Table of Contents
There is no "client" API for accessing WebMDS; WebMDS is a servlet that is accessed via web forms.
WebMDS uses a WebMDS plugin (a Java class that implements the
WebmdsXmlSource
interface) to acquire XML documents (which
can be used either as raw information sources or as XSL transformations).
WebMDS comes with two WebMDS plugins: FileXmlSource
, which
reads XML from a file (and is primarily used to acquire XSL transformations),
and NodeXmlSource
. NodeXmlSource
in turn calls
a node source plugin (a Java class that implements the
WebmdsNodeSource
interface) to acquire an XML DOM document.
acquires XML information using a WebMDS XML source,
a Java class that implements the WebmdsXmlSource
interface.
To summarize:
WebMDS is a servlet that uses plugins to acquire XML documents containing raw data and XSL transformations, and then applies the acquired XSL transformation on the acquired data.
- The plugins used by WebMDS implement the
org.globus.mds.webmds.WebmdsXmlSource
interface. WebMDS plugins include:
org.globus.mds.webmds.xmlSources.file.FileXmlSource
, which reads XML from a file, andorg.globus.mds.webmds.xmlSources.xmlDomNode.NodeXmlSource
, which uses its own plugin interface to acquire XML DOM documents.- The plugins used by
NodeXmlSource
implement theorg.globus.mds.webmds.xmlSources.xmlDomNode.WebmdsNodeSource
interface - Node source plugins include
org.globus.mds.webmds.xmlSources.resourceProperties.ResourcePropertyNodeSource
andorg.globus.mds.webmds.xmlSources.resourceProperties.ResourcePropertyQueryNodeSource
, which acquire resource property information.
- The plugins used by
- The plugins used by WebMDS implement the
- The raw XML data acquired by WebMDS is processed by XSL transformations; see the W3C XSLT Documentation for more information on creating XSL transforms.
- Core WebMDS documentation (includes the WebMDS servlet and the
WebmdsNodeSource
interface) - FileXMLSource documentation
- NodeXmlSource documentation (including the
WebmdsNodeSource
interface) - Resource property node source plugins.
WebMDS is not a Web service and does not have any associated WSDL. For information on the web form-based protocol used by WebMDS, see the documentation on the WebMDS Graphical User Interface.
There is no end-user command-line tool for WebMDS.
The command-line tool webmds-create-context-file
is used to
create Tomcat configuration files needed to deploy WebMDS.
webmds-create-context-file [-f] tomcat_context_file
The tomcat_context_file argument is the location of the Tomcat
configuration file defining the WebMDS context; in a default Tomcat
installation, the location of this file will be
$CATALINA_HOME/conf/Catalina/localhost
.
By default, webmds-create-context-file
will not overwrite
an existing context file; the -f
option is used to force
webmds-create-context-file
to overwrite an existing file.
Note: webmds-create-context-file
is found in
$GLOBUS_LOCATION/lib/webmds/bin
$GLOBUS_LOCATION/lib/webmds/bin/webmds-create-context-file -f \ $CATALINA_HOME/conf/Catalina/localhost
The WebMDS GUI is a web-based interface for browsing formatted XML data, such as the results of resource property queries on a grid service.
WebMDS can be accessed using any web browser. In a default WebMDS
installation, the URL http://hostname:port/webmds
corresponds to the top-level WebMDS web page. This page includes a link
to a WebMDS invocation that provides summary information (with links to
detailed information) about a locally-running MDS Index server. It also
contains a link to a page of sample web forms demonstrating other uses
of WebMDS.
The WebMDS servlet is located at http://your-tomcat-host:your-tomcat-port/webmds/webmds
.
It takes the following arguments:
Table 1. Form arguments used by WebMDS
info | The name of the XML source that will be used to collect the raw XML data.
XML sources are defined by files in
$GLOBUS_LOCATION/lib/webmds/conf . This argument must be
specified. |
xsl | The name of the XML source that will provide the XSL transform.
XML sources are defined by files in
$GLOBUS_LOCATION/lib/webmds/conf .
If this argument is not specified, the WebMDS servlet will display
raw, untransformed XML. |
xmlSource.info_name.param.source_specific_options | Any additional options recognized by the info_name XML source (info_name must be the value of the info argument for this request). Source-specific options are discussed in the next section. |
xmlSource.xsl_name.param.source_specific_options | Any additional options recognized by the xsl_name XML source (xsl_name must be the value of the xsl argument for this request). Source-specific options are discussed in the next section. |
WebMDS uses a web form interface to specify parameters such as where to find raw data and what XSLT transformations to apply to that data.
The web form interface is described in Section 3, “Graphical user interfaces”
WebMDS can be configured to get information from any of various sources and to filter it through any XSL transform. WebMDS uses configuration files to specify the location of (and to name) sources of information and xsl and web form arguments to select among these configured information sources and xsl transforms.
By default, WebMDS comes configured to report information about an index server using transaction-level security on the default port (8443) on the local system. If you are running the Globus Toolkit in this default configuration, then you can use WebMDS to query your local Index Service without any configuration changes.
If you wish to monitor a different index server,
you will need
to edit the file
$GLOBUS_LOCATION/lib/webmds/conf/indexinfo
to change
the URL in the line:
<value>https://127.0.0.1:8443/wsrf/services/DefaultIndexService</value>
to match the URL of your default index service. Changes to WebMDS configuration files take effect the next time that Tomcat is restarted.
For other configuration changes (e.g., monitoring different kinds of services), see the detailed configuration information below.
Each configuration file in $GLOBUS_LOCATION/lib/webmds/conf
defines a source of XML, which can be
used in an HTML form to specify sources of information and XSL transforms.
The distribution
contains some standard configuration files in this directory, including:
Table 2. Pre-configured information sources
indexinfo | all resource properties from an index server running with transaction-level security on port 8443 on the local host |
indexinfo_nosec | all resource properties from an index server running with no security on port 8080 on the local host |
openEndedQuery | all resource properties from a user-specified grid service |
openEndedRP | a user-specified resource property from a user-specified grid service |
servicegroupxsl | an xsl transform that presents summary information about a service group |
sgedetail | an xsl transform that presents detailed information about a service group entry |
Each configuration file defines a WebmdsConfig
object.
A WebmdsConfig
object consists of:
- A
description
: a textual description of the XML source being defined. - A
className
: the name of the Java class that will be used to acquire the XML data. - Zero or more
parameter
objects, each of which consists of thename
of some parameter recognized by the Java class specified byclassName
, and the stringvalue
of that parameter.
For example, this is
$GLOBUS_LOCATION/lib/webmds/conf/servicegroupxsl
, which defines
the servicegroupxsl
XML source:
<WebmdsConfig> <description> XSL file to show service group summary information </description> <className>org.globus.mds.webmds.xmlSources.file.FileXmlSource</className> <parameter> <name>file</name> <value>xslfiles/servicegrouptable.xsl</value> </parameter> </WebmdsConfig>
This file tells WebMDS to use the
org.globus.mds.webmds.xmlSources.file.FileXmlSource
Java class (a class which reads XML from a local file) to collect XML data
and to pass a file
parameter (which that Java class interprets
as the name of the file to open, relative to the WebMDS base directory).
Tomcat must be restarted (or one of the more advanced Tomcat administrative mechanisms must be used) for changes to these configuration files to take effect.
The class org.globus.mds.webmds.xmlSources.file.FileXmlSource
reads XML from a file, and recognizes a single parameter:
Table 3. Configuration parameters used with FileXMLSource
file | The name of the file to read. Relative path names are interpreted
relative to the WebMDS base directory
($GLOBUS_LOCATION/lib/webmds ).
|
This XML source class uses a WebmdsNodeSource object to fetch an XML document and return it in a form that is usable by WebMDS. It recognizes the following options:
The following classes implement the NodeXMLSource
interfaces
and can be used in conjunction with NodeXMLSource
This class performs a resource property query to get all the resource properties for some web service. It recognizes the following configuration parameters:
Table 5. Configuration parameters used with ResourcePropertyQueryNodeSource
endpoint | The endpoint name to be used in a resource property query. |
endpointKeyName
and endpointKeyValue | An optional key/value pair to use as reference properties for the
endpoint specified with the
endpoint
parameter. |
allowUserEndpoints | If true , values for
xmlSource.sourceName.param.endpoint ,
xmlSource.sourceName.param.endpointKeyName , and
xmlSource.sourceName.param.endpointKeyValue
specified in the request will override the configured endpoint value. |
endpointFile | The name of a file from which the endpoint information (in XML) will be read. This configuration parameter can never be overridden by request arguments. |
This class queries a web service for a single resource property. It recognizes the following parameters:
Table 6. Configuration parameters used with ResourcePropertyNodeSource
endpoint | The endpoint name to be used in a resource property query. |
endpointKeyName
and endpointKeyValue | An optional key/value pair to use as reference properties for the
endpoint specified with the
endpoint
parameter. |
allowUserEndpoints | If true , values for
xmlSource.sourceName.param.endpoint ,
xmlSource.sourceName.param.endpointKeyName , and
xmlSource.sourceName.param.endpointKeyValue
specified in the request will override the configured endpoint value. |
endpointFile | The name of a file from which the endpoint information (in XML) will be read. This configuration parameter can never be overridden by request arguments. |
rpNamespace | The namespace part of the QName of the resource property to be queried for. |
rpName | The local name part of the QName of the resource property to be queried for. |
allowUserResourceProperties
| If true , values of
xmlSource.sourceName.param.rpNamespace and
xmlSource.sourceName.param.rpNames
specified in the request will override the configured resource
property namespace and name. |