[Opensim-dev] Does OpenSim need to leave so many packets marked as reliable?

[Melanie]

Hi,

for my experience, ObjectUpdate and LayerData need to be reliable. 
The loss of those packet types causes bomb craters and ghost prims.

I am totally -1 on changing that in trunk without any option to set 
a flag or something to make them reliable.

I actually modify my opensims to never discard those at all. If I 
don't do that, 12000+ prim sims just won't work.

I will write a bit of code to allow that to be set in the packet 
handler in a bit. Then people who want to can use that to experiment.

Melanie


Justin Clark-Casey wrote:
> Hi there,
> 
> A vast number of the packets that we send out from OpenSim (usually >95% according to the statistics printed to the 
> Linden viewer log on shutdown) are marked as reliable.  This requires that the viewer respond with an ack, and it just 
> doesn't appear that this is done very well when a large number of reliables are sent.  A lot of acks never come and we 
> often appear to end up resending thousands (or in the worst case tens of thousands) of packets.
> 
> In a private experiment I've set Header.Reliable = false for the LayerDataPacket and ObjectUpdatePacket (which appear to 
> be the greatest sent by count, and which are currently reliable by default in libOMV).  Naturally, this cuts down the 
> vast number of resends (and possibly some of the packet_out_of_order messages that come out on the console log) without 
> any apparant ill effects.  However, my testing has been pretty limited so I'm minded to wait until Monday before making 
> any trunk changes, since then I can get a better load test with multiple avatars (this doesn't stop anybody else testing 
> of course :-)
> 
> Any opinions on this?  Is there a good reason for these packets to remain reliable (when resends are probably rare 
> anyway)?  libOMV appears to mark every packet as reliable by default...  and then OpenSim removes this from a couple of 
> them but not from others.
>