[Spread-users] New to spread and got some problems

[Jeremy James]

Tobias Stocker wrote:
> I configured two hosts with spread 3.17.4 on Debian Lenny and
> configured a Spread segment with my two servers x.y.z.10 and
> x.y.z.20. I can start spread, connect with the spuser command to the
> local and the remote daemon, so this works fine for me, at least so
> far.

What does your spread.conf look like? (specifically the relevant
'Spread_Segment' section)

> I connect on both machines to the local daemon with spuser and join
> the group test. I expected to see the joins and sent messages on both
> hosts, but instead the messages are only delivered localy. Shouldn't
> the daemon on host A forward the messages to host B if the clients
> are in the same group? Multicasting works, there is no firewall or
> router, so I was just wondering if I understand the way how spread
> works right. In the manuals and docs I can't find anything thereto,
> so I suggest this should work "out of the box".

Multicast will only be used if explicitly specified, eg.

Spread_Segment 255.0.0.1:4803 {
  host1  192.168.1.1
  host2  192.168.1.2
}

And you need to ensure your machine is set up to use multicast. Probably
something like 'route add -net 224.0.0.0 netmask 240.0.0.0 dev eth0'.

Otherwise, using the broadcast address will look something like:

Spread_Segment 192.168.1.255:4803 {
  host1  192.168.1.1
  host2  192.168.1.2
}

Hosts should be able to communicate with both TCP and UDP on the port
given, and UDP on the port above (4804 in this case), on both their
local IP and the given broadcast/multicast IP, just in case some local
firewall rules are still about.

There is also a mode where hosts will communicate directly through
unicast - most likely where the Segment address is not a broadcast or
multicast address for the given hosts, but I haven't had a need to use
that yet.

spuser should indeed be able to see joins, and messages on both machines
to that group.

-jeremy