I have a Codename One web-app that, after showing the logo, it remains completely blank and white for a variable time (from few seconds to more that ten seconds). My Internet connection is very fast (optical fiber).
Is there any tip to reduce the loading time of a Codename One web-app? The build size is 663kb and the generated application is 10,5MB (unzipped).
Chrome has some really nice benchmarking tools that help point out the time spent on each stage. You should run these and make sure that the downloaded binaries are gzipped so the download isn't the bottleneck.
Also make sure to run your tests against a deployed app and not on the preview which might exhibit different behavior.
In terms of the app, try to show a form quickly without any server requests or IO. Once you do that defer the code to the actual loading block later. If you trigger a server call this will significantly slow down loading.
Related
I have a BrowserComponent that loads a web page that does something by ajax every few seconds (suppose thirty seconds, I don't remember how many). These ajax requests get updates and keep the login.
My question is how to make the web page working when the app is in the background: sometimes the app works fine, other times it's killed by the o.s. when it's in the background (I suppose so because sometimes, when I reopen the app, it restarts).
There are apps that are never killed, such as media players, e-mail clients, etc.: how can I make my app always running in background? Of course I suppose that the CPU loading of my app is very low, but I didn't find any way to compare its cpu loading with other apps.
Thank you very much for any help.
You would find that hard to do with a web browser. Various OS's have different behaviors but even Android which used to be the least restrictive is moving towards a more restrictive background behavior to conserve battery life.
In the misc section of the developer guide we discuss the background modes e.g. background fetch etc.
You can do that from Codename One code which compiles to native but you can't leverage that from JavaScript as it doesn't give the OS enough control.
I found the first web page loading time for CN1 Javascript Built taking too long, need about 2 minutes.
I attached the Chrome's network loading screen shot, found the classes.js is the most heavy page, possible to zip it?
Second, there is 2 theme files that downloaded sequentially, is it possible for them to load at the same time?
Kindly advice.
Normally I would answer that you can look at the performance section of the developer guide but the relevant sections there relate to reducing the theme.res size which seems pretty small in your case.
The largest portion in your code is the class files so I'm guessing that the best way to reduce them is to further reduce dependencies so the obfucator can remove more dead code. Keep in mind that the classes.js file is cached and can be deployed via CDN's such as cloudflair to improve download speeds. It can be served in a gzipped form as well which is a part of the CDN repertoire.
I'm building a web application using GAE.
I've been doing some research by my own on GAE python project structures,
and found out that there isn't a set trend on how to place my handlers within the project.
As of now, I'm putting all the handlers(controllers) in main.py,
and make all urls (/.*) be directed to main.application.
Is this going to make my application slower?
Thank You!
In general, this will not make your application slower, however it can potentially slow you down your instance start-up time, but it generally isn't a problem unless you have very large complicated apps.
The instance start up time comes into play whenever GAE spins up a new instance for you. For example, if your app is unused for a long period and you start it up once in a long while, or for example, if your app is very busy and need a new instance to handle the load.
python loads your modules as needed. So if you launch an instance, and the request goes to main.py, then main.py and all the modules associated with it will get loaded. If your app is large, this may take a few seconds. Let's just say for example it takes 6 seconds to load every module in your app. That's a 6 second wait for whoever is issuing that request. Subsequent requests to that loaded instance will be quick.
It's possible to break down your handlers to separate modules. If handler for \a requires very little code, then having \a in a separate file will reduce the response time for \a. But when you load \b that has all the rest of the code, that would take a while to load. So it's possible to take that 6 second load and potentially break it up into a few requests that may take 2 seconds.
This type of optimization really depends on the libraries you need to load with each request. You generally want to do this later on, when you run into the problems, rather than design your layout for this purpose up front, since it's pretty difficult to predict.
App Engine warmup requests also help alleviate this problem.
No, that doesn't affect the speed. Your code needs to be loaded anyway, so it makes no difference if it's all in one file or not. It will of course make the file more complex, but that's your problem, not GAE's.
I am experiencing a performance bottle-neck in this website: http://oceanosdecolor.es/ and I'm not able to find it. If you try, you'll see any page (for example, homepage) takes a long time to load.
The first time you execute a page, the site reloads to detect client device, but that's only the first time and then it keeps client device so it doesn't reload again.
I log traces of the execution to database but I don't get useful information as, according to the log, the execution of the whole homepage happens in the same 1 second, but I can see that the homepage takes more time to load.
The IIS log (when trying locally) doesn't help as this also gives information in seconds, not miliseconds, and again, it says everything happens in the same second, and anyway running locally is much faster than on the server.
So, I ask for help in any tool to monitor performance with more accuracy or any technique I could use.
Thank you
I think your answer might not lie with IIS or SQL Server. According to the Developer Tools in Chrome, your actual page execution and sending out the HTML takes 400ms on first load from my location. The problem is you have a tangle of CSS files (many of which are not being found and causing extremely long delays). Also you have a lot of requests.
I would install Yahoo's YSlow for your favourite browser. This will give you a whole bunch of recommendations for what is running slow on your site from an end-user perspective.
To use the Developer Tools on Chrome: right click on your page, hit "Inspect Element" and then go to the "Network" tab and then hard-refresh your browser (shift-F5).
A few of the problems I see are: commun.css (2.5 seconds and failed), layout.css (400ms and failed), jquery-ui-1.8.10.custom.min.js (800ms and failed).
Find the reason for these failing and fix it and I'm sure your site will load faster. Also try use CSS image sprites wherever possible to cut down on the number of requests.
I'm working on a rather large classic asp / SQL Server application.
A new version was rolled out a few months ago with a lot of new features, and I must have a very nasty bug somewhere : some very basic pages randomly take a very long time to execute.
A few clues :
It isn't the database : when I run the query profiler, it doesn't detect any long running query
When I launch IIS Diagnostic tools, reqviewer shows that the request is in state "processing"
This can happen on ANY page
I can't reproduce it easily, it's completely random.
To have an idea of "a very long time" : this morning I had a page take more than 5 minutes to execute, when it normaly should be returned to the client in less than 100 ms.
The application can handle rather large upload and download of files (up to 2 gb in size). This is also handled with a classic asp script, using SoftArtisan FileUp. Don't think it can cause the problem though, we've had these uploads for quite a while now.
I've had the problem on two separate servers (in two separate locations, with different sets of data). One is running the application with good ol' SQL Server 2000 and the other runs SQL Server 2005. The web server is IIS 6 in both cases.
Any idea what the problem is or on how to solve that kind of problem ?
Thanks.
Sebastien
Edit :
The problem came from memory fragmentation. Some asp pages were used to download files from the server. File sizes could go from a few kb to more than 2 gb. These variations in size induced memory fragmentation. The asp pages could also take quite some time to execute (the time for the user to download the pages minus what is put in cache at IIS's level), which is not really standard for server pages that should execute quickly.
This is what I did to improve things :
Put all the download logic in a single asp page with session turned off
That allowed me to put that asp page in a specific pool that could be recycled every so often (download would now disturb the rest of the application no more)
Turn on LFH (Low Fragmention Heap), which is not by default on Windows 2003, in order to reduce memory fragmentation
References for LFH :
http://msdn.microsoft.com/en-us/library/aa366750(v=vs.85).aspx
Link (there is a dll there that you can use to turn on LFH, but the article is in French. You'll have to learn our beautiful language now!)
I noticed the same thing on a classic ASP + ajax application that I worked on. Using Timer, I timed the page load to be 153 milliseconds but in the firebug waterfall chart it randomly says 3.5 seconds. The Timer output is on the response and the waterfall chart claims that it's Firefox waiting for a response from the server. Because the waterfall chart also shows the response, I can compare the waterfall chart to the timer and there's a huge discrepancy 'every so often'
Can you establish whether this is a problem for all pages or a common subset of pages?
If a subset examine what these pages have in common, for example they all use a specific COM dll, that other pages don't.
Does this problem affect multiple clients or just a few?
IOW is there an issue with a specific browser OS version.
Is this public or intranet?
Can you reproduce the problem from a client you own?
Is there any chance there are some full-text search queries going on SQL Server?
Because if so, and if SQL Server has no access to internet, it may cause a 45-second delay every few hours or so when it tries to check the certifications (though this does not apply to SQL Server 2000).
For a detailed explanation of what I'm referring to, read this.
Are any other apps running on your web server? If so, is your problematic in the same app pool as any of them? If so, try creating a dedicated app pool for it. Maybe one of the other apps is having a problem and is adversely affecting yours.
One thing to watch out for is if you have server side debugging turned on in IIS, the web server will run in single threaded mode.
So if you try to load a page, and someone else has hit that url at the same time, you will be queued up behind them. It will seem like pages take a long time to load, but its simply because the server is doling out page requests in a single file line and sometimes you aren't at the front of the line.
You may have turned this on for debugging and forgot to turn it off for production.