MulticastStats. It is on the
TODO list.

--
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

[mod_backhand-users] backhand startup problem [ In reply to ]

Aug 22, 2001, 11:13 AM

Post #7 of 7 (1150 views)

Theo Schlossnagle wrote:
>
> On Wednesday, August 22, 2001, at 09:48 AM, Monte Ohrt wrote:
> > Nope, it picks the primary (public) interface by default. I have to
> > specify the private network interface to bind to, it doesn't figure that
> > out by the netmask.
>
> I assume you mean broadcast not netmask.
>
> So, what is the problem with having your private IP advertised in
> mod_backhand. I assume all your machines can reach each other over the
> private network. Your web servers aren't running on the private
> address? Why not? (There are some reasons not to, but often it doesn't
> hurt)

We do not have a hardware load balancer. One of the servers is on the
public network, we use this one for the proxy server. The rest of them
are on the private network only. They all have access to each other on
the private network.

>
> A quick fix for that is the set the machines hostname to something that
> looks up as the private IP address.
>
> I agree that the desired behaviour is to have mod_backhand resolve names
> to IPs in the first of two arguments to MulticastStats. It is on the
> TODO list.
>
> --
> 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

--
Monte Ohrt <monte@ispi.net>
http://www.ispi.net/