[Opensim-dev] Hey all, Grid Comms, border crossings, Request for comments, red regions and toler

[Stefan Andersson]

*general enthusiasm regarding implementing more and stable protocol*
/Stefan



> Date: Fri, 18 Jan 2008 18:26:14 -0500> From: teravus at gmail.com> To: opensim-dev at lists.berlios.de> Subject: [Opensim-dev] Hey all, Grid Comms, border crossings, Request for comments, red regions and tolerance to network failure.> > Hi everyone> > People are practically begging for more reliable grid comms. So,> naturally, I want to give it to them. I really want to do it with> the least amount of work/turnaround time as possible. We've all got> only so much time to work on something.> > So, at least with border crossings, I've observed a few phenomena> > 1. Fly off into infinity> 2. Get put arbitrarily in a spot in the region you were previously in> and get stuck there> > Item one is almost exclusively from child agent disconnects (where a> region that you're a child agent in says, 'close was called' but you> didn't actually want it to). Eventually the region will turn red on> your minimap.> > Item number two seems to be corruption of some kind. It could be a> race condition or lack of synchronization with the client.> > Fact: When a region disconnects on your minimap in llsimulators, the> region will appear again.> > If you watch the console you'll see that the region that you're a root> agent in sends the 'disable simulator' message and then the 'enable> simulator' message.> > This implies that when you get disconnected as a child agent from the> region you're a child in, 'that region' mentions the fact that 'it> lost you' to the region you're a root agent in. Then the region> you're a root agent in sends the 'disable simulator message' and then> sends the 'enable simulator' message to reconnect you to that region.> > Fact: When a region goes red on your minimap with opensim, the region> will never be available again until you relog and when you try to> cross the border, you will fly off into infinity. Even if the region> hasn't turned red *yet*, you will still fly off into infinity.> > So, MW suggested I post a request for comments on this topic since it> has some potential to affect everyone.> > Here's what I propose> > When sending a child agent notification, the current region is also> included so that, when a child agent disconnects, the region can tell> the neighbor that the child is a root agent in to re-inform the agent> of the neighbor.> > Add a routine that the clientview.close method calls in the scene> which checks for a child agent and sends a 'I lost em' message to the> region the agent came from. From there the simulator with the root> agent in it can make the choice to send the child the reconnect> messages or not.> > This will ensure that a child agent connection is established.> > Ensuring that a child agent connection is established will make border> crossings more successful and less of Item one from above will occur.> > I'm not looking to re-do the protocol entirely. I want to make it> more tolerant to the inevitable network failure. I'm not looking to> change much.> > I also don't really want to change any of the existing protocol stuff.> We need a child agent data update anyway.. and it's half> implemented already in the OSG1 code(for a month now).> > The child agent data update contains things like.. child throttles..> so the neighbor sims don't flood the avatar, where the avatar is in> world and what their draw distance is so that we can enable sending> prim to agents in other regions.> > I'm not looking to make OSG2 here. I'm looking to make OSG1 work better.> > With that.. comments anyone?> _______________________________________________> Opensim-dev mailing list> Opensim-dev at lists.berlios.de> https://lists.berlios.de/mailman/listinfo/opensim-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://opensimulator.org/pipermail/opensim-dev/attachments/20080124/4b0496a9/attachment-0001.html>