Windows Server 2012

Memory dump after a clean zabbix_agentd start and running the powershell script (100 iterations of 4 times wmi.get) (Powershell script result: Start: 4400, end: 5824 kb, delta: 1424 kb)

Tested on 2.4.1, issue still exists. (Start: 4296, end: 5644 kb, delta: 1348 kb)

Can someone take a look at this? We can't deploy the agent until this is fixed...

Hi,

I looked at the code and there are at least 1 pointer that is never released (pclsObj).
Think thats the source of the memory leak.

I spend some time and rebuild completely the source code of wmi.cpp.
Also it now supports WMI arrays. Very usefull to get HP operational status info:
wmi.get[root\hpq,SELECT OperationalStatus FROM HP_ComputerSystem]

Attached the 2 files. My wmi.cpp and the 32 bits agent already compiled.

Can someone test if the memory leak is still there?

pintonunes, can you add your modifications in form of a patch/unidiff please?

Marc, just replace the current wmi.cpp with the one in attach and compile.
If you really need the patch file let me know.

pintonunes, it's just good practice and is easier to merge for devs - especially when merging with a different/newer code base.

Marc, i will.. just finishing the all code. Add log lines, etc etc..
I am running this agent for 2 days in about 10 servers and the agent stabilized at 11Mb of RAM usage.

Marc, attached the last wmi.cpp. The other one had some bugs.
Unfortunately i dont know how to build a patch file with visual studio 2010 express.
But like i said, its just a matter of replacing the current wmi.cpp file.

Pedro, your fix in wmi.cpp does two things: (a) it fixes a memory leak and (b) introduces support for arrays. Could you please add your array patch to ZBXNEXT-2459, but reattach wmi.cpp here that only fixes the memory leak in the original code? The memory leak fix can be merged rather quickly, while the array support has to be extensively tested and is a slower process.

Attached the wmi.cpp without array support.
The code is actually pretty diferent from the original one.
2 things about it:

• extern "C" void zbx_co_uninitialize(){} is not needed but you need to remove it from zabbix_agentd.c
• static CoCreateInstanceGuard ccig; is static so WMI is initialized when agent starts which makes it dependent on the WMI windows service. If WMI service restarts you need to restart zabbix agent also. It can be changed to non static easly.

Regards

Pedro, I have narrowed the fix regarding the memory leak in your patch to just the following:

$ svn di -c 50877
Index: src/libs/zbxsysinfo/win32/wmi.cpp
===================================================================
--- src/libs/zbxsysinfo/win32/wmi.cpp   (revision 50876)
+++ src/libs/zbxsysinfo/win32/wmi.cpp   (revision 50877)
@@ -216,6 +216,9 @@
 out:
        VariantClear(&vtProp);
 
+       if (0 != pclsObj)
+               pclsObj->Release();
+
        if (0 != pEnumerator)
                pEnumerator->Release();

This seems to fix the leak, which is the main topic in this issue. If you feel there is something else to fix like not properly handling WMI service restarts, please register a new ZBX.

Memory leak fix is available in development branch svn://svn.zabbix.com/branches/dev/ZBX-8506 .

Yes, that the obvious fix using the existing code.
COM objects should use RAII to create and release resources, etc etc...
Anyway, thanks for the fix

Unfortunately ATL is not available in Visual Studio Express editions or Windows SDK. So we had to do it the hard way.

Successfully tested

Fixed in pre-2.2.8 r51003, pre-2.4.3 r51004, and pre-2.5.0 (trunk) r51005.

Issue regarding WMI service restarts has been reported separately in ZBX-9112.

Pedro, as stated in ZBX-9112, problem with WMI service restarts was not observed. If you have any information on how to reproduce the issue, please add a comment to ZBX-9112.

pintonunes, regarding:
Unfortunately i dont know how to build a patch file with visual studio 2010 express.

I don't know whether there is a build-in functionality to create proper patches in Visual Studio 2010 Express, but you could give it a try to do it the UNIX way.
See: http://sourceforge.net/projects/unxutils/

C:\TEMP\zabbix-2.2.7>diff.exe -u src\libs\zbxsysinfo\win32\wmi.cpp.orig src\libs\zbxsysinfo\win32\wmi.cpp > zbx8506.patch

When will be zabbix agent 2.5 available for windows?