On my Minecraft multiplayer server, I have a game called Destruction.
In there the goal is to survive several natural disasters coded within the plugin.
I use the plugin FastAsyncWorldedit to process the block management in the different disasters.
Other stuff I made with async tasks if it was possible.
Now my problem is, that even at 2 players playing it, they are lagging through the world.
(The world is a custom built map 150x150 blocks) TPS is nearly constant at 20* ticks and RAM usage is also not overused.
Does someone know why the hell it still lags from the players view?
I think the problem is FastAsyncWorldEdit. I used that plugin for a while because it runs quite a bit faster, but it has one fatal issue: it's indefinably unstable. I know normal WorldEdit is slow and, in some cases, laggy, but it's a lot better that FAWE. Try switching it out.
If that doesn't work, try this: install PlaceHolderAPI, then run the command /papi ecloud download Player to install the extension. Then install some plugin that allows usage of placeholders. I'd recommend MyCommand. Here's a link to a simple command I rigged up. Place it in the folder marked commands in the MyCommand folder. Then have the glitching players do either /ping or /p to see what their current respective pings are. (Either reload the plugin or restart the server to register custom commands.) If they're above 100, it could potentially cause issues.
Related
In my band, all musicians have both hands busy at any time. However, we want to add whole synthesizer chords (1/4 .. whole note length), maybe triggered by a simple foot switch every time (because playing along a sequencer is currently too difficult for us).
Some time ago I wrote a (Windows) console application in C (MinGW) that converted incoming MIDI events to text, piped that text to an external program (AWK script), and re-converted that external program's text output back to MIDI events.
Basically every sort of filtering or event generation was possible; I actually produced chords triggered by simple control messages; I kept note-ONs in memory to be able to -OFF them whenever a new chord was sent, etc. - the actual processing (execution) times were not a problem at all(!)
But I had to understand that not only latency, but also the notoriously unreliable (with respect to "when", "for how long") user application OS multitasking/switching made this concept practically worthless at least for "real-time" use. There were always clearly perceivable delays, of unpredictable duration.
I read about user-mode driver programming and downloaded some resources, but somehow stopped working on that project without a real result.
Apart from that specific project, I even have some experience in writing small "virtual" machines that allow for expressing exactly the variables, conditionals and math, stored as a token tree and processed quite fast. Maybe there is also the option to embed Lua, V8, or anything like that. So calling another (external) program is not necessarily the issue here, since that can be avoided.
The problem that remains is that the processing as a whole is still done by a (user) application. So I figure there is no way around a (user mode) driver, in this scenario.
Alternatively, I was even considering (more "real-time") hardware - a Raspi or the like - but then the MIDI interface may be an additional challenge.
Is there any hardware or software solution (or project) available that may serve as a base for such a _Generic MIDI filter/processor_? Apart from predictable timing behaviour, it is desirable not to need a (C) compilation environment when building filters/rules, since that "creative" step will probably happen in our rehearsal room (laptop available), which is certainly not a "programming lab". Text-based "programs" are fine - for long-term I'll maybe build a GUI for wiring/generating rules anyway.
MIDI is handled pretty well in Windows. I'm not sure the source of the original problems you had. No doubt there is some latency though.
You can handle this in real time with a microcontroller. The good news is that you don't even have to build the hardware. Off-the-shelf controllers are available for this. For example: http://www.midisolutions.com/prodevp.htm
We are running a build of our application using Dojo 1.9 and the build itself is taking an inordinate amount of time to complete. Somewhere along the lines of 10-15 minutes.
Our application is not huge by any means. Maybe 150K LOC. Nothing fancy. Furthermore, when running this build locally using Node, it takes less than a minute.
However, we run the build on a RHEL server with plenty of space and memory, using Rhino. In addition, the tasks are invoked through Ant.
We also use Shrinksafe as the compression mechanism, which could also be the problem. It seems like Shrinksafe is compressing the entire Dojo library (which is enormous) each time the build runs, which seems silly.
Is there anything we can do to speed this up? Or anything we're doing wrong?
Yes, that is inordinate. I have never seen a build take so long, even on an Atom CPU.
In addition to the prior suggestion to use Node.js and not Rhino (by far the biggest killer of build performance), if all of your code has been correctly bundled into layers, you can set optimize to empty string (don’t optimize) and layerOptimize to "closure" (Closure Compiler) in your build profile so only the layers will be run through the optimizer.
Other than that, you should make sure that there isn’t something wrong with the system you are running the build on. (Build files are on NAS with a slow link? Busted CPU fan forcing CPUs to underclock? Ancient CPU with only a single core? Insufficient/bad RAM? Someone else decided to install a TF2 server on it and didn’t tell you?)
I'm new to programming, taking MIT's 6.00. While watching the Dynamic Programming lecture a simple question occurred to me: Is there any kind of built-in feature (for computers in general) to detect repetitive tasks and compensate?
I realize that's quite vague. I was working on my grandfather's computer because he had been complaining that it was slow. Indeed, it would lag for up to 15 seconds at a time, waiting for programs to open, etc. When I upgraded the RAM, the problem was gone. So if the computer was constantly having to write page ins and page outs to disk, why couldn't it have just popped up a little message suggesting a RAM upgrade? That would save quite a bit of time.
Computers are good at performing tasks quickly but slow code can be, well, slow. Can that be automated? Is this even a legitimate question?
In the example you describe the code isn't slow because it's reading/writing to disk. It's slow because it isn't actually doing anything but instead is waiting for the OS to page in and out to disk.
Also, a RAM upgrade isn't always the solution to frequent paging (say buggy program leaking memory or something).
It's not really possible in the general sense for the OS to detect what all the possible issues are and suggest a solution. That is in fact a variation of the Halting Problem.
It's impossible in general for a computer to know whether a slowness was because it's running an operation that fundamentally takes a long time to finish, or whether it's taking more time than it should really be.
Also, even if you've identified that an operation is slow, it's even more difficult to diagnose the precise reason why it is slow. Sometimes it's because you need more RAM, other times because slow network, or slow disk, or slow CPU. This is even more harder if the checker is running inside the same machine that it is running on since it's also experiencing the slowness itself.
However there are several things that can be done under certain limited situations. Many popular OSes (e.g. Windows, Linux, Android) can detect slow response to user input, and will offer to either give more time or force close applications (Android) or draw the not responding window in grayscale (Linux), or in bluish tint (Windows), if the application fails to respond to user input within certain period of time.
I want to read how much data from 3G every app uses. Is this is possible in iOS 5.x ? And in iOS 4.x? My goal is for example:
Maps consumed 3 MB from your data plan
Mail consumed 420 kB from your data plan
etc, etc. Is this possible?
EDIT:
I just found app doing that: Data Man Pro
EDIT 2:
I'm starting a bounty. Extra points goes to the answer that make this clear. I know it is possible (screen from Data Man Pro) and i'm sure the solution is limited. But what is the solution and how to implement this.
These are just hints not a solution. I thought about this many times, but never really started implementing the whole thing.
first of all, you can calculate transferred bytes querying network interfaces, take a look to this SO answer for code and a nice explanation about network interfaces on iOS;
use sysctl or similar system functions to detect which apps are currently running (and for running I mean the process state is set to RUNNING, like the ps or top commands do on OSX. Never tried I just suppose this to be possible on iOS, hoping there are no problems with app running as unprivileged user) so you can deduce which apps are running and save the traffic stats for those apps. Obviously, given the possibility to have applications runnning in background it is hard to determine which app is transferring data.
It also could be possible to retrieve informations about network activity per process/app like nettop does on OSX Lion, unfortunately nettop uses the private framework NetworkStatistics.framework so you can't dig something out it's implementation;
take into account time;
My 2 cents
No, all applications in iOS are sandboxed, meaning you cannot access anything outside of the application. I do not believe this is possible. Neither do I believe data-traffic is saved on this level on the device, hence apple would have implemented it in either the network page or the usage page in Settings.app.
Besides that, not everybody has a "data-plan". E.g. in Sweden its common that data-traffic is free of charge without limit in either size or speed.
Our network team is thinking of setting up a virtual desktop environment (via Windows 2008 virtual host) for each developer.
So we are going to have dumb terminals/laptops and should be using the virtual desktops for all of our work.
Ours is a Microsoft shop and we work with all versions of .net framework. Not having the development environments on the laptops is making the team uncomfortable.
Are there any potential problems with that kind of setup? Is there any reason to be worried about this setup?
Unless there's a very good development-oriented reason for doing this, I'd say don't.
Your developers are going to work best in an environment they want to work in. Unless your developers are the ones suggesting it and pushing for it, you shouldn't be instituting radical changes in their work environments without very good reasons.
I personally am not at all a fan of remote virtualized instances for development work, either. They're often slower, you have to deal with network issues and latency, you often don't have as much control as you would on your own machine. The list goes on and on, and little things add up to create major annoyances.
What happens when the network goes down? Are your dev's just supposed to sit on their hands? Or maybe they could bring cards and play real solitare...
Seriously, though, Unless you have virtual 100% network uptime, and your dev's never work off-site (say, from home) I'm on the "this is a Bad Idea" side.
One option is to get rid of your network team.
Seriously though, I have worked with this same type of setup through VMWare and it wasn't much fun. The only reason why I did it was because my boss thought it might be worth a try. Since I was newly hired, I didn't object. However, after several months of programming this way, I told him that I preferred to have my development studio on my machine and he agreed.
First, the graphical interface isn't really clear with a virtual workstation since it's sending images over the network rather than having your video card's graphical driver render the image. Constant viewing of this gave me a headache.
Secondly, any install of components or tools required the network administrator's help which meant I had to hurry up and wait.
Third, your computer is going to process one application faster than your server is going to process many apps and besides that, it has to send the rendered image over the network. It doesn't sound like it slows you down but it does. Again, hurry up and wait.
Fourth, this may be specific to VMWare but the virtual disk size was fixed to 4GB which to my network guy seemed to think it was enough. This filled up rather quickly. In order for me to expand the drive, I had to wait for the network admin to run partition magic on my drive which screwed it up and I had to have him rebuild my installation.
There are several more reasons but I would strongly encourage you to protest if you can. Your company is probably trying to impliment this because it's a new fad and it can be a way for them to save money. However, your productivity time will be wasted and that needs to be considered as a cost.
Bad Idea. You're taking the most critical tool in your developers' arsenal and making it run much, much, much slower than it needs to, and introducing several critical dependencies along the way.
It's good if you ever have to develop on-site, you can move your dev environment to a laptop and hit the road.
I could see it being required for some highly confidential multiple client work - there is a proof that you didn't leak any test data or debug files from one customer to another.
Down sides:
Few VMs support multiple monitors - without multiple monitors you can't be a productive developer.
Only virtualbox 3 gets close to being able to develop for opengl/activeX on a VM.
In my experience Virtual environments are ideal for test environments (for testing deployments) and not development environments. They are great as a blank slate / clean sheet for testing. I think the risk of alienating your developers is high if you pursue this route. Developers should have all the best tools at their disposal, i.e. high spec laptop / desktop, this keeps morale and productivity high.
Going down this route precludes any home-working which may or may not be an issue. Virtual environments are by their nature slower than dedicated environments, you may also have issues with multiple monitor setups on a VM.
If you go that route, make sure you bench the system aggressively before any serious commitment.
My experience of remote desktops is that it's ok for occasional use, but seldom sufficient for intensive computations and compilation typical of development work, especially at crunch time when everyone needs resources at the same time.
Not sure if that will affect you, but both VMWare and Virtual PC work very slow when viewed via Remote Desktop. For some reason Radmin (http://www.radmin.com/ ) does a much better job.
I regularly work with remote development environments and it is OK (although it takes some time to get used to keep track in which system you're working at the moment ;) ) - but most of the time I'm alone on the system.