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.
Related
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.
I'm inspecting a performance issue with an AngularJS application.
When performing specific actions, the CPU usage goes to 100%, the Chrome window freezes, and I have to manually terminate the process using Chrome's task manager.
I tried to debug the app (DevTools' Sources tab), but the application is quite large and the code is minified, which means that finding the issue won't be easy: I see a lot of code triggered by the digest cycle, and can't figure out which code is the actual culprit.
What could be helpful is to be able to profile the application once it freezes; I'm pretty sure the profiler will immediately show the actual bottleneck. I can successfully start the profiler (Performance tab) before the freeze happens, but once the application freezes, when I click on Stop button, the Loading profile window is stuck at zero percent (I waited for fifteen minutes just to be sure, it's still at zero), so I suppose that it's frozen as well.
Therefore my question is:
How do I find what causes the application to freeze when I'm unable to figure it out by simply debugging the application?
To answer my own question, the solution was to use a different browser. Surprisingly, Firefox let me profile the application during the freeze. The remaining part was easy, as I expected: by comparing the profiling results before the freeze with the ones after it, one could figure which code is executed repeatedly.
Thanks to Aleksey Solovey as well for his comment.
I was checking for XHR calls timing in Chrome DevTools to improve slow requests but I found out that 99% of the response time is wasted on content download even though the content size is less than 5 KB and the application is running on localhost(Working on my local machine so no Network issues).
But when replaying the call using Replay XHR menu, the Content download period drops dramatically from 2.13 s to 2.11 ms(as shown in the screen shots below). Data is not cached at browser level.
Example of Call Timing
Same Example Replayed
Can someone explain why the content download timing is slow and how to improve it?
The Application is an ASP.NET mvc 5 solution combined with angularJS.
The Web Server Details:
- Windows Server 2012 R2
- IIS 8
Thank you in advance for your support!
I can't conclusively tell you the cause of this, but I can offer some variables that you can investigate, which might help you figure out what's going on.
Caching
I know you said that the data is not getting cached at the browser level, but I'd suggest checking that again. Because the fact that the initial request takes 2s, and then the repeat request only takes 2ms really does sound like caching.
How to check:
Go to Network panel.
Look at Size column for the request. If you see from memory or from disk cache, it was served from the cache.
Slow development server or machine
My initial thought was that you're doing more work on your development machine than it can handle. Maybe the server requires more resources than your machine can handle. Maybe you have a lot of other programs running and your memory / CPU is getting maxed.
How to check:
Run your app on a more powerful server and see if the pattern persists.
Frontend app is doing too much work
I'm not sure this last one actually makes sense, but it's worth a check. Perhaps your Angular app is doing a crazy amount of JS work during the initial request, and it's maxing out your CPU. So the entire browser is stalling when you make the initial request.
How to check:
Go to Performance panel.
Start recording.
Do the action that causes your app to make the initial request.
Stop recording.
Check the CPU chart. If it's completely maxed out, then your app is indeed doing a bunch of work.
Please leave a comment and let me know if any of these helped.
I have also been investigating this issue on Chrome (currently 91.0.4472.164) as the content download times appear to be vastly different based on the context of the download. When going directly to a resource or attempting to update rendered content as the result of a web call, the content download time can take up to 10x the duration when made from other client applications or when simply saving the data off as a variable in Chrome.
I created a quick, hacky Spring Boot web application that demonstrates the problem that I have made public on github: https://github.com/zielinskin/h2-training-simple
The steps in the readme should hopefully be sufficient to demonstrate the vast performance differences.
I believe that Chrome will need to resolve this performance issue as it has nothing to do with the webserver or ui framework being used.
The "Content Download" includes both the time taken to download the content and also the time for the server to upload the content. You can test out the following cases to see what is the cause. Usually it is a combination of all them.
Case 1: server delay
Assume running server and client on localhost with 0 network delay, and small data.
time0 client receives a response with header content-length = 20
time5 server > client: 10 bytes of data
time5 client receives data
Case 2: network delay
Use hard-coded dummy data to speed up server
time0 client receives a response with header content-length = 20
time0 server > client: 10 bytes of data
time5 client receives data
Case 3: client is too busy
Isolate the query by trying something like curl google.com -v in terminal to access the URL directly. You can use Chrome Dev tool and Firefox Dev tools to copy the request as shown below.
Running WSo2 EMM 1.1.0, everything has been working just fine except for one big issue.
From the moment I first click on an app in the App Management tab, the WSO2EMM_DB.h2.db file starts to steadily grow as long as the server is running, even with absolutely no changes. Eventually, it gets so big that clicking an app on that tab takes a ridiculously long time to load the list of devices using the app. We're talking 5+ minutes, it becomes completely unusable. I have checked the error logs and found no errors at all, every time.
Restarting the server does nothing to correct the issue. Even if I click an app on the App Management tab once, and never again, the database file will continue to grow. Even restarting the server and not logging into the EMM page, it will continue to grow.
The only thing I've found so far that can possibly help is keeping backup copies of the database file and overwriting the current file when it gets too big. Obviously that's not a solution, as I'd need to create a new backup file every time there's a change on the server, and eventually the database file would grow too big from that too.
It's not an issue with the H2 database either. Not only have I tried starting over fresh several times and have had the same behavior, but here is the only info I could find regarding this issue, and they were having the issue regardless of whether or not it was on H2 or MySQL.
I've been trying to find a solution for this for over a month with no success. Any help would be appreciated!
EDIT: It looks like this might be the subject of EMM-826. Unfortunately there seems to be no response to that bug report so far.
EDIT 2: EMM-826 was closed with a message saying the following:
This issue is fixed in the EMM 1.1.0 GA latest pack. Please get all the patches for the product/build the product from the latest source [ https://github.com/wso2/product-emm ] and try again.
Unfortunately, that did not work for me. I'm not sure what exactly I'm doing wrong, so I'll list the what I did to try to fix it:
Downloaded the EMM 1.1.0 zip from http://wso2.com/products/enterprise-mobility-manager/.
Downloaded the zip from https://github.com/wso2/product-emm and pasted the files from that into my EMM_HOME directory.
When that didn't work, I searched for patches and found I was only using patches 1-6. In the documentation I found I could download patches 7-12 here. Patches 9 and 10 didn't work right for some reason; causing me not to be able to reach the EMM dashboard or publisher. I could only access the Carbon manager. I was able to make patches 7, 8, 11, and 12 work though - with no change in behavior.
Here are the steps I take to reproduce the issue:
After setting a fresh copy of the EMM up, I log in to the EMM dashboard as Admin, set up a user account, and upload an app through the Publisher.
Register a device to the user account I set up. In this case, an Android device running Android 4.2.2.
From the dashboard, I go to App Management and click the app I uploaded. The list of devices loads, but from that point on, the database file starts growing and eventually, after several hours, becomes so large it the device list will never load.
Please help!
Found this happening also, from a quick look it's the WSO2EMM_DB.notifications table. Seems to keep a history of all notifications over time, and the info for app installs is taken from non-optimized queries, which degrade as the table grows. You 'could' delete all rows from the table, and it will re-populate as devices 'check back' and report their info.
But you'd probably want to write a query to just keep the latest notification of each type of each user (I'll leave that to someone else...) and as was mentioned, it is apparently fixed in the latest version.
Issue appears to be resolved in EMM 2.0, which can be found here.
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.