I'd like to tell you about my felicity with localapps. Last spring when I finally got LTSP running and throughout the spring firefox did most of what I asked it to do... except it couldn't do flash video and even java applets like the ones at this famous site <http://phet.colorado.edu/simulations/>were very pokey. But that was pretty much OK. But, what brought my curriculum to it's knees was not being able to run CmapTools, a java based application. The server would bog down with just 1 or at max 2 computers running CmapTools.
The development of localapps has saved the day for my class/curriculum. Firefox and CmapTools work quite well as localapps using PIII and PIV computers with no more than 512 MB RAM. I can't say enough good stuff about what they let me do. Localapps IS the reason I upgraded to Jaunty. I'll too help you make the move to Jaunty--I can't say number of hours on a thing like this (alas, one never knows), but it is worth it if you need cpu hogs as tools for your students. If I can help let me know as well! Good Luck David On Mon, Nov 16, 2009 at 2:10 PM, Scott Balneaves <[email protected]>wrote: > On Mon, Nov 16, 2009 at 11:08:37AM -0800, john wrote: > > Hi Asmo, > > > > On Mon, Nov 16, 2009 at 10:36 AM, <[email protected]> wrote: > > > > > Do you know what they are doing/what kind of web pages they are surfing > - > > > flash, java, lots of pictures, some kind of embedded movies or embedded > > > audio players, lots of popup windows and so on - FF has n+1 plugins - > bad, > > > bad dog. But maybe FF is not so bad, but bad design for web pages can > do > > > that. > > > > They are probably surfing all of the above, since that is the nature > > of the web these days. I think If > > LTSP is going to be viable > > Right, because we're only celebrating our 10th anniversary. It's not like > we're viable or anything :) > > > it has to be able to work at least as well > > as other computers that kids use > > e.g. 4 year old stand alone workstations, 2Ghz, running WinXP with 512 > > mb ram. > > Well, it certainly does. I run about 40 people off one server. Trick is, > I > don't load flash. Now, I'm at a business, and can control this. Flash is > a > "poorly" behaved application: it essentially assumes you're one person > running > on 1 machine. So if you have 30 kids trying to watch flash movies, yeah, > you > either need a machine with 30x the power of your 2 ghz machine, or you need > to > spread the load around. > > Which is why we developed localapps. Offload the firefox on the thin > client. > > > If LTSP/Ubuntu can't manage that the students and teachers > > don't tend > > to be sympathetic. We are using google apps a lot these days, and it > > would be a bad thing for the future of LTSP at our district if we > > figured out that LTSP wasn't up to Web 2.0 or what have you. > > LTSP is NOT a panacea. A thin client will never, EVER be 100% of the > experience of a full workstation. We've done lots of things to make LTSP > as > "like" a full workstation as we can, with things like Localapps, that > allows > you to offload some of the work on the thin client itself. There's also > Stephane's ltsp-cluster work which can also address this problem. > > However, the reality is, if you've got 30 kids each consuming 2ghz of > processing power playing with flash stuff, then you're either going to need > the > equivalent of a 60ghz processor, or enough processors (say, 5 3ghz intel > quadcores) to come up to the same processing power. > > Or, help out projects like Gnash which do the same thing for MUCH less cpu. > By > way of a "single case" instance, here's a line out of top, with me viewing > a > youtube video using the adobe flash player: > > 2049 sbalneav 20 0 495m 120m 35m S 38 6.0 4:09.80 firefox > > The "38" column's important. That's 38% cpu usage. This is on a dual-core > 3.0ghz workstation with 2 gigs of ram. A not inconsiderable box. 38%, > over a > 1/3 busy. So, if I hosted 2 other terminals, and THEY were watching > youtube, > I'd be at 100% util. > > Now, Here's me watching the same video, using Totem as my movie viewer: > > 4208 sbalneav 20 0 201m 43m 20m S 6 2.2 0:02.41 totem > > 6 percent. So, if I had 15 other terminals hanging off my box, watching > youtube videos, I'd be at 100% > > 3. Versus 16. > > The problem here isn't LTSP. LTSP can't "manufacture" cpu cycles out of > thin > air. If a badly behaved application uses up all your cpu cycles, there's > nothing LTSP can do about that: it's just a way of running remote X. > > > Thanks, I am defiantly looking around for Firefox optimization tricks, > > although this link is about memory issues and my problem seems to be > > CPU usage on the server. Running top on the thin clients shows me that > > I have ram to spare. > > Then LocalApps may be your answer. > > > As I said, my question is partly a philiopical rumination e.g I am > > really wondering why Linux/LTSP can be brought to it's knees by a > > single user running a web-browser. > > Because LTSP hasn't been brought to it's knees. The SERVER has been > brought to > it's knees by flash. > > It's just that, WITHOUT ltsp, you never SEE the box being brought to it's > knees > because, well, while you're watching the video, you're not doing anything > else. > > Scott > > -- > Scott L. Balneaves | The closest you will ever come in this life to an > Systems Department | orderly universe is a good library. > Legal Aid Manitoba | -- Ashleigh Brilliant > > -- > edubuntu-users mailing list > [email protected] > Modify settings or unsubscribe at: > https://lists.ubuntu.com/mailman/listinfo/edubuntu-users >
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