edu.isi.pegasus.planner.selector.replica
Class Restricted

java.lang.Object
  edu.isi.pegasus.planner.selector.replica.Default
      edu.isi.pegasus.planner.selector.replica.Restricted

All Implemented Interfaces:

ReplicaSelector

public class Restricted
extends Default

A replica selector, that allows the user to specify good sites and bad sites for staging in data to a compute site.

A good site for a compute site X, is a preferred site from which replicas should be staged to site X. If there are more than one good sites having a particular replica, then a random siteis selected amongst these preferred sites.

A bad site for a compute site X, is a site from which replica's should not be staged. The reason of not accessing replica from a bad site can vary from the link being down, to the user not having permissions on that site's data.

The good | bad sites are specified by the properties pegasus.selector.replica.*.prefer.stagein.sites| pegasus.selector.replica.*.ignore.stagein.sites, where the * in the property name denotes the name of the compute site. A * in the property key is taken to mean all sites.

The pegasus.selector.replica.*.prefer.stagein.sites property takes precedence over pegasus.selector.replica.*.ignore.stagein.sites property i.e. if for a site X, a site Y is specified both in the ignored and the preferred set, then site Y is taken to mean as only a preferred site for a site X.

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

        - the property pegasus.selector.replica.selector must be set to value Restricted.
 

Version:

$Revision: 2572 $

Author:

Karan Vahi, Gaurang Mehta

Field Summary

private static String	mDescription A short description of the replica selector.
private Set	mGlobalIgnoredSites The Set of ignored sites, that are ignored for selecting replicas for all sites.
private Set	mGlobalPreferredSites The set of preferred sites, that are preferred stagein sites for all sites.
private Map	mIgnoredSitesMap A Map indexed by site handles, that contains a set of site handles.
private Map	mPreferredSitesMap A Map indexed by site handles, that contains a set of site handles.
private static String	PROPERTY_IGNORE_SUFFIX The property suffix for determining the ignored sites for a site x.
private static String	PROPERTY_PREFER_SUFFIX The property suffix for determining the preferred sites for a site x.
private static String	PROPERTY_PREFIX The property prefix for all properties used by this selector.

Fields inherited from class edu.isi.pegasus.planner.selector.replica.Default

FILE_URL_SCHEME, mLogger, mProps

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

LOCAL_SITE_HANDLE, VERSION

Constructor Summary

Restricted(PegasusProperties properties)
The overloaded constructor, that is called by load method.

Method Summary

String	description() Returns a short description of the replica selector.
protected String	getProperty(String site, String suffix) Returns the name of the property, for a particular site X.
private Set	getSitesSet(String value) Returns a set of third party sites.
protected boolean	globallyIgnored(String site) Returns a boolean indicating whether a site is to be ignored as a replica source for all compute sites.
protected boolean	globallyPreferred(String site) Returns a boolean indicating whether a site is a preferred replica source for all compute sites.
protected boolean	ignore(String source, String destination) Returns a boolean indicating whether a source site is to be ignored for staging to a destination site
private void	populateSiteMaps(String site) Builds up the set of preferred and ignored sites for a site.
protected boolean	prefer(String source, String destination) Returns a boolean indicating whether a source site is to be preffered for staging to a destination site
ReplicaCatalogEntry	selectReplica(ReplicaLocation rl, String preferredSite, boolean allowLocalFileURLs) This chooses a location amongst all the locations returned by the replica location service.

Methods inherited from class edu.isi.pegasus.planner.selector.replica.Default

removeFileURL, removeFileURL, selectReplicas

Methods inherited from class java.lang.Object

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

Field Detail

mDescription

private static final String mDescription

A short description of the replica selector.

See Also:

Constant Field Values

PROPERTY_PREFIX

private static final String PROPERTY_PREFIX

The property prefix for all properties used by this selector.

See Also:

Constant Field Values

PROPERTY_PREFER_SUFFIX

private static final String PROPERTY_PREFER_SUFFIX

The property suffix for determining the preferred sites for a site x.

See Also:

Constant Field Values

PROPERTY_IGNORE_SUFFIX

private static final String PROPERTY_IGNORE_SUFFIX

The property suffix for determining the ignored sites for a site x.

See Also:

Constant Field Values

mPreferredSitesMap

private Map mPreferredSitesMap

A Map indexed by site handles, that contains a set of site handles. The sites in the set are the sites from which to prefer data transfers to the site referred to by key of the map.

mGlobalPreferredSites

private Set mGlobalPreferredSites

The set of preferred sites, that are preferred stagein sites for all sites. Referred to by "pegasus.selector.replica.*.prefer.sites" property.

mIgnoredSitesMap

private Map mIgnoredSitesMap

A Map indexed by site handles, that contains a set of site handles. The sites in the set are the sites from which to ignore data transfers to the site referred to by key of the map.

mGlobalIgnoredSites

private Set mGlobalIgnoredSites

The Set of ignored sites, that are ignored for selecting replicas for all sites. Referred to by "pegasus.selector.replica.*.default.sites" property.

Constructor Detail

Restricted

public Restricted(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 ReplicaCatalogEntry selectReplica(ReplicaLocation rl,
                                         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

Overrides:

selectReplica in class Default

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:

ReplicaCatalogEntry corresponding to the location selected.

See Also:

org.griphyn.cPlanner.classes.ReplicaLocation

description

public String description()

Returns a short description of the replica selector.

Specified by:

description in interface ReplicaSelector

Overrides:

description in class Default

Returns:

string corresponding to the description.

prefer

protected boolean prefer(String source,
                         String destination)

Returns a boolean indicating whether a source site is to be preffered for staging to a destination site

Parameters:

source - the source site.

destination - the destination site.

Returns:

true if source is a preferred site for staging to destination, else false.

ignore

protected boolean ignore(String source,
                         String destination)

Returns a boolean indicating whether a source site is to be ignored for staging to a destination site

Parameters:

source - the source site.

destination - the destination site.

Returns:

true if source is tp be ignored while staging to destination, else false.

globallyPreferred

protected boolean globallyPreferred(String site)

Returns a boolean indicating whether a site is a preferred replica source for all compute sites.

Parameters:

site - the site to test for.

Returns:

boolean.

globallyIgnored

protected boolean globallyIgnored(String site)

Returns a boolean indicating whether a site is to be ignored as a replica source for all compute sites.

Parameters:

site - the site to test for.

Returns:

boolean.

getProperty

protected String getProperty(String site,
                             String suffix)

Returns the name of the property, for a particular site X. The value of the property contains a comma separated list of site handles that are to be ignored|preferred while selecting replicas to stage to the site X.

Parameters:

site - the site X.

suffix - the property suffix to be applied.

Returns:

the name of the property.

populateSiteMaps

private void populateSiteMaps(String site)

Builds up the set of preferred and ignored sites for a site.

Parameters:

site - the site for which to identify the preferred and ignored sites.

getSitesSet

private Set getSitesSet(String value)

Returns a set of third party sites. An empty set is returned if value is null.

Parameters:

value - the comma separated list in the properties file.

Returns:

Set containing the names of the pools.