Hi Prakash,
basically what you describe is the expected behaviour. Without the
extra routing information, the multicast packet will be sent through
the "default" gateway interface, which is "eth0" for all three groups.
As a result group 2 and 3 end up disconnected from group 1.
You should use a different extra route though. Do a:
% route add -host 239.2.11.71 dev eth1
That will keep the default routes for group 2 and 3, but all packets
from the gmond multicast group will go through "eth1". This is, btw.,
in the FAQ.
Another solution is to drop multicast and move to unicast
communication. Select one or two of your nodes as gmond receivers and
have the following directives in gmond.conf (you need 3.0.1 for that):
udp_send_channel {
host = "192.168.2.X"
port = "8649"
}
udp_send_channel {
host = "192.168.2.Y"
port = "8649"
}
udp_recv_channel {
port = "8649"
}
The nodes X and Y will then have all information from the other nodes
and can be used as redundant data sources for "gmetad".
Hope this helps
Martin
--- Prakash Velayutham <[EMAIL PROTECTED]> wrote:
> Hi,
>
> Could someone explain how my configuration directives should be with
> the
> following setup?
>
> Total of 18 compute nodes
>
> 5 compute nodes with eth0 connected to a switch. (192.168.2.*
> network)
> 6 compute nodes with eth1 connected to this switch (192.168.2.*
> network)
> and eth0 connected to a different switch (10.1.21.* network)
> 7 compute nodes with eth1 connected to this switch (192.168.2.*
> network)
> and eth0 connected to a different switch (10.1.74.* network)
>
> The routing table on each group of nodes looks like this
>
> Group 1:
> Destination Gateway Genmask Flags Metric Ref
> Use
> Iface
> 192.168.2.0 0.0.0.0 255.255.255.0 U 0 0
> 0
> eth0
> 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0
> 0
> eth0
> 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0
> 0 lo
> 0.0.0.0 192.168.2.254 0.0.0.0 UG 0 0
> 0
> eth0
>
> Group 2:
> Destination Gateway Genmask Flags Metric Ref
> Use
> Iface
> 192.168.2.0 0.0.0.0 255.255.255.0 U 0 0
> 0
> eth1
> 10.1.21.0 0.0.0.0 255.255.255.0 U 0 0
> 0
> eth0
> 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0
> 0
> eth0
> 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0
> 0 lo
> 0.0.0.0 10.1.21.1 0.0.0.0 UG 0 0
> 0
> eth0
>
> Group 3:
> Destination Gateway Genmask Flags Metric Ref
> Use
> Iface
> 10.1.74.0 0.0.0.0 255.255.255.0 U 0 0
> 0
> eth0
> 192.168.2.0 0.0.0.0 255.255.255.0 U 0 0
> 0
> eth1
> 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0
> 0
> eth0
> 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0
> 0 lo
> 0.0.0.0 10.1.74.1 0.0.0.0 UG 0 0
> 0
> eth0
>
> When I set the default configuration for all the nodes (without a
> mcast_if directive), each of these groups of nodes only show up
> within
> their subnet, so the collection agent only sees one group of nodes
> (depending on which node is first in the data_source line for that
> cluster).
>
> Later I set the configuration for the first group as default and
> changed
> the configuration for the rest of the nodes by adding an "mcast_if
> eth1"
> to the "udp_send_channel" and "udp_recv_channel" groups, but still
> the
> result is the same.
>
> I get the desired result of all nodes multicasting to all the other
> nodes only when I add the following route to the tables of the nodes
> in
> group 2 & group 3. Is there a reason why and is there a way around
> it.
> If I do this change to the routing table, I lose the ability to login
>
> directly to a node.
>
> 0.0.0.0 192.168.2.254 0.0.0.0 UG 0
> 0 0 eth1
>
> Hoping to get an answer to this rather intriguing issue.
>
> Thanks,
> Prakash
>
>
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------------------------------------------------------
Martin Knoblauch
email: k n o b i AT knobisoft DOT de
www: http://www.knobisoft.de
