Bandwidth-Aware Scheduling of Workflow Application on Multiple Grid Sites

Listing 1

Parts of the source code showing how access to NWS is embedded in the Heft site-selector algorithm. We create a new Java class NwsAwareHeft for bandwidth-aware Heft site-selector algorithm. This listing shows only important fragments of modified or added part in the original Heft algorithm of Pegasus WMS. The added/modified code is shown in bold-face to distinguish it from the already available code in Pegasus WMS’s Heft class.

public class  NwsAwareHeft  extends Abstract {

 private NetworkInformationCollection mMachinesNIMap;

 private HashMap<String,String>  mGridSitesToMachinesMap;

 public void initialize  (  PegasusBag bag  )  {

  super.initialize  (  bag  );

  initializeNwsInformation  ();

  bag.add  (PegasusBag.NWS_INFO, mMachinesNIMap);

  bag.add  (PegasusBag.SITES_TO_MACHINES_MAP,

mGridSitesToMachinesMap);

  mHeftImpl  =  new Algorithm  (  bag  );

 }

 private void initializeNwsInformation  ()  {

  mMachinesNIMap=new NetworkInformationCollection  ();

  mGridSitesToMachinesMap=getGridSitesToMachinesMap  ();

  String

nwsNameServer=getNwsNameServerNameFromConfigFile  ();

  String     resources=getMachinesNames  ();

  mMachinesNIMap.init  (nwsNameServer, resources);

  mMachinesNIMap.performMeasurements  ();

 }

⋯

 private String getMachineName  (String gridSiteName)  {

  String machineName=“”;

  String urlPrefix=“”;

  SiteCatalogEntry scEntry=mSiteStore.lookup  (gridSiteName);

  if  (scEntry!=null)  {

   HeadNodeFS headNodeFS=scEntry.getHeadNodeFS  ();

   if  (headNodeFS!=null)  {

    FileServer fileServer  =

headNodeFS.selectStorageSharedFileServer  ();

    urlPrefix=fileServer.getURLPrefix  ();

    if   (urlPrefix!=null)  {

     machineName=parseMachineName  (urlPrefix);

    }

   }

  }

 return machineName

 }

⋯

}