qBittorrent is unstable with libtorrent 2.0

[DarkVoyage]

qBittorrent & operating system versions

qBittorrent: 4.5.1-4.5.2 x64
OS: Windows 11 Pro x64
Qt: 6
libtorrent: 2
RAM limit: default 512 MB
Torrents: over 25.000

What is the problem?

Quietly crashes after short period of work 1-2-3 hours, not longer. Lags a lot during switching between categories, was much faster at first glance. But can crash after any CPU and I/O consuming operation. After many crashes I decided to downgrade to libtorrent 1 version of 4.5.2 and it runs for half a day now. I will keep informed, if it will crash and how often.

The good thing I can remember about 4.4.5, while it was loading about 10 minutes or more in some times, it was stable and could run for weeks. 4.5.x series never ran a day without a crash, if I'm not mistaken. Not sure about 4.5.0 as it was impossible to work with for other reason.

I can say for sure that many torrents (big memory use) is the only key factor here. Same versions, but with Qt 5 ran for months on other machine that has only about 200 torrents, never crashed at all.

[ArcticGems]

No crash/stacktrace report?

Do you have the same issue with Qt 6 & 'libtorrent 1.2' (qBit version you use has libtorrent 2.0)??

[glassez]

RAM limit: default 512 MB
Torrents: over 25.000

Do you really expect that it could work stably with this layout?

[DarkVoyage]

No crash/stacktrace report?

It makes dumps at every crash, but I'm not going to share them publicly, because they contain torrent info.

Do you have the same issue with Qt 6 & 'libtorrent 1.2' (qBit version you use has libtorrent 2.0)??

Already wrote above that can't confirm yet, but it works more stable. Unfortunately I can't run for longer than a day for different reason. But this combination didn't crash yet. And also it lags even less.

Do you really expect that it could work stably with this layout?

Regarding libtorrent 2.0 #18540
No problem with 1.2. I can set more of course just to confirm that it works or crashes too. I will do.
And this also was not a problem in all previous qBt versions, they ran for months.
But before 4.5.0 I've installed RC versions.

[ArcticGems]

No crash/stacktrace report?

It makes dumps at every crash, but I'm not going to share them publicly, because they contain torrent info.

You could censor things like folder paths and 'torrent info'.

[DarkVoyage]

Dump file is binary. How can I edit it natively?
Actually I meant that I can send it personally to developer, who is going to check them, if there's any interest. Because some torrent might be the problem and there will a need to send problematic torrent file.

@glassez would you accept an archive of dumps?

[DarkVoyage]

Would this help? I've analyzed dmp file with WinDbg. If I can get anything else from it, instruct me.

*******************************************************************************
*                                                                             *
*                        Exception Analysis                                   *
*                                                                             *
*******************************************************************************
KEY_VALUES_STRING: 1
    Key  : AV.Dereference
    Value: NullClassPtr
    Key  : AV.Fault
    Value: Read
    Key  : Analysis.CPU.mSec
    Value: 1202
    Key  : Analysis.DebugAnalysisManager
    Value: Create
    Key  : Analysis.Elapsed.mSec
    Value: 109392
    Key  : Analysis.IO.Other.Mb
    Value: 0
    Key  : Analysis.IO.Read.Mb
    Value: 0
    Key  : Analysis.IO.Write.Mb
    Value: 54
    Key  : Analysis.Init.CPU.mSec
    Value: 77
    Key  : Analysis.Init.Elapsed.mSec
    Value: 38965
    Key  : Analysis.Memory.CommitPeak.Mb
    Value: 90
    Key  : Timeline.Process.Start.DeltaSec
    Value: 8216
    Key  : WER.OS.Branch
    Value: ni_release
    Key  : WER.OS.Timestamp
    Value: 2022-05-06T12:50:00Z
    Key  : WER.OS.Version
    Value: 10.0.22621.1
    Key  : WER.Process.Version
    Value: 4.5.2.0
FILE_IN_CAB:  qbittorrent.exe.5432.dmp
NTGLOBALFLAG:  0
APPLICATION_VERIFIER_FLAGS:  0
CONTEXT:  (.ecxr)
rax=0000000000000000 rbx=00007ffda791ee2d rcx=000000a2a97fd060
rdx=000000a2a97fec00 rsi=00007ff726a20000 rdi=0000000000000091
rip=00007ff726a2aec2 rsp=00007ff728712c60 rbp=000000a2a97fc670
 r8=000000a2a97fc8a0  r9=000000a2a97fc6c0 r10=00007ff726a2ac34
r11=00007ff728712c60 r12=0000000000000000 r13=000000a2a97fc170
r14=000000a2a97fefc0 r15=000000a2a97fc8a0
iopl=0         nv up ei pl nz na po nc
cs=0033  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00010204
qbittorrent+0xaec2:
00007ff7`26a2aec2 488b7808        mov     rdi,qword ptr [rax+8] ds:00000000`00000008=????????????????
Resetting default scope
EXCEPTION_RECORD:  (.exr -1)
ExceptionAddress: 00007ff726a2aec2 (qbittorrent+0x000000000000aec2)
   ExceptionCode: c0000005 (Access violation)
  ExceptionFlags: 00000000
NumberParameters: 2
   Parameter[0]: 0000000000000000
   Parameter[1]: 0000000000000008
Attempt to read from address 0000000000000008
PROCESS_NAME:  qbittorrent.exe
READ_ADDRESS:  0000000000000008 
ERROR_CODE: (NTSTATUS) 0xc0000005 - The instruction at 0x%p referenced memory at 0x%p. The memory could not be %s.
EXCEPTION_CODE_STR:  c0000005
EXCEPTION_PARAMETER1:  0000000000000000
EXCEPTION_PARAMETER2:  0000000000000008
STACK_TEXT:  
00007ff7`28712c60 00000000`00000000     : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : qbittorrent+0xaec2
SYMBOL_NAME:  qbittorrent+aec2
MODULE_NAME: qbittorrent
IMAGE_NAME:  qbittorrent.exe
STACK_COMMAND:  ~17s; .ecxr ; kb
FAILURE_BUCKET_ID:  NULL_CLASS_PTR_READ_c0000005_qbittorrent.exe!Unknown
OS_VERSION:  10.0.22621.1
BUILDLAB_STR:  ni_release
OSPLATFORM_TYPE:  x64
OSNAME:  Windows 10
IMAGE_VERSION:  4.5.2.0
FAILURE_ID_HASH:  {b959930f-ca78-78e8-bcc1-25cad8f7d2b1}
Followup:     MachineOwner
---------

[skjetne]

Keep having crashes as well ("not responding") but afaik I don't have any ram limits (it's currently chomping 6gb) and atm I only have 31 torrents.

[DarkVoyage]

This is still actual on 4.6.0 Alpha 1 with libtorrent 2.0. It worked about 2 days, but then exit without any messages.
I worked on version 4.5.2 with libtorrent 1.2 for several weeks. It never exits quietly the same way.
Trying 4.5.3 with libtorrent 1.2 (because 4.6.0 is not on allowlist at Redacted).

More than that 4.6.0 not only crashed silently, it hangs in memory as zombie with 1 mb working set memory, I can't kill it - no access. Will have to reboot.

[DarkVoyage]

Still actual on 4.5.5 lt2.0. Interface is almost unusable slow and after short time between some minutes or hours it silently crashes. At first run I thought it became better, it was working almost day long. I was adding more and more RAM limit to help with interface lagging (whiteout window and timeout). Then it crashed on a RAM overload (I have 64 GB, but Windows simply uses all space no matter what) with many software and then on each run it runs for some minutes and crashes. Returned to 4.5.5 qt6 lt1.2. As I told above, lt1.2 version runs for weeks without crashes. qB 4.5.4 ran for almost a month, I simply needed to change setup and stop it, it never crashes silently. lt2.0 is unstable for large torrent base. I hope that lt1.2 support would continue as long as possible in further versions.

[DarkVoyage]

@DarkVoyage Lowering file pool size to 500, 200 or 100 helps?

I will try, I have 10000. I will share config later.

[DarkVoyage]

lt1.2 can't be killed with any settings, it simply never crashes (at least since 4.x). lt2.0 never worked stable for me. Would be strange if any setting helps.

qBittorrent.zip

[DarkVoyage]

Changed file pool as offered above and 4.6.0 qt6 lt2.0 works for several days. I think that problem is no longer actual.