There is a ton of interesting engineering challenges on the server side
of these systems. We haven't even begun to scratch the surface. As such,
it's completely unrealistic to expect things like what you describe to
happen any time soon -- at least for interactive, shared, immersive
spaces; non-interactive, non-shared, non-immersive (like Google Earth)
it's another matter. It's also fairly unrealistic to expect those kinds
of optimizations to happen spontaneously and for free. There needs to be
a lot of money thrown in for those things to be prototyped and
experimented with -- research money, for starters; that's the kind of
thing that will keep a lot of graduate students busy for the next few years.
On 7/6/2010 6:54 PM, Mark Malewski wrote:
OpenSim/RealXtend,
Another thought is the issue of "scalability" with the current OpenSim
and/or realXtend Architecture.
Running hundreds (or thousands) of IDLE regions require too many
system resources (RAM, CPU cycles, etc.)
I believe that the basic server core (OpenSim) should eventually be
modified so that ALL regions should have a configurable "timeout"
option field (in the regions.ini file).
http://opensimulator.org/wiki/Configuring_Regions
That way an idle "region timeout" can be set (on a region per region
basis), and this would allow the OpenSim server to shut down idle
regions (based on the "idle timeout" configured in the regions.ini file).
So if a region were completely empty for a particular number of
minutes (let's say a region were empty and idle for 5 minutes, then
the idle region could be shut down automatically after the set "idle
timeout" period for that particular region).
This way idle (and empty) regions are not consuming valuable system
resources.
Then as a user attempts to "teleport" to an idle (empty) region, the
server would simply start that idle region (on-the-fly) so that the
user could teleport into the idle region.
It may create a little bit of a slight "pause" (as an idle region is
started) while teleporting, but you normally experience a pause
anyways while teleporting, so a few additional two or three seconds
shouldn't make that much of a difference when teleporting to an empty
or idle region.
A second improvement upon this, would be a "smart idle regions" grid
option (configurable at the grid and/or region level). The "smart
idle regions" grid option would take things one step further, and
would automatically allow the configuration option to bring nearby
idle regions out of "sleep" mode, and start them automatically (if an
avatar is within a certain number of meters from a nearby neighboring
region).
For example this number could be configurable at the Grid and/or
region level to be anything from 1 meter, to 100 meters, or even 256
meters (thus automatically loading the idle region to the North, the
idle region to the South, the idle region to the East and the idle
region to the West). So that nearby regions could be loaded (as an
avatar gets close to the border of another nearby region).
This way if avatars are using high speed vehicles (aircraft, boats,
trains, etc.) and they are getting close to a region crossing (to
another region that may be idle) that region could automatically be
started (if "smart regions" was enabled), thus making the region
crossing seamless (and in real-time). So that flight simulators and
ship simulators could be developed (with large global high resolution
land region maps of the whole world) that could easily be stored on
any single server. (The idle regions would simply load "on-demand" as
needed).
This way OpenSim core could be used for Science, Educational,
Flight/Train/Ship simulation or even gaming purposes.
So that way an OpenSim/realXtend server could technically store
thousands of regions all on a single server instance (possibly even
50-60GB's of high resolution GIS/terrain/region maps of the whole world).
So that things like high resolution "Global Scenery" could be created
(and downloaded) under a "Creative Commons" license for high
resolution scenery (stored in Mega regions) for OpenSim.
http://www.global-scenery.org/
I do have a military GIS (Imagery Analysis/Intelligence) background,
and don't mind working on things like basic high resolution
OpenSim/realXtend region content creation (empty regions based on high
resolution GIS/DTED data). DTED data could be used to create
elevation maps, and high resolution imagery could be used for terrain
textures.
I believe an OpenSim GIS project would be a very good "basis" for
other projects (educational, gaming, city planning, development,
architectural development and multi-person Flight/Train/Ship
simulation & training development) since terrain/region modules would
be available free for download.
The reason "Smart Regions" (idle region timeouts) would be necessary,
is so things like modeling rural areas like "Yellowstone" National
Park could easily be possible on a small single server (or even a
small single workstation running a single OpenSim/osgrid/realXtend
server instance), since the majority of those regions would usually
remain idle/empty (and with the idle regions shutting down they would
consume NO CPU clock cycles or RAM, thus making "idle" regions
identical to idle web pages that take up nothing more than hard drive
space).
Certain regions (like a lobby, main Plaza, or high-traffic regions)
would need to remain active (no idle timeout) and would simply have a
idle timeout value of "9999". (Which would equate to requiring the
region to be completely idle and empty for a minimum of 9999 minutes,
or about 7 days) before going into a "sleep" or idle "shutdown" mode.
I supposed a timeout value of "0000" could also be used for an
"infinite" time (no idle timeout or idle shut down) so that regions
that want to remain up (forever) with no idle timeout period or idle
shutdown could thus stay running all the time (consuming valuable RAM,
CPU and system resources).
But as we begin to look at global region mapping and developing large
regions (especially from a GIS perspective) then we need to look at
the "flaws" in the current OpenSim server design architecture, and see
that it would simply not be possible to create something like a
virtual 3D world (on a 1:1 virtual/GIS scale) without having billions
of physical servers (and trillions of dollars for physical hardware,
let alone the costs of electricity and hardware just to even run a
single instance). It seems to be a major flaw in the basic design
architecture to require the "always-on" concept of regions without
having a region "idle-timeout" feature.
Wasting RAM and CPU clock cycles on empty/idle regions (without having
an "idle timeout" option would seem like a huge waste of energy, and
system resources, especially when those valuable system resources
could be better spent on active regions with physical avatars that
require the additional processing power and RAM that could be freed up
by shutting down any idle regions (after a specified "time out" period).
Since the majority of the regions would remain empty and idle on a
server (similar to static web pages that are not being accessed or
viewed on a web server), it seems extremely foolish to waste such
valuable system resources (such as server CPU clock cycles and server
RAM, let alone the energy/power) wasted on idle regions that remain
empty and idle (but must be loaded as "always on").
Having an "on-the-fly" system that will shut down idle regions (based
on their configurable regions.ini "time out" value in the regions.ini
file, and automatically load idle regions "on-the-fly" would be much
closer to the way the current web is designed, so that servers can
hold thousands (possibly even millions) of web pages that consume no
system resources (other than physical hard drive space) unless the web
pages are being viewed.
By allowing regions to startup/shutdown dynamically (with a "region
timeout" feature) thus making servers able to hold infinite amounts of
idle regions/land (only limited by the amount of hard drive/disk
storage space, which could easily be expanded via RAID or SAN devices).
System Administrators could put "heavy load" regions on separate
dedicated servers, while keeping other "idle load" regions all on the
same server (for regions that are generally idle and not visited very
frequently).
As we evolve and slowly get into simulation systems, such as aircraft,
train or ship simulators I can see how having large numbers of "idle"
regions would be a requirement for realistic train/ship/aircraft
simulation and gaming (as well as GIS and global flight) and how it
simply would not even be possible to have millions of regions running
all on a single server (due to the current "architectural" problems
with OpenSim).
It just wouldn't even be possible to even create a simple flight,
train or ship simulator using OpenSim (because OpenSim couldn't even
store the image/region scenery maps).
Yet, a small simple "X-Plane" flight simulator can store high
resolution "global scenery" data for the WHOLE world on just 6 or 7
double layer DVD's (about 60+ GB of terrain data) all on a single
workstation.
http://www.global-scenery.org/
I don't mind starting a Global-Scenery package for OpenSim/realXtend
and I do think it would be extremely nice to offer the community high
resolution realistic regions (free of charge under a "creative
commons" license).
The problem with even starting a large content creation project, is
that the current OpenSim architecture is unable to even use it.
It would be a complete waste of time and effort to have realistic
global high resolution terrain regions available for OpenSim to use
for Flight/Train/Ship (as well as Education & Science) simulation but
the whole idea of a large scale GIS/terrain project for
OpenSim/realXtend seems somewhat pointless since the current
realXtend/OpenSim server architecture is not designed to currently
even use/store thousands (or even millions) of idle regions (and the
current server architecture of keeping ALL idle regions running is
"flawed" by architectural design).
It would seem to make much more sense (from an engineering standpoint)
to have the option to shut any idle regions down, and only leave
active regions running (or at least give users/operators/grid owners
the ability to configure regions & a grid to allow for idle region
timeouts). I believe this "region idle time out" time should be
configured in the regions.ini configuration file. With an option of
"9999" for a 7 day idle timeout and a "0000" option to disable the
idle timeout for a particular region (for regions that don't ever want
to shut down due to an idle timeout).
It would make sense to see OpenSim/realXtend support a "smart region"
type of system which servers would/could be configured to shut idle
regions down by default (configurable in the regions.ini file for each
region) and the server could load idle regions "On-The-Fly" freeing up
valuable system resources on a physical server.
By implementing "smart regions" into the OpenSim core, a high
resolution global GIS/terrain project would seem like a viable project
to start (and I wouldn't mind starting such a project) especially for
future science/flight/ship/train simulation. I could probably find
other universities (and sponsors) that would be willing to host mirror
copies of the empty raw .OAR global terrain region files. So that
other developers, educators or users could freely download high
resolution realistic region terrains (for educational, gaming or
simulation purposes).
If OpenSim was able to shut down idle regions on the fly, then it
could be used for flight simulation, terrain simulation, or even
realistic game simulation (could have large high resolution realistic
global terrain maps).
I don't mind starting/doing free "creative commons" (attribution by)
based global GIS/terrain content creation work for the
OpenSim/realXtend community, but the current problem that I see is
that the current OpenSim architecture design would NEVER even be able
to support such a feature (since the current server architecture would
require thousands, or millions or possibly even billions of OpenSim
servers just to handle ONE single copy of "the world" terrain in
high-res region data.
Thus making it completely impossible to ever "sail a ship" or "fly an
aircraft" around the world on a standalone OpenSim server.
I believe the basics of good simulation programs starts with high
resolution image maps (and scenery data). A flight simulation program
is fairly useless without realistic global imagery.
Although the basic default high resolution terrain/region data would
probably only consume about 50-60 GB's of storage space (empty terrain
regions stored in "mega region" OAR format), it would still be
impossible to even store or use the terrain region data on a single
OpenSim server (since an OpenSim server would require that all the
regions be running at the same time, with no way to load/unload the
regions (on-the-fly) as they are accessed or needed. We would need to
have an "idle time-out" feature and also a "load-on-demand" feature to
load regions and shut down idle regions based on a region "idle
time-out" system (and to load nearby regions, and load regions that
users attempt to teleport to).
I apologize for sounding repetitive.
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