Sometimes Meteor screen freezes/cannot scroll - meteor

Sometimes, (more often than not), the browser screen freezes while navigating through a Meteor app. Basically everything works fine but I cannot scroll up or down.
There are no JS errors and everything seems to be running ok.
What could be causing htis?

This is often a hard thing to debug, but the first things I'd do are :
Disable your CSS (sometimes the silliest things can seem disasterous)
Check that there are no errors, in your terminal either (Meteor logs to the browser and terminal)
could you be flooding the front end with data? how big are your collections? are you using auto-publish or neatly crafted pub/subs?
What packages have you included in your project? try disabling any non essential packages
Install Kadira, and monitor your performance
Its really hard without more information, off the top of my head I imagine that you're either experiencing some weird styling / rendering issue, or that you're waiting on oversized subscriptions. Meteor overall should feel quite fluid and quick. I have a few questions :
Can you share more information about your app or where you're experiencing the issues you've described?
Is your project available anywhere?
What Browser are you viewing it in?
localhost or on a server? (if so what server environment?)

Related

(Client) screen capture in meteor?

Is there a way to get a screen capture (of the client screen) in meteor? I don't care whether it's available (once captured) on the client or the server - either is fine.
I saw something similar to this but it appeared to only work for a browser window. I'm looking for a screen capture of the client screen no matter what is active - even if there's no browser open - just as if the user hit the "PrntScrn" key then pasted into a jpg file and saved it somewhere.
One cannot do such things (calling unapproved OS functions) from code that runs inside of a web browser.
This is a deliberate design decision for web browsers, as one doesn't want scripts from the broader internet running arbitrary code on your computer.
Internet Explorer used to (not sure if still) provide "hooks" for Windows Update that involved an Active-X control that interacted with the OS.
They MADE the OS (Microsoft) so it was their prerogative, but it undoubtedly lead to some exploits...
You can use html2canvas for generating the screenshot. There is a meter package too for the same on atmospherejs. You can find the docs and examples here
Alternative is to use PhantomJS to do this job.

Intermittent / random disconnection from Firebase - everything stops working

I've search high and low for an answer, damn near going through every possible Firebase question on Stackoverflow. So here we go.
I have a webapp and cordova app that uses Firebase throughout. Everything works flawlessly, except occasionally the apps lose connection (usually after being in the background for a while) and everything stops working. No offline mode, no loading additional data, even Firebase.goOnline() doesn't kick it back in to gear. The only thing I can do is refresh the entire app and all is right in the world again.
But I can not for the life of me reproduce this on my own - it seems completely random.
Can anyone thing of any possible cause of this - or at least point me in a direction that I can keep trying to actively reproduce this?

Flex application suspended while in the background using Safari on Mac

Users of my Flex application report that sometimes the application is freezed when the browser window is minimized or they select another active tab over it. In this suspended state, the application receives no CPU share and all network connections it uses are closed. When the browser window is restored, the application is resumed. This happened with Safari 5 on Mac OS Leopard, with both Flash player 10.0 and 10.1. I searched a lot but I could not find any information about such behavior.
This behavior is not reproducible on each Mac with Safari, so my questions are:
Under which circumstances this may happen?
Is it possible entering in suspended state to be prevented and how?
Is it possible for the Flex application to be notified about going into sleep mode and wake up back?
This is a Safari thing and is by design. Newer versions of Safari suspend flash content that is not in the foreground tab (not sure when this started, version 4?) For instance, if you have multiple tabs open, each with a youtube video playing and you go back and forth between the tabs, only one of the videos will be playing at a time. To answer your specific questions:
This will happen to any flash content that is in a background tab (not sure about the minimized state.)
Not aware of a means of disabling this behavior.
You may want to dig around in the Safari documentation to see if there is some sort of JavaScript event that you can grab onto, but I don't think you are likely to have success there.
Good luck.
Are your users using Flash Player 10.1 ? As part of the performance improvements in 10.1; I believe an application in a minimized state will get throttled in order to use less system resources / battery power.
I don't think there is any way to prevent this; and no APIs exposed that relate to this.
Other people I've spoken to have had issues with using local connections between minimized apps and active apps. I'd bet there is already a bug in the bug base on that.
Wrt the following above:
.I don't think there is any way to prevent this; and no APIs exposed that relate to this.
You may want to check out if Silverline from Librato can help you control how much and which applications get what system resources (CPU, memory, Disk and Network IO) with dynamic control based on application demand. If the above issue is a feature of flash - then obviously it may not help. But if you are trying to say run multiple applications / processes and would like to control who gets how much system resources (dynamically) then you could try Silverline - it does not require any changes to OS or app. http://silverline.librato.com

Inaccurate progress bar when uploading large files using ASP.NET and Uploadify? [duplicate]

The file upload script I wrote early last year for an internal website has been misbehaving oddly on a number of machines. On some machines it consistently works fine, on others it consistently misbehaves. I am having exactly the same problem with YUI Uploader, SWFUpload (2.2 and 2.5a), and Uploadify.
On the misbehaving machines, the progress event (or callback as the case may be) is reporting the upload going far too quickly. It is progressing around 9 or 10MB/s, instead of the 50 or 60kb/s that is actually going on. The progress bar fills up very quickly, and then no more progress events are triggered. A few minutes later the completion event will trigger when the upload is actually done.
I must emphasize that the file upload does proceed normally, even though the progress being reported is very wrong.
The progress events are reporting a correct file size, but the reported amount uploaded is usually way too high, and it appears that it is always a multiple of 2^16 (65536).
I'm only having this problem with Firefox 3.5 on Windows XP, all of which have various subversions of Flash 10.
Has anyone heard of this happening, or have any idea what is going on?
(I'm off to go file a number of bug reports, but hopefully someone here has some previous experience with this.)
Turns out it was AVG that was proxying the requests. As far as the Flash was concerned it was uploading it very very quickly... into AVG. AVG then proceeded to upload in the background.
It seems like this is a general XP issue with AVG's Link Scanner service. I turned off all options of the Link Scanner in AVG and Flash upload progress (at least through the YUI 2 Uploader) seems to be reporting accurately.

Why is my swf causing the Flash Player to crash

I've got a flex-based swf, which is loading an AS 2-based swf and then, negotiating further activity via a LocalConnection.
From time to time, the AS 2-swf can request that the flex-based swf load a movie.
I've arranged this via on(release){} functions.
The AS 2-swf, I'm making in Swish Max. In Swish, when i set the on (release) on a text field, (to invoke .send() on my localconnection), it works splendidly. However, when I attempt to perform the same calls for an on(release) attached to a movieclip, it actually causes the Flash player, and even the browser plugin to crash.
In fact, the browser (IE) crashes as well.
I checked the debug trace that ie asked me to send to microsoft at the last IE crash, and i noticed a StackOverflow exception embedded deep in the trace, but I couldn't determine its source.
Can you help me understand what's going on here?
Are you having more than one LocalConnection connect to the same channel? This will cause the browser to crash.
Are you sending lots of requests at the same time, this will make it crash, and some browsers are more sensitive for those things than other.
This earlier post might have some helpful tips for you.
That's a wrong way to debug your application. Use your Flex Builder's debugging tool instead. You tend to lay blame on LocalConnection as it is the most complex part of the operation, when it could just as easily be an infinite loop.
You don't seem to be using the right tools either. I'd trust FF's FireBug over IE's dump. Besides, we'll need to see some more code before we can accurately tell you what's wrong.
Are you sure the crash is not only in your computer? Try running the FlashUtil??.exe at \WINDOWS\system32\Macromed\Flash\ to fix/update the Flash installaction. There are some known issues that corrupt Flash installation so it become unstable when using some objects.

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