Red Gate forums: ANTS Memory Profiler Previous Versions

RE: Failed to snapshot

Brian Donahue — Wed, 24 Oct 2012 11:28:19 GMT

I've never seen this problem before, but I'd try the advice in the error message from Windows. One or more .NET Framework components is probably corrupt of there are bad sectors on the disk. Windows is saying it believes there is a problem with the disk, evidenced by error code C0000185. So a chkdsk c: /F or a repair or reinstall of .NET Framework may be the way forward.

Failed to snapshot

kkchan — Tue, 23 Oct 2012 09:08:27 GMT

Hi
I am using ANTS memory profiler to profile my ASP.NET web app. However, I hit this error when I take snapshot. I am running under Windows 7 64 bits machine, however my web app pool is set "Enable 32 bits".

My web app is running fine if not launch from ANTS.

Please advice

Quote:

Windows cannot access the file C:\Windows\assembly\GAC_MSIL\System\2.0.0.0__b77a5c561934e089\System.dll for one of the following reasons: there is a problem with the network connection, the disk that the file is stored on, or the storage drivers installed on this computer; or the disk is missing. Windows closed the program IIS Worker Process because of this error.

Program: IIS Worker Process
File: C:\Windows\assembly\GAC_MSIL\System\2.0.0.0__b77a5c561934e089\System.dll

The error value is listed in the Additional Data section.
User Action
1. Open the file again. This situation might be a temporary problem that corrects itself when the program runs again.
2. If the file still cannot be accessed and
- It is on the network, your network administrator should verify that there is not a problem with the network and that the server can be contacted.
- It is on a removable disk, for example, a floppy disk or CD-ROM, verify that the disk is fully inserted into the computer.
3. Check and repair the file system by running CHKDSK. To run CHKDSK, click Start, click Run, type CMD, and then click OK. At the command prompt, type CHKDSK /F, and then press ENTER.
4. If the problem persists, restore the file from a backup copy.
5. Determine whether other files on the same disk can be opened. If not, the disk might be damaged. If it is a hard disk, contact your administrator or computer hardware vendor for further assistance.

Additional Data
Error value: C0000185
Disk type: 3

RE: Feature Request: Automatic Periodic Snapshots

jessica.ramos — Fri, 29 Jun 2012 16:40:47 GMT

Hello!

Yes, the snapshot API feature has been available since version 7.0 of the Memory Profiler. It's simple to use--just add a reference to RedGate.MemoryProfiler.Snapshot.dll and call RedGate.MemoryProfiler.Snapshot.TakeSnapshot() in your code as needed.

You can find more about it here: http://www.red-gate.com/supportcenter/content/ANTS_Memory_Profiler/help/7.4/amp_snapshot_api

RE: Feature Request: Automatic Periodic Snapshots

mwpowellhtx — Tue, 26 Jun 2012 18:58:18 GMT

This was posted a couple of years ago. Has there been any further movement on the automatic memory snapshot? and/or just how accessible is this feature in the API? I am taking a look at this for obvious reasons: to assess and hopefully arrest a serious memory "leak" (i.e. usage of static memory, stack, heap, etc).

RE: Error on "Take Memory Snapshot"

Adam Hodge — Tue, 06 Mar 2012 14:01:23 GMT

I am in the same boat! Any suggestions for Windows Server 2003?

RE: GC Root -- Yes Weak Reference Question

AndrewH — Mon, 06 Feb 2012 11:55:37 GMT

The message displays if the only reason the object is a GC root is that it's referenced by weak references, not if the only things that are referencing it are weak references. There would be no way to discover that an object has weak references pointing at

Weak references are confusingly named in a way: they aren't actually references at all. They work by creating a GC root for the object you specify. Unlike normal GC roots these don't force the object to stay in memory but just act as a placeholder. These aren't 'references' in the same way that assigning a variable creates a reference: it's two separate objects. One is usually (but not always!) a WeakReference object that knows about the GC root, and the other is the target object. 'Dereferencing' the weak reference involves looking up the object pointed to by the gc root.

Note that even with strong roots, there's no reason that an object which is a strong root can't have other references. If this were the case, you couldn't create a reference to an object stored in a static variable.

Also note that the WeakReference class isn't the only way to create a weak reference GC root: you can create them from unmanaged code, or using the GCHandle class.

The memory profiler won't show weak references in the object retention graph (as they aren't 'references' in the conventional sense), and won't count them in the distance to GC root column, so you can still use these to discover why the object is still in memory.

RE: GC Root -- Yes Weak Reference Question

hamishg — Thu, 26 Jan 2012 15:13:21 GMT

Hi,

I am not following this explanation for the following reasons:

1) Why would you ever see GC Root -- Yes Weak Reference... ? As you say, this should only be displayed if an object is only referenced via weak references. Now, if Ants Memory profiler does a force garbage collect before taking the snapshot, shouldn't these all be removed (since there are only weak references to it)?

2) You say if they are persisting, it's because they have a strong root of some kind. Now, according to what you said before, if this was the case, it shouldn't be listed as Yes - Weak Reference, as there is a strong reference to it.

I am quite confused about this.
Hamish

RE: Error on "Take Memory Snapshot"

Chris.Allen — Fri, 14 Oct 2011 15:45:05 GMT

If our current documentation is not working - would anyone be able to help us reproduce this exact issue in-house? If so, please contact support@red-gate.com directly. Thanks!

RE: Error on "Take Memory Snapshot"

RW — Wed, 05 Oct 2011 11:30:27 GMT

Hi,
Have u done the changes in Machine.config or ASPnet.config??
I am facing the same problem even after the change in ASPnet.config file.

Please reply. Thanks.

RE: Several questions about Memory Profiler

Brian Donahue — Thu, 11 Aug 2011 13:19:39 GMT

The answer is yes, it's just that simple. Once set of data is Profiler tallying up the size of the objects and the other is the performance counter data (nothing to do with us, it is generated by Windows) which includes all of the unmanaged resources, and ANTS is not capable of tracking those resources. In either case the data is not for all of .NET but the private bytes size in the performance counter includes the .NET runtime loaded into the process.

RE: Several questions about Memory Profiler

RinkeB — Thu, 11 Aug 2011 13:06:45 GMT

Quote:

No: private bytes includes free space on the .NET heaps as well as unmanaged memory usage. You can find out which is responsible by looking at the breakdown at the bottom of the snapshot summary page: the free space on all .NET heaps value is included in the private bytes.

So what explains the difference between the value in the line graph and the value in the summary box? The line graph includes all free space reserved by the whole of .NET?
I'm still quite confused about this. Sometimes the line graph value is twice as big as the summary value.
I hope you can give me some info on this, because i encounter this at all my MVC applications.

RE: Several questions about Memory Profiler

Brian Donahue — Fri, 05 Aug 2011 09:01:50 GMT

There is another discussion about the discrepancy here: http://www.red-gate.com/messageboard/viewtopic.php?p=33481#33481

RE: Several questions about Memory Profiler

RinkeB — Fri, 05 Aug 2011 07:30:34 GMT

Well, when I force a garbage collection by taking a snapshot, the counter decreases some, but there is still a big difference between the two numbers. This is the case for every MVC project I profile. Can I assume the counter is wrong for all projects of this kind or is there something else going on?

RE: Several questions about Memory Profiler

Brian Donahue — Thu, 04 Aug 2011 09:33:51 GMT

I think this is one of those cases where the performance counter is wrong because it doesn't update until after garbage collection.

RE: Several questions about Memory Profiler

RinkeB — Thu, 04 Aug 2011 09:22:39 GMT

Andrew is mostly talking about Virtual Bytes, which isn't the issue here I think.

I'm still wondering what's the difference between the the private bytes in the line graph (~50mb) and the private bytes on the top of the summary page (26,38mb).

picture

What does explain this difference?