Memory Leak/Management DB XML 2.1.8

> Hello,
>
>
>
> Seeing a memory leak.  Details included below:
>
>
>
> Problem Description:
>
>
>
> ¨       Database load utility uses increased amounts of memory  
> during lifetime of application.  Run top to track %CPU and %MEM for  
> the application.  The %MEM value increases at a rate that depends  
> on the cache size used to set up the database environment.  The  
> VIRTvariable (virtual memory) stays constant.
>
>
>
> Basic information:
>
>
>
> ¨       O.S. Fedora Core 3
>
> ¨       x86 architecture
>
> ¨       DB XML version 2.1.8
>
>
>
> DB XML Usage:
>
>
>
> ¨      Load database.
>
>
>
> Relevant Internal Data Classes:
>
>
>
> ¨       SqlThing class is responsible for forming XQuery statements  
> and executing them.  It joins an already existing database  
> environment as a client to execute XQuery against a container.
>
>
>
> ¨       The database environment is created/managed by another  
> class called EventDbEnvMgr.  The SqlThing class has a  
> EventDbEnvMgrmember object named edbem.  edbem creates XmlManager,  
> XmlUpdateContext, and XmlContainer pointer objects on the heap.  
> And the SqlThing object accesses two of these dereferenced pointers  
> through get() methods:
>
>
>
> o        edbem.getXmlCntr()                    // Gets dereferenced  
> edbem.XmlContainer
>
> o        edbem.getXmlUpdateCntxt()        // Gets dereferenced  
> edbem.XmlUpdateContext
>
> Code:
>
>
>
> ¨       The database environment is created by the following  
> EventDbEnvMgr method:
>
>
>
> void EventDbEnvMgr::createEnv()
>
> {
>
>          dbEnv dbe(0);
>
>
>
>          dbe.set_cachesize(0, 32*1024, 4);
>
>          dbe.set_lk_max_locks.(100000);
>
> dbe.set_lk_max_lockers.(100000);
>
> dbe.set_lk_max_objects.(100000);
>
>
>
>          try
>
>          {
>
>                      dbe.open(pathToEnv.c_str(), DB_CREATE |  
> DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_MPOOL | DB_INIT_TXN |  
> DB_RECOVER, 0);
>
>
>
>           } catch …
>
>
>
> }
>
>
>
> ¨       Client application calls insert() method within SqlThing  
> class numerous times to load database, one document at a time.  May  
> load up to 100K documents.  Documents are not large, and in fact  
> are fairly small.
>
>
>
> void SqlThing::insert(const char *Records)
>
> {
>
>          try
>
>          {
>
>                      std::string sContent(Records);
>
>                      //
>
>                      //  Exercises XmlContainer.putDocument() method.
>
>                      //
>
>                      edbem.getXmlCntr().putDocument
> (sInternalDocName.c_str(), sContent, edbem.getXmlUpdateCntxt(),  
> DBXML_GEN_NAME);
>
>
>
>           } catch …
>
> }
>
>
>
> ¨       Results:
>
>
>
> Observe that the Pmem value reported by top increases much faster  
> when I change the cache size like this:
>
>
>
> dbe.set_cachesize(0, 32*1024*1024, 4);  // Increased by a factor of 1K
>
>
>
> How do I plug the leak?  Can I flush the cache?  Is the leak within  
> one of the library objects? Or what?
>
>
>
> Can the leak be fixed with a patch without upgrading?
>
>
>
> Also, I exaggerated the locking configuration so that all the nodes/
> leafs can be accessed simultaneously with a database dump utility.
>
>
>
>
>
> Thanks,
>
>
>
> Mark Mason
>
> Senior Software Engineer
>
> General Dynamics
>
> Advanced Information Systems
>
> 210-442-4246
>
>
>
>