edu.isi.pegasus.planner.selector.replica

Class Default

java.lang.Object

edu.isi.pegasus.planner.selector.replica.Default

All Implemented Interfaces:

ReplicaSelector

Direct Known Subclasses:

Regex, Restricted

public class Default
extends Object
implements ReplicaSelector

The default replica selector that is used if non is specifed by the user. This gives preference to a replica residing on the same site as the site, where it is required to be staged to. If there is no such replica, then a random replica is selected.

In order to use the replica selector implemented by this class,

        - the property pegasus.selector.replica must be set to value Default, or
          the property should be left undefined in the properties.
 

Version:

$Revision$

Author:

Karan Vahi

Field Summary

Fields

Modifier and Type	Field and Description
private static String	FILE_URLS_PRIORITY_KEY
private static String	mDescription A short description of the replica selector.
protected edu.isi.pegasus.common.logging.LogManager	mLogger The handle to the logging object that is used to log the various debug messages.
protected edu.isi.pegasus.planner.common.PegasusProperties	mProps The properties object containing the properties passed to the planner.
private static String	NON_PREFERRED_SITE_PRIORITY_KEY
private static String	PREFERRED_SITE_PRIORITY_KEY

Fields inherited from interface edu.isi.pegasus.planner.selector.ReplicaSelector

LOCAL_SITE_HANDLE, PRIORITY_KEY, VERSION

Constructor Summary

Constructors

Constructor and Description
Default(edu.isi.pegasus.planner.common.PegasusProperties properties) The overloaded constructor, that is called by load method.

Method Summary

Modifier and Type	Method and Description
String	description() Returns a short description of the replica selector.
boolean	removeFileURL(edu.isi.pegasus.planner.catalog.replica.ReplicaCatalogEntry rce, String preferredSite, boolean allowLocalFileURLs) A convenience function that determines whether we should be removing a file URL from replica selection or not.
protected boolean	removeFileURL(String pfn, String site, String preferredSite, boolean allowLocalFileURLs) A convenience function that determines whether we should be removing a file URL from replica selection or not.
edu.isi.pegasus.planner.classes.ReplicaLocation	selectAndOrderReplicas(edu.isi.pegasus.planner.classes.ReplicaLocation rl, String preferredSite, boolean allowLocalFileURLs) This orders all valid location amongst all the locations returned by the Replica Mechanism.
edu.isi.pegasus.planner.catalog.replica.ReplicaCatalogEntry	selectReplica(edu.isi.pegasus.planner.classes.ReplicaLocation candidates, String preferredSite, boolean allowLocalFileURLs) This chooses a location amongst all the locations returned by the replica location service.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

mDescription

private static String mDescription

A short description of the replica selector.

mLogger

protected edu.isi.pegasus.common.logging.LogManager mLogger

The handle to the logging object that is used to log the various debug messages.

mProps

protected edu.isi.pegasus.planner.common.PegasusProperties mProps

The properties object containing the properties passed to the planner.

FILE_URLS_PRIORITY_KEY

private static final String FILE_URLS_PRIORITY_KEY

See Also:

Constant Field Values

PREFERRED_SITE_PRIORITY_KEY

private static final String PREFERRED_SITE_PRIORITY_KEY

See Also:

Constant Field Values

NON_PREFERRED_SITE_PRIORITY_KEY

private static final String NON_PREFERRED_SITE_PRIORITY_KEY

See Also:

Constant Field Values

Constructor Detail

Default

public Default(edu.isi.pegasus.planner.common.PegasusProperties properties)

The overloaded constructor, that is called by load method.

Parameters:

properties - the PegasusProperties object containing all the properties required by Pegasus.

Method Detail

selectReplica

public edu.isi.pegasus.planner.catalog.replica.ReplicaCatalogEntry selectReplica(edu.isi.pegasus.planner.classes.ReplicaLocation candidates,
                                                                                 String preferredSite,
                                                                                 boolean allowLocalFileURLs)

This chooses a location amongst all the locations returned by the replica location service. If a location is found with re attribute same as the preference pool, it is taken. Else a random location is selected and returned. If more than one location for the lfn is found at the preference pool, then also a random location amongst the ones at the preference pool is selected.

Specified by:

selectReplica in interface ReplicaSelector

Parameters:

candidates - the ReplicaLocation object containing all the pfn's associated with that LFN.

preferredSite - the preffered site for picking up the replicas.

allowLocalFileURLs - indicates whether Replica Selector can select a replica on the local site / submit host.

Returns:

ReplicaCatalogEntry corresponding to the location selected.

See Also:

org.griphyn.cPlanner.classes.ReplicaLocation

selectAndOrderReplicas

public edu.isi.pegasus.planner.classes.ReplicaLocation selectAndOrderReplicas(edu.isi.pegasus.planner.classes.ReplicaLocation rl,
                                                                              String preferredSite,
                                                                              boolean allowLocalFileURLs)

This orders all valid location amongst all the locations returned by the Replica Mechanism. The following ordering mechanism is employed - valid file URL's - all URL's from preferred site - all other URL's

Specified by:

selectAndOrderReplicas in interface ReplicaSelector

Parameters:

rl - the ReplicaLocation object containing all the pfn's associated with that LFN.

preferredSite - the preffered site for picking up the replicas.

allowLocalFileURLs - indicates whether Replica Selector can select a replica on the local site / submit host.

Returns:

ReplicaLocation corresponding to the replicas selected

removeFileURL

public boolean removeFileURL(edu.isi.pegasus.planner.catalog.replica.ReplicaCatalogEntry rce,
                             String preferredSite,
                             boolean allowLocalFileURLs)

A convenience function that determines whether we should be removing a file URL from replica selection or not. The file urls make sense only

      - if associated with the preference site or
      - if local File URL are allowed and rce is associated
        with local site
 

Parameters:

rce - the ReplicaCatalogEntry object.

preferredSite - the preferred site.

allowLocalFileURLs - indicates whether Replica Selector can select a replica on the local site / submit host.

Returns:

boolean

removeFileURL

protected boolean removeFileURL(String pfn,
                                String site,
                                String preferredSite,
                                boolean allowLocalFileURLs)

A convenience function that determines whether we should be removing a file URL from replica selection or not. The file urls make sense only

      - if associated with the preference site or
      - if local File URL are allowed and rce is associated
        with local site
 

Parameters:

pfn - the file url

site - the site associated with the pfn.

preferredSite - the preferred site.

allowLocalFileURLs - indicates whether Replica Selector can select a replica on the local site / submit host.

Returns:

boolean

description

public String description()

Returns a short description of the replica selector.

Specified by:

description in interface ReplicaSelector

Returns:

string corresponding to the description.