Re: Ineeficient Memory Usage

Tech-Archive recommends: Fix windows errors by optimizing your registry

Michael,
I have similler issue with the MSXML parser with Visual Studio. Here I have
a sample code. Can you run this and see you find any thing worng with my code.

thanks in advance.


#include "stdafx.h"
#include <msxml2.h>
#include "comutil.h"
#include "psapi.h"

void Init();
void Release();
BOOL LoadXML(LPSTR lpzxml);
BOOL Go_To_Parent(LPCSTR lpszNodeName);
BOOL GetChild(LPCSTR lpszNodeName, LPCSTR lpszNodeValue);
void PrintMemoryInfo( DWORD processID, int Iteration );

IXMLDOMDocument2 *pXMLDom;
IXMLDOMNode *pNode;



int _tmain(int argc, _TCHAR* argv[])
{

LPSTR lpzxml =
"<PromptDataRoot><Errors>OK</Errors><NodeId>3</NodeId><Action></Action><SessionDataRoot><SessionId>00105062517143200002</SessionId><DateTime>6/25/2005
5:14:37
PM</DateTime><CurrentDataItem>TNI</CurrentDataItem><LookupUserInputKey>1</LookupUserInputKey><DataCollected><InitialUserKey>1</InitialUserKey><LANGUAGECHOICE>1</LANGUAGECHOICE></DataCollected><StepLog><PromptData><NodeId>2</NodeId><UserInputKey>1</UserInputKey><LookupKey>1</LookupKey></PromptData><Action></Action></StepLog></SessionDataRoot><PromptControlData><Language>0</Language><MainMessage><MsgId>!102</MsgId><ReplayMsgKey></ReplayMsgKey><CorrectValues></CorrectValues><CharSet>0123456789</CharSet><Length>10</Length><Timeout>10000</Timeout><TimeOutMsgId>!102</TimeOutMsgId><RetryCount>3</RetryCount><RetryExitAction><Transfer></Transfer><End>N</End></RetryExitAction><RetryExitMsgId>!125</RetryExitMsgId></MainMessage><ConfirmMessage><MsgId>!103
^# !104</MsgId><CorrectValues>1,2
</CorrectValues><CharSet></CharSet><Length>1</Length><Accept>1</Accept><Reject>2</Reject><Timeout>10000</Timeout><TimeOutMsgId>!103
^#
!104</TimeOutMsgId><RetryCount>2</RetryCount><RetryExitAction><Transfer><Record>N</Record><Phone>2003207</Phone><BusyAction>End</BusyAction><BusyMsgId>!123</BusyMsgId></Transfer><End>N</End><CompletionStatus>1</CompletionStatus></RetryExitAction><RetryExitMsgId>!126</RetryExitMsgId></ConfirmMessage></PromptControlData><SpecialProcessing><MiscMessageIdTags></MiscMessageIdTags></SpecialProcessing></PromptDataRoot>";
char szValue[512];
DWORD x;
for(int i = 0 ;i<1000;i++)
{
Init();
LoadXML(lpzxml);
Go_To_Parent("PromptDataRoot");
GetChild("Errors", szValue);
Release();
x = GetCurrentProcessId();
PrintMemoryInfo(x, i);

Sleep(10000);
}

MessageBox(NULL, "Done", "Info", MB_OK);


return 0;
}



void Init()
{

CoInitialize(NULL);
CoCreateInstance(__uuidof(DOMDocument40),
NULL,
CLSCTX_INPROC_SERVER,
__uuidof(IXMLDOMDocument2),
(void**)&pXMLDom);

pXMLDom->put_async(VARIANT_FALSE);
pXMLDom->put_validateOnParse(VARIANT_FALSE);
pXMLDom->put_resolveExternals(VARIANT_FALSE);


}
void Release()
{

if (pNode)
pNode->Release();
if (pXMLDom)
pXMLDom->Release();

CoUninitialize();

}
BOOL LoadXML(LPSTR lpzxml)
{
VARIANT_BOOL status;
BSTR bstrXML;

try{

bstrXML = _bstr_t(lpzxml);
pXMLDom->loadXML(bstrXML, &status);
return TRUE;
}

catch(...)
{
return FALSE;
}
}

BOOL Go_To_Parent(LPCSTR lpszNodeName)
{

IXMLDOMElement *pElementRoot;
IXMLDOMNodeList *pNodeList;
BSTR bstrValue;
long lNodeLength;

try{
pXMLDom->get_documentElement(&pElementRoot);
pElementRoot->getElementsByTagName(_bstr_t(lpszNodeName), &pNodeList);
pNodeList->get_length(&lNodeLength);
if (lNodeLength > 0)
{
pNodeList->get_item(0, &pNode);
return TRUE;
}
else
{
pXMLDom->get_childNodes(&pNodeList);
pNodeList->get_item(0, &pNode);
pNode->get_xml(&bstrValue);
return TRUE;
}

}

catch(...)
{
return FALSE;
}


}

BOOL GetChild(LPCSTR lpszNodeName, LPCSTR lpszNodeValue)
{
BSTR bstrValue;
long lLength, l;
IXMLDOMNodeList *pNodeList;
IXMLDOMNode *pLocalNode;
try{
pNode->get_childNodes(&pNodeList);
pNodeList->get_length(&lLength);
for (l=0;l <=lLength;l++)
{
pNodeList->get_item(l, &pLocalNode);
pLocalNode->get_xml(&bstrValue);
pLocalNode->get_nodeName(&bstrValue);
if (strcmp((LPSTR)_bstr_t(bstrValue), lpszNodeName) == 0)
{
pLocalNode->get_text(&bstrValue);
sprintf((char *)lpszNodeValue, "%s", (LPCSTR)_bstr_t(bstrValue));
return TRUE;
pNodeList->Release();
pLocalNode->Release();
}

}
return FALSE;
}

catch(...)
{
return FALSE;
}


}


void PrintMemoryInfo( DWORD processID, int Iteration )
{
HANDLE hProcess;
PROCESS_MEMORY_COUNTERS pmc;

TCHAR szProcessName[MAX_PATH] = TEXT("<unknown>");

hProcess = OpenProcess( PROCESS_QUERY_INFORMATION |
PROCESS_VM_READ,
FALSE, processID );
if (NULL == hProcess)
return;

HMODULE hMod;
DWORD cbNeeded;

if ( EnumProcessModules( hProcess, &hMod, sizeof(hMod),
&cbNeeded) )
{
GetModuleBaseName( hProcess, hMod, szProcessName,
sizeof(szProcessName)/sizeof(TCHAR) );
}


if ( GetProcessMemoryInfo( hProcess, &pmc, sizeof(pmc)) )
printf( "Iteration :%d, ProcessName :%s, PID:%u, Memory Usage:%dk
\n",Iteration, szProcessName, processID ,pmc.WorkingSetSize/1024);


CloseHandle( hProcess );
}










"Michael Rys [MSFT]" wrote:

> A repro is a T-SQL script, data and (if necessary) some code that shows the
> behaviour so we can try to run it in our environment to see whether we can
> find the reason for the behaviour (as per email exchange).
>
> Best regards
> Michael
>
> "TomPearson" <TomPearson@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
> news:567A03AE-AEF4-4147-A39E-6D2F9EADB4E3@xxxxxxxxxxxxxxxx
> >I have tried this in isolation without any other db queries, processes etc
> > going on and the result is the same. No temp tables are used during this
> > task.
> >
> > I would be eager to have someone look into the problem, but I don't
> > understand what you mean by a repro I'm afraid.
> >
> > Cheers
> > Tom
> >
> >
> > "Michael Rys [MSFT]" wrote:
> >
> >> Hi Tom
> >>
> >> This is the right newsgroup. But since it is a newsgroup, it may take a
> >> while until your posting gets distributed and people answer.
> >>
> >> There are lots of reasons why this may happen, including a problem with
> >> SQL
> >> Server. Are there any other processes going on in the database that may
> >> use
> >> up memory and resources (other queries, allocating temp tables etc)?
> >>
> >> Can you send us a repro, so that we can investigate it in our lab to see
> >> whether it repros and if, why?
> >>
> >> Thanks
> >> Michael
> >>
> >> "TomPearson" <TomPearson@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
> >> news:7F720240-6B2A-414F-8296-1025383DB57C@xxxxxxxxxxxxxxxx
> >> > Have I posted this in the wrong place?
> >> > I had hoped for some replies by now.
> >> >
> >> > If my wording is poor or unclear I am will hapily clarify as I could
> >> > really
> >> > do with some advice on this issue.
> >> >
> >> > Also don't be afraid to state the obvious as I may have missed
> >> > something
> >> > really simple.
> >> >
> >> > Cheers
> >> > Tom
> >> >
> >> > "TomPearson" wrote:
> >> >
> >> >> I have an instance of SQL Server 2000 (SP4) running on Win 2K.
> >> >> On it I have a task that runs to decompose xml into tables using
> >> >> sp_prepare/sp_remove xml doc procedures and open xml.
> >> >>
> >> >> When the server is booted or sql server and sql server agent process
> >> >> restarted it sits happily using about 60MB of memory. However once I
> >> >> start my
> >> >> xml decomposition task the memory gradually creeps up until it hits
> >> >> the
> >> >> maximum.
> >> >> Now I know SQL server will effectively grab all the memory it can and
> >> >> keep it.
> >> >> However my issue is not with the amount of memory it has taken, but
> >> >> the
> >> >> way
> >> >> it would appear to use it.
> >> >>
> >> >> This is because when the task first kicks off it runs like grease
> >> >> lightening
> >> >> and will decompose about 1000 1MB XML files a minute. However once the
> >> >> memory
> >> >> has reached maximim this is down to 1 1MB XML file a minute. Quite a
> >> >> significant difference despite the file being indetical in structure
> >> >> (they
> >> >> are messages with different content).
> >> >>
> >> >> I have tried to use profiler to determine where the problem is, but it
> >> >> looks
> >> >> most likely that sql server is not releasing enough unused memory back
> >> >> to
> >> >> itself. The overhead is in the passing of large chunks of data between
> >> >> stored
> >> >> procedures and the use of the xml (sp_prepare and sp_remove) and this
> >> >> is
> >> >> only
> >> >> a significant overhead once SQL Server has taken all the memory for
> >> >> itself.
> >> >> Also once the task is stopped at no point is memory ever released by
> >> >> SQL
> >> >> Serevr even if there is no activity at all for hours/days.
> >> >>
> >> >> Is this a known issue/bug or is it possible that I have done something
> >> >> wrong?
> >> >> Note sp_remove is always called after an sp_prepare so I assume that
> >> >> this
> >> >> should unallocate any memory used by that.
> >> >>
> >> >> Alternatively if a parent procedure runs continually calling the same
> >> >> child
> >> >> procedure, do the variables local to the child procedure get cleared
> >> >> properly
> >> >> between each call if the parent is still active?
> >> >>
> >> >> I'm very perplexed and would greatly appreciate some assistance/ideas
> >> >>
> >> >> Cheers
> >> >> Tom
> >> >>
> >>
> >>
> >>
>
>
>
.

Relevant Pages