app get hanged(dire need of help)

friends,

       app polling vm history points every 5 minutes. For this we are using vim25.jar(vsphere sdk 4.1 version) to get vm history report. Its running for 3 to 4 hours succesfully. Then it gets hanged while we call  "retrievePropertiesAllObjects" method . Please help me to get out this issue.

It's getting hanged after 2 to 3 hours in the below code,

RetrieveResult rslts = vimPort.retrievePropertiesEx(
                    propCollectorRef, listpfs, propObjectRetrieveOpts);

Thanks,

Alagammal.A