BES Aggregation - Revision history

PatrickWest at 12:54, 9 March 2009

2009-03-09T12:54:22Z

← Older revision		Revision as of 12:54, 9 March 2009
Line 148:		Line 148:

	For more information on the Module class and adding it to the BES configuration file, please refer to the [[Hyrax - Extending BES Module\|Extending the BES]] page.		For more information on the Module class and adding it to the BES configuration file, please refer to the [[Hyrax - Extending BES Module\|Extending the BES]] page.

			[[Category:Extending BES\|Aggregation]]

PatrickWest: /* Summary */

2009-03-09T11:07:37Z

Summary

← Older revision		Revision as of 11:07, 9 March 2009
Line 146:		Line 146:
	# Run the BES with this new module		# Run the BES with this new module
	# Implement your <code>aggregate</code> method		# Implement your <code>aggregate</code> method

			For more information on the Module class and adding it to the BES configuration file, please refer to the [[Hyrax - Extending BES Module\|Extending the BES]] page.

PatrickWest at 11:04, 9 March 2009

2009-03-09T11:04:21Z

← Older revision		Revision as of 11:04, 9 March 2009
Line 124:		Line 124:
	</pre>		</pre>

	The result of your aggregation will be a new DataDDS object that will take the place of the one you got out.		The result of your aggregation will be a new DataDDS object that will take the place of the one you got out. The end of your function might look something like this:

			<pre>
			....
			your code here
			...
			BESDataDDSResponse *my_bdata = new BESDataDDSResponse( my_data ) ;
			dhi.response_handler->set_response_object( my_bdata ) ;
			delete bdds ;
			}
			</pre>

			== Summary ==
			We recommend that your first step in writing your own aggregation server is to create the classes that you will need with an empty <code>aggregate</code> method, get it compiled and installed, load the module into the BES, and make sure that your aggregation method is being called. Once you have done this, then you can write your <code>aggregate</code> method.

			Here's what you need to do:
			# Create your class that inherits from BESAggregationServer using the code from above.
			# Register your AggBuilder function with the BESAggFactory in your Module class.
			# Build your new code, creating a shared object library (.so file) that can be loaded into the BES
			# Add your module to the BES configuration file
			# Run the BES with this new module
			# Implement your <code>aggregate</code> method

PatrickWest at 22:23, 8 March 2009

2009-03-08T22:23:19Z

@@ Line 108: / Line 108: @@
 <pre>
 </pre>
 The result of your aggregation will be a new DataDDS object that will take the place of the one you got out.

PatrickWest at 22:08, 8 March 2009

2009-03-08T22:08:50Z

← Older revision		Revision as of 22:08, 8 March 2009
Line 74:		Line 74:

	== Writing your <code>aggregate</code> method ==		== Writing your <code>aggregate</code> method ==
			The aggregate method is the only method that you need to implement. This is the method that gets called to aggregate the resulting DataDDS object. The DataDDS object is stored in the BESDataHandlerInterface instance passed to your method. Here is an example of getting the DataDDS out of the BESDataHandlerInterface.

			<pre>
			void
			NCESGAggregationServer::aggregate( BESDataHandlerInterface &dhi )
			{
			if( dhi.action == "das" )
			{
			string err = "DAS is not a valid request type in aggregated datasets" ;
			throw BESInternalError( err, __FILE__, __LINE__ ) ;
			}

			BESResponseObject *resp = dhi.response_handler->get_response_object() ;
			BESDataDDSResponse bdds = dynamic_cast<BESDataDDSResponse >(resp) ;
			if( !bdds )
			{
			string err = "response object is not a DataDDS" ;
			throw BESInternalError( err, __FILE__, __LINE__ ) ;
			}
			DataDDS *dds = bdds->get_dds() ;
			if( !dds )
			{
			string err = "dap response object is not a DataDDS" ;
			throw BESInternalError( err, __FILE__, __LINE__ ) ;
			}

			....
			your code here
			.....
			</pre>

			Once you have the DataDDS you have all of the data that has been read in and you can perform your aggregation. The DataDDS will be organized in the following manner. For each of the containers defined in the BES request (in our example, c1, c2, c3, and c4) there will be a structure containing the data for that container. So, in our example, you would have:

			<pre>
			</pre>

			The result of your aggregation will be a new DataDDS object that will take the place of the one you got out.

PatrickWest at 22:03, 8 March 2009

2009-03-08T22:03:10Z

@@ Line 2: / Line 2: @@
 == How does aggregation work in the BES? ==
-A request comes into the BES that references some containers, create a definition using those containers adding constraints and specifying an aggregation engine to use and an aggregation command, and then a get command to grab the containers, constrain them, and then aggregate. The command would look something like this:
+A request comes into the BES that references some containers, creates a definition using those containers adding constraints and specifying an aggregation engine to use and an aggregation command, and then a get command to grab the containers, constrain them, and then aggregate. The command would look something like this:
 <pre>
@@ Line 29: / Line 29: @@
 </request>
 </pre>

PatrickWest: /* How does aggregation work in the BES? */

2009-03-02T20:11:13Z

How does aggregation work in the BES?

← Older revision		Revision as of 20:11, 2 March 2009
Line 2:		Line 2:

	== How does aggregation work in the BES? ==		== How does aggregation work in the BES? ==
	A request comes into the BES ~~to reference~~ some containers, create a definition using those containers adding constraints and specifying an aggregation engine to use, and then a get command to grab the containers, constrain them, and then aggregate. The command would look something like this:		A request comes into the BES that references some containers, create a definition using those containers adding constraints and specifying an aggregation engine to use and an aggregation command, and then a get command to grab the containers, constrain them, and then aggregate. The command would look something like this:

	<pre>		<pre>

PatrickWest at 20:10, 2 March 2009

2009-03-02T20:10:33Z

← Older revision		Revision as of 20:10, 2 March 2009
Line 24:		Line 24:
	<constraint>u</constraint>		<constraint>u</constraint>
	</container>		</container>
			<aggregate handler="someHandler" cmd="someCommand" />
	</define>		</define>
	<get type="~~das~~" definition="d" />		<get type="dods" definition="d" />
	</request>		</request>
	</pre>		</pre>

PatrickWest: New page: By default there are no aggregation engines installed with the BES. But there is a mechanism to register your own aggregation engine. This page will discuss how to go about doing that. ==...

2009-03-02T20:08:23Z

New page: By default there are no aggregation engines installed with the BES. But there is a mechanism to register your own aggregation engine. This page will discuss how to go about doing that. ==...

New page

By default there are no aggregation engines installed with the BES. But there is a mechanism to register your own aggregation engine. This page will discuss how to go about doing that.

== How does aggregation work in the BES? ==
A request comes into the BES to reference some containers, create a definition using those containers adding constraints and specifying an aggregation engine to use, and then a get command to grab the containers, constrain them, and then aggregate. The command would look something like this:

<pre>
<?xml version="1.0" encoding="UTF-8"?>
<request reqID="some_unique_value" >
<setContainer name="c1" space="catalog">/data/nc/fnoc1.nc</setContainer>
<setContainer name="c2" space="catalog">/data/nc/fnoc2.nc</setContainer>
<setContainer name="c3" space="catalog">/data/nc/fnoc3.nc</setContainer>
<setContainer name="c4" space="catalog">/data/nc/fnoc4.nc</setContainer>
<define name="d">
<container name="c1">
<constraint>u</constraint>
</container>
<container name="c2">
<constraint>u</constraint>
</container>
<container name="c3">
<constraint>u</constraint>
</container>
<container name="c4">
<constraint>u</constraint>
</container>
</define>
<get type="das" definition="d" />
</request>
</pre>