We developed a Flutter windows desktop application for POS machines. One of the main feature is printing bills. We used https://pub.dev/packages/esc_pos_printer library which prints but, after printing 100+ bills the windows shows low memory alert and system hangs. While checking task manager it is found that committed memory use increases while printing and when it hits the maximum, system hangs. Please help to find a solution.
Related
Recently I start facing issue on few servers where CPU start consuming more resources than usual trend. I am trying to find out the root cause for this and took the dump of w3wp process from Task Manager(right click on process and took the dump).
Now the dmp file size is 14GB and I am trying to analyze it through WinDBG but the tool is not working and getting message:
I also took few minidumps but some of them opening fine while few are not so it's not related to confusion between 32bit or 64bit.(The collected dump is 64bit).
I am trying to know what causing this issue. Is it file size or I am not taking the dump properly.
I checked link but it's not helpful.
Windbg is not the right tool for this job. Dumps are only snapshots so you have no idea what happened before. Use ETW and here the CPU Sampling, which sums all calls and shows you in detail the CPU usage.
Install the Windows Performance Toolkit which is part of the Windows 10 SDK (V1607 works on Win8/8.1(Server2012/R2) and Win10 or the V1511 SDK if you use Windows 7/Server2008R2)), run WPRUi.exe and select CPU Usage
and press on Start. Capture 1-2 minutes of the high CPU usage and next click on Save. Open the generated ETL with WPA.exe (Perf analyzer), drag and drop the CPU Usage (Sampled) graph to the analysys pane
and load the Debug Symbols. Now select your process in the graph, zoom in and expand the stack, here you see the weight of the CPU usage of all calls
In this sample most CPU usage from Internet Explorer comes from HTML stuff.
For .NET applications WPA shows you .net related groupings like GC or JIT:
Expand the stack of the w3wp process to see what it is doing. From the names you should have a clue what happens.
When my Windows 10 app runs, it causes a process called Runtime Broker to execute, which takes up a lot of Memory space.
I know my app isn't "Memory-hungry" and it hardly takes 80 MB of RAM to execute. But from the time it starts, the Memory used by Runtime Broker keeps in increasing until the PC gets stuck.
Upon killing that process, the app is force closed by Windows.
I would have posted my source code here, if only I knew which part of the code is causing this to happen.
What are the possible technical reasons for this problem to happen, and what are the possible fixes in my code to prevent this?
Is there something wrong with my code, or is it some API that I am calling?
You can easily delete RuntimeBroker.exe and any other file. I deleted RuntimeBroker.exe and Livecomm.exe by booting a live Linux Dvd and after loading go and mount the c: drive then simply navigate to the file and delete it. Done!
Runtimebroker seems to hold about 60k per file held via StorageFile objects. It's still a bad problem and the only solution is to not hold on to very many of these.
Microsoft just never does anything about this.
Update: Microsoft seems to have quietly ditched UWP. The replacement has "WinUI" and is probably called the Windows App SDK at the moment. No more runtimebroker.exe.
I have an application that has 10000 threads running at a time. Each thread opens the same file. The problem is whenever I launch the application with 10K threads, the application terminates after creating 500 threads(file handles). I have tried the same application on Linux and is running fine after I tweaked the ulimit option. Is there any limit on the file handles a process can open in Windows? I have been googling and all I get is to change the entries in config.nt file in C\Windows\System32....
But I found out that the said file does not exist for 64 bit OS. Is there any way that I can change the limit in Windows?
My OS is WINDOWS 7 64 bit.
To view the total number of handles (not just file handles) your application opened at a given time: Just to make sure it's the handle limit.
Download Process Explorer from https://technet.microsoft.com/en-us/sysinternals/processexplorer.aspx
Make sure to set appropiate refresh speed.
Open it and go to View -> Select Columns -> press on the tab "Process Performance"and click on "Handle Count".
For Windows 7 x64 bit, a process can have 16.711.680 handles opened simultaneously.
If you want to check limits for yourself then read below.
Check that by using a tool from Windows Internals Book (https://technet.microsoft.com/en-us/sysinternals/bb963901.aspx). Tool's name is TestLimit and you will find it in the lower part of the page under the Book Tools header.
There are no ways to increase this limit for Windows Operating Systems as far as I know, and I looked also.
As others stated, think of a method to minimize the large number of threads.
Maybe your application closes the file, but not the handle.
My advice, if you really need using very large handle count, start a new process every time handle count is about 16m.
running out of Microsoft C runtime library file descriptors (Harry Johnston) appears to be the right diagnosis.
https://learn.microsoft.com/en-us/cpp/c-runtime-library/file-handling. The default max is 512 open file descriptors. The solution therefore is a line of code early in main:
_setmaxstdio(newmax);
How to do that in Python is another question.
I'm in need of help. The situation is the following:
We have a software that runs on Windows Mobile 5 and 6. It is deployed in around 15 cities on different devices (Motorola MC35, MC55, MC65, MC75, MC75A, ES400). It works perfectly fine everywhere except in one city. They have MC75A devices and every once in a while we get a helpdesk about our software disappearing from the device.
The most interesting part is when we log in to check the device, all we can see is a damaged/corrupted file system and the OS, which is set back to default.
We tried to reconstruct the problem here at our company, but we find it impossible. I'm wondering if anyone has ever bumped into this.
I'm gonna attach two images of the corrupted file system.
We use custom windows settings and AppCenter to protect the operating system from our customers. (They shouldn't be able to modify any settings on their own).
In general such corruption happens when the driver is interupted saving changes to the file system.
That can happen, for example, when a high priority thread consumes all cpu times.
It may also happen, when the device is hard reset, for example by taking the battery out during thed river is writing to the file system.
A low battery normally cannot result in that corruption:
a) as the device shuts down itslef with critcal battery power
and
b) the file system is in flash RAM (in contrast to Windows Mobile 2003 and before) and does not need battery power to hold data.
It is also possible that there is a bad behaving process doing these corruptions.
As you say you see this only in one city: What is the main difference with the devices there?
Are others also using the same device? Maybe the device series itslef or there firmware is faulty (contact symbol/motorola for new firmware or patches to the 'disk' driver)
Are the users in that area doing special things to the devices that others do not? For example remove the battery when they mean the device does not react?
Is the MC75A used in other areas and there it does not show the corruption?
You see, you have some more items to examine a rule for the corruption?
A couple of times recently I have noticed that 'something' is causing the Windows System Process to sit at 50+% and it will not quit until the PC is rebooted. Happening on Win2k and Win XP so far.
This is particularly troublesome because it currently appears to be triggered by MSVC 2005/Incredibuild and rebooting the build servers is not a nice thing.
At the same time the 'System Idle Process' process is holding the rest of the CPU and the build steps themselves seem to be starved. ie. a module that normally takes <5 minutes to compile is currently taking 20+.
I'd take a few guesses at maybe being virus checker or tortoise svn but would desperatly like some other suggestions.
Edit:
I've been experiencing this as something that is triggered, and the culprit may not be ongoing. Thats not to say that some other ongoing process hasn't done something 'stupid' and is managing an active lock up of System while appearing to be idle itself.
System (100% of 1 core), and System Idle Process are sharing 98-100% of the total CPU.
Occasionaly mt.exe, link.exe, buildservice would get a look in at 1-2%.
I'm running VNC to view the machine, so it's getting a look in on occasion.
Edit 2:
When left the previous evening the build process seemed to be progressing all be it slowly, but after waiting another 13 hours the 1 hour build process hasn't completed. System is still hogging the 1 core.
My understanding is that the "System" process is the time spent in the kernel (so performing disk I/O, network I/O (you did mention Incredibuild) and the like) -- I'd check for disk fragmentation, virus checkers and possibly look at these on other machines in your Incredibuild cluster.
As the System Idle process runs at "Low" priority, it's a red herring that it'd be "taking up CPU time" -- if anything it's just showing that there is available CPU time available. The fact the processing is stuck to a single processor shows that the process is doing something that is not multi-core aware, or someone has set it's thread affinity to 1.
I've noticed the virus checking software that I use can radically slow down compilation but it does not extend beyond the end of the build. Turning off advanced and heuristic checking improves this to the extent that I do not have to disable the scanner entirely. I have changed my scanning strategy such that I use scheduled full scans now more than advanced on the fly scanning, as it hurts the perfromance of a number of apps. (n.b. I am using the latest cut of Kaspersky). I'm also using an automated backup tool (AJCBackup) that also needs to be restrained when compiling.
You may also want to consider disableing the Windows Indexing service on drives that are be used to create a lot of temporary and object files, as it doesn't provide much value in this context for the amount of performance it draws.
Edit: Have checked which processes are actually hogging the CPU core and traced them back to a given app?
We've encountered issues with Kaspersky and Incredibuild in our offices - compiles and sometimes links will just hang and never finish.
Only seems to affect some machines though which is wierd, and only Windows XP (Vista seems immune from what I've seen).
Only solution I've found so far is to turn Kaspersky off entirely - so if you find a solution then let me know!
RE: smacl, work from the Windows Search/Indexing Service (WSearch) won't be attributed to the System process's CPU time, it should come from the SearchIndexer.exe/SearchFilterHost.exe services (Vista+).
The majority of activity from System you will see will be in disk activity from the lazy writer and other disk accesses. CPU activity from System will be because of kernel activity such as drivers (ISRs/DPCs) and other kernel-level filters (which could include AV file and process filters).
Process Explorer (http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx) can aid in viewing CPU usage across processes, including System. You can use the public Microsoft Symbol Server and this resource to get you started.
If you can take a trace with Xperf (http://msdn.microsoft.com/en-us/performance/cc825801.aspx), I can help you analyze where the CPU time is being spent in the System (kernel) context. Xperf isn't officially supported on XP, but you can take a trace on XP and analyze it on other systems.
Xperf and Process Explorer should be able to shine a spotlight on exactly the module(s) that are causing the runaway CPU usage. Symbols may not even be necessary to diagnose the problem; simply the module name can often point to the component in question that is slowing down your system. For example, high CPU usage from ndis.sys can point to network interrupts, or activity from modules such as aavmker4.sys can point to AV software (Avast! in this case).
And as always, check if there are any updated drivers and AV software for your system.
In my office, a conflict between Incredibuild and Spyware Doctor's Immunize feature caused similar issues. Turning off Immunize solved it for us.
What anti-virus/malware do you use?
I'm having same hangs when compiling using IncrediBuild in VS2003, on clean Windows 7 without any anti-virus. It worked fine on same box in XP and Vista.