[Spread-users] Delays in receiving messages

[Kevin Everets]

Hello,

I'm playing with spread here and running into an issue where there are
delays in receiving messages.

The setup is with three machines, all of which are in separate Spread
segments, though currently the first two are in the same network
subnet.  The config looks like:

Spread_Segment 0.0.0.0:5333 {
  host_a 10.1.1.1
}

Spread_Segment 0.0.0.0:5333 {
  host_b 10.1.1.2
}

Spread_Segment 0.0.0.0:5333 {
  host_c 10.1.2.1
}

Then, on host_b, there's an active sender, sending a message every 0.1
seconds containing the current high-res timestamp.  There's also a
receiver running on host_b (same host) receiving the message and
comparing the timestamp.  If the timestamp differs by more than 0.1
seconds, it prints out the message.

What the result seems to be is that every so often there's a delay in
reception where it seems that messages get buffered up to 2 seconds
and then all of those messages are received by the receiver.  Changing
the Hurry_timeout in membership.c seems to indicate that it is hitting
the Hurry_timeout case (changing this to 10 seconds means that
occasionally messages are buffered by up to 10 seconds).

The question is, why is this happening, and how can it be prevented?
A quick fix seems to be to turn down the Hurry_timeout, but ideally
this shouldn't be necessary since it seems the network shouldn't be
hitting this case.  It's fairly busy with 10 messages per second, and
the reading of the Hurry_timeout is that it seems to be meant for a
relatively inactive network.

Thanks in advance for any direction on this,

K.