Regarding the groups work, I have now implemented an OpenSimulator
experimental option, MessageOnlineUsersOnly in
[Groups] as of git master 1937e5f. When set to true this will only
send group IMs to online users. This does not
require a groups service update. I believe OSGrid is going to test
this more extensively soon though it appears to
work fine on Wright Plaza.
It's temporarily a little spammy on the console right now (what
isn't!) with a debug message that says how many online
users it is sending to and how long a send takes.
Unlike Michelle's solution, this works by querying the Presence
service for online users, though it also caches this
data to avoid hitting the presence service too hard.
Even though I implemented this, I'm not convinced that it's the best
way to go - I think Michelle's approach of
sending login/logoff status directly from simulator to groups
service could still be better. My chief concern with
the groups approach is the potential inconsistency between online
status stored there and in the Presence service.
However, this could be a non-issue. Need to give it more thought.
On 14/10/12 22:53, Akira Sonoda wrote:
IMHO finding out which group members are online and sending group
IM/Notice etc. to them actually should not be done by
the region server from which the group IM/notice etc. is sent.
This is a task which should be done centrally in case of OSgrid in
Dallas TX (
http://wiki.osgrid.org/index.php/Infrastructure ). The region
server should only collect the group IM/notice etc. and
send it to the central group server or in the other way receiving
IM/notice etc. from the central group server and
distribute it to the Agents active on the region(s).
That concentrates all distribution on a central point rather than
spreading it amongst simulators. Then OSGrid has
the problem of scaling this up.
Having said that, there are advantages to funnelling things through
a reliable central point. As to which is better
is a complicated engineering issue - the kind of which there are
many in the MMO/VW space.
But there are even other places which can and should be improved. I
did some tests with some viewers counting the web
requests to the central infrastructure:
Test 1: Teleport from a Plaza to one of my regions located on a
server in Europe and afterwards logging out:
Cool VL Viewer: 912 Requests mostly SynchronousRestForms POST
http://presence.osgrid.org/presence ( i guess to inform
all my 809 friends [mostly only 5% online] I am going offline
because the calls to the presence service were done after
i closed the viewer)
Singularity Veiwer: 921 Requests mostly calls to presence after logoff
Teapot viewer: 910 Requests mostly calls to presence after logoff
Astra Viewer: 917 Requests mostly calls to presence after logoff
Firestorm: 1005 Requests mostly calls to presence after logoff
Imprudence: 918 mostly calls to presence after logoff
So far so good. I have no idea why my 760 offline friends have to
be informed that I went offline ...
(Details can be found here:
https://docs.google.com/open?id=0B301xueh1kxdNG1wLWo2YVVfYjA )
Test 2: Direct Login onto my Region and then Logoff-( with
FetchInventory2 disabled )
Cool VL Viewer: 2232 Requests mostly calls to presence ~800 during
login and ~800 during logout and xinventory
Singularity Viwer: 2340 Requests mostly calls to presence and
xinventory
Teapot Viewer: Produced 500+ Threads in a very short time and then
the OpenSim.exe crashed
Astra Viewer: 2831 Request mostly calls to presence and xinventory
Firestorm Viwer: ACK Timeout for me. OpenSim.exe survived on 500
Threads for 30+ minutes producing 4996 Requests mostly
xinventory
Imprudence: 1745 Requests mostly presence
Again why do all my 809 friends have do be verified with single
requests? Then why this difference in xinventory
Requests? And why are both Teapot and Firestorm producing so many
Threads in such a short time? and bring OpenSim.exe to
crash or closely to crash ...
( Details can be found here:
https://docs.google.com/open?id=0B301xueh1kxdMDJxWm5UR2QtU2c )
The presence information is useful data and it was possible in git
master commit da2b23f to change the Friends module
to fetch all presence data in one call for status notification when
a user goes on/offline, rather than make a
separate call for each friend.
This should be more efficient since only the latency and resources
of one call is required. However, since each
friend still has to be messaged separately to tell them of the
status change I'm not sure how much practical effect
this will have.
Test 3: Direct Login to my Region with FetchInventory2 enabled.
Teapot Viewer: I closed the viwer after 30 minutes. Number of
Threads were still rising up to 260. In the end i counted
30634 xinventory requests... My Inventory has 14190 items !!!
Firestorm Viwer: Quite normal approx 2020 Requests ... quite some
slow FetchInventoryDescendandts2 Caps. with 100 sec
max
Regarding inventory service, unfortunately many viewers appear to
behave very aggressively when fetching inventory
information. For instance, I'm told that if you have certain types
of AO enabled - some viewers will fetch your
entire inventory. The LL infrastructure may be able to cope with
this but the more modest machines running grids can
have trouble, it seems.
I'm not sure what the long term solution is. I suspect it's
possible to greatly increase inventory fetch efficiency,
possibly by some kind of call batching. Or perhaps there's some
viewer-side caching that OpenSimulator isn't working
with properly.
( Details can be found here:
https://docs.google.com/open?id=0B301xueh1kxdNEtEeUVFamU1QUE )
Just my observations this week end.
Akira
2012/10/13 Justin Clark-Casey <[email protected]
<mailto:[email protected]>>
Hi Michelle. I've now had some more time to think about this.
In fact, I established a proposal summary page at
[1] which I'll change as we go along (or please feel free to
change yourself). We do need to fix this problem of
group IM taking massive time with groups that aren't that big.
I do like the approach of caching online status (and login
time) in the groups service.
1. It's reasonably simple.
2. One network call to fetch online group members per IM.
3. May allow messaging across multiple OpenSimulator
installations.
However, this approach does mean
1. Independently updating the groups services on each
login/logout. I'm not saying this is a problem, particularly
if it saves traffic later on.
2. Groups service has to deal with extra information. Again,
this is fairly simple so not necessarily a fatal
issue though it does mean every groups implementations needs to
do this in some manner.
3. Online cache is not reusable by other services in the future.
On a technical note, the XmlRpc groups module does in theory
cache data for 30 seconds by default, so a change in
online status may not be seen for upto 30 seconds. I
personally think that this is a reasonable tradeoff.
Rather, of the above cons, 3 is the one I'm finding most
serious. If other services would also benefit from online
status caching in the future, they would have to implement
their own caches (and be updated from simulators).
I do agree that making a GridUser.LoggedIn() call for every
single group member on every single IM is unworkable.
Even if this is only done once and cached for a certain
period of time it could be a major issue for large groups.
So an alternative approach could be to add a new call to
GridUser service (maybe LoggedIn(List<UUID>) that will only
return GridInfo for those that are logged in. This could then
be cached simulator-side for a certain period of time
(e.g. 30 seconds like the groups information) and used for
group IM.
This has the advantages that
1. Groups and future services don't need to do their own login
caching.
2. Future services can use the same information and code
rather than have to cache login information themselves.
However, it does
1. Require GridUserInfo caching simulator-side, I would judge
this to be a more complex approach.
2. Mean that during the cache period, new online group
messages will not receive messages. (this is going to
happen with GetGroupMembers() caching anyway).
3. Traffic is still generated to the GridUser service at the
end of every simulator-side caching period. This is
probably not a huge burden.
So right now, I'm somewhat more in favour of a GridUserInfo
simulator-side caching approach than caching login
information within the groups service. However, unlike you, I
haven't actually tried to implement this approach so
there may well be issues that I haven't seen.
What do you think, Michelle (or anybody else)?
On 10/10/12 19:47, Michelle Argus wrote:
http://code.google.com/p/__flotsam/
<http://code.google.com/p/flotsam/> is the the current flotsam
version and
points to the github repro which I forked and
then patched.
None of the changes I proposed in my git fork have been
implemented, neither in opensim nor in flotsam.
Consider my proposal as a quick fix for the time beeing
which does not solve all other issues mentioned by
later
mailings.
Am 09.10.2012 10:24, schrieb Ai Austin:
Michelle Argus on Wed Oct 3 18:00:23 CEST 2012:
I have added some changes to the group module of
OpenSim and the flotsam server.
...
The changes can be found in the 2 gits here:
<https://github.com/MAReantals__>https://github.com/MAReantals
NB: Both changes to flotsam and opensim are
backward compatible and do
not require that both parts are updated. If some
simulators are not
updated it can happen that some groupmembers do not
receive
groupmessages as their online status is not updated
correctly. In a grid
like OSgrid my recomendation would thus be to first
update the
simulators and at a later stage flotsam.
Hi Michelle... I am looking at what is needed to update
the Openvue grid which is using the flotsam
XmlRpcGroups
module. the GITHub repository has the changes from a
few days ago... but I wonder if there has been an
update/commit
into the main Opensim Github area already. I cannot
see a related commit looking back over the last week
or so. Is
the core system updated so this module is up to date in
that? I also note that the Opensim.ini.example file
contains
a reference to http://code.google.com/p/__flotsam/
<http://code.google.com/p/flotsam/> for details of how to
install the service.. but that seems to be
pointing at an out of date version?
I think for the flotsam php end it is straightforward
and I obtained the changed groups.sql and
xmlrpc.php files
needed. But note that people are still pointed via the
opensim.ini.example comments at the old version on
http://code.google.com/p/__flotsam/
<http://code.google.com/p/flotsam/> so that either needs updating
to teh
latest version, or the comment in
opensim.ini.exmaple needs to be changed.
To avoid mistakes, I wonder if you can clarify where to
go for the parts needed and at what revision/date of
OpenSim
0.7.5 dev master this was introduced, what to get and
what to change for an existing service in terms of the
data base
tables, OpenSim.exe instance and the web support php
code areas?
Thanks Michelle, Ai
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Justin Clark-Casey (justincc)
OSVW Consulting
http://justincc.org
http://twitter.com/justincc
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