awp.trg.swctr-to4.ade-cave(lx)-01.00/02.00 rev. a this document includes data that shall not be...

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AWP.TRG.SWCTR-TO4.ADE-CAVE(Lx)-01.00/02.00 Rev. A

This document includes data that shall not be duplicated, used, or disclosed – in whole or in part – outside the Government for any purpose other than to the extent provided in contract DG133W-05-CQ-1067. However, the Government shall have the right to duplicate, use, or disclose the data to the extent provided in the contract. This restriction does not limit the Government’s right to use information contained in this data if it is obtained from another source without restriction. The data subject to this restriction are contained in all sheets.

Jan. 16, 2007

Advanced Weather Interactive Processing System II(AWIPS II)

AWIPS Development Environment (ADE)and the

Common AWIPS Visualization Environment(CAVE)

Module 3: Micro Engine and Scripts

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Jan. 16, 2007

Module 3: Micro Engine and Scripts

Module 3 Objectives• Learn Why the Micro Engine Exists and the Role It Plays

• Understand the Architectural Pattern of the Micro Engine

• Learn How to Write and Test Micro Engine Scripts

• Learn How to Extend the Micro Engine by Writing Micro Engine Tasks

• Learn About Future Evolution of The Micro Engine

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Jan. 16, 2007

uEngine Task Execution Pattern Breaks Up Execution Into Small Reusable Tasks

• uEngine Vision – Create an execution framework for generating custom products on

demand

– Customer systems can request products by script requests over a network

– The script performs small general units of work that get chained together to produce a customer product

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Jan. 16, 2007

uEngine Task Execution Pattern Breaks Up Execution Into Small Reusable Tasks

• uEngine Implementation – Runs out of an SOA services “ProductSrv” and “AutoBldSrv” that

are attached for I/O to ESB endpoints

– uEngine executes scripts in a XML language similar to “ANT”

– Utilizes the open source project “common-digester” for high-performance XML to object parsing

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Jan. 16, 2007

uEngine Used Out of Two SOA Services

IngestSrv PersistSrv IndexSrv ProductSrv

NotifySrv AutoBldSrvSubscribeSrv ColabrateSrv GridEditSrv

CAVEVisualization

Client

ADE 1.0 Services

Mbean Mbean Mbean Mbean

Mbean Mbean Mbean Mbean Mbean

JMX RemoteService Management

Client

ASCIIIngestSrvGridIngestSrvSBNSatIngestSrvRadarSrvLightingSrvProductSrv

FileSystemRDBMS via JDBC

Lucene – Reverse IdxSpatial R-Tree

uEngine ScriptsGrid Diagnostics

SubscriptionNotifyAlertNotify

Data RenderingNotify Response

CAVE ScriptingWx DrawingWx Warning

Data Interrogation

Delivered T03

Delivered T05

Enterprise Service Bus – HTTP, JMS, Virtual Memory, File Endpoints

Dissemination

AdapterSrv

Mbean

Exec AdapterHydro AdapterJini Adapter

Hydro Visualization

Delivered T04

uEngine Scripts

Services Independent of End Points

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Jan. 16, 2007

uEngine Design Concepts

• Idea originated out of ANT files– Think of uEngine tasks as being similar to ANT tasks inside <target>

– Most uEngine script tasks are “bodiless”

– Simplicity is guiding concept

– Tasks get executed from top to bottom in sequence, no controls

• Added Apache Commons Digester XML parser – Layered on SAX parsing

– Improves the performance of XML parsing

– Provides rule-based XML to Java Object mapping

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Jan. 16, 2007

uEngine Design Concepts

• Each Task defines its own parsing rules– Rules for a task can be changed with minimal impact on the micro

engine

– The abstract Task class provides convenience methods for many common rules

• Class bundle in uEngine identifies tasks– uEngine able to identify tasks included within its jar

– Enables new tasks to be added with a system build

– New tasks are “pluggable” – they do not require modifications to the existing uEngine

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Jan. 16, 2007

Commons Digester

<action name="ServiceGribImageDecode">

<termQuery>

<query name=“grid_type”

value=“22” />

</termQuery>

<degrib/>

<gribMap colorMap=“GribRGB” />

<colorImage colorMap=“GribRGB” />

<imageOut format=“png” />

<fileOut/>

<worldFileInfo/>

<makeServiceResponse />

</action>

uEngine Task Execution Pattern Common-Digester Based XML Rule Driven Parsing

<<ESB Service>>

ProductSrv

+receive()

{String output = (String) myLaunch.parseAndRun(msg);}

<<Java Class>>

Launcher+parseAndRun()

{action = DigesterSingleton.parse(reader);

action.executeTasks();}

<<Java Class>>

Action+executeTasks()

{Task task = i.next();

task.init(retObj);

retObj = task.execute();}

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Jan. 16, 2007

<action name="ServiceGribImageDecode"> <termQuery> <query name=“grid_type” value=“22” /> </termQuery>

<degrib/>

<gribMap colorMap=“GribRGB” />

<colorImage colorMap=“GribRGB” />

<imageOut format=“png” /> <fileOut/> <worldFileInfo/> <makeServiceResponse /></action>

uEngine Task Execution Pattern Connecting Units of Work Together - ChainDataType

termQuery query

degrib

gribMap colorMap

TaskXML child

elements

Input

ChainDataType

Output

ChainDataType

colorImage colorMap

imageOut format

fileOut

worldFileInfo

makeServiceResponse

<<abstract>>

Task+addRules(Digester)

+init(ChainDataType)

+ChainDataType execute()

Adding a new uEngine Task

1. Extend Task

2. Implement addRules()

3. Implement abstract methods

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Jan. 16, 2007

uEngine Task Execution Pattern Data Transformation Into Decision Aids - Scripting

mathScript

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Jan. 16, 2007

Writing and Testing uEngine Scripts

• General Rules– Remember the KISS principle – scripts generally create a single

product

– Script generally follow the Input-Process-Output (IPO) pattern

– Each script starts with a data query – you need to know the data that may available

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Jan. 16, 2007


• A Scripting Example

We want a script that will return the latest TAF for Omaha Eppley Airport. The ICAO for Omaha Eppley is KOMA. The data should be returned to the client as a raw TAF record.

• AnalysisIn this case, there is no processing to be performed. We simply retrieve the data and return it to the client. Two uEngine tasks are used:– termQuery, which is used to query the data store

– makeResponse, which returns the data to the client

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Jan. 16, 2007


• The Basic Tag Formats:– action – represents the script document. Encloses other tags.

<action name="…">

</action>

– termQuery – defines a query to the data store<termQuery>

<query name="…" value="…" />

</termQuery>

– makeResponse – prepares the data to return to the client<makeResponse returnMethod="…" />

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Jan. 16, 2007


• The Completed Script<action name="Get TAF">

<termQuery>

<query name="reportType" value="TAF" />

<query name="stationID" value="KOMA" />

</termQuery>

<makeResponse returnMethod="ascii" />

</action>

• This Returns the Raw Data to the Client

• Will Revisit This One on the Lab

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Jan. 16, 2007


• A Script Example

In this example, we again retrieve the latest TAF for KOMA, but in this case we will return the decoded report in XML format.

• Analysis

Two additional uEngine tasks are needed here:– decodeAscii, which is used to decode the record

– asciiXML, which converts the decoded report to XML format

• Note: To be useful, the client needs to “understand” the XML formatting.

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Jan. 16, 2007


• The Basic Tag Formats:– decodeAscii – runs the TAF decoder. We will revisit this one later

since it utilizes the plug-in pattern in performing the decoding.<decodeAscii />

– asciiXML – converts the decoded TAF to XML. This one also utilizes the plug-in pattern.<asciiXML />

• Note: Neither tag requires that the ascii report type be identified. This is part of the plug-in pattern.

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Jan. 16, 2007


• The Completed Script <action name="Get TAF">

<termQuery>

<query name="reportType" value="TAF" />

<query name="stationID" value="KOMA" />

</termQuery>

<decodeAscii />

<asciiXML />

<makeResponse returnMethod="ascii" />

</action>

• Will Revisit This One in the Lab

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Jan. 16, 2007


• Summary– Saw two example scripts that work with ASCII data

– More examples in the documentation included on the DVD

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Jan. 16, 2007

BREAK

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Jan. 16, 2007

Hands-On Micro Engine/Scripts

• Running the Development Version of EDEX

• Script Builder Web Page

• Running a Script

• Debugging a Script

• Script Editor Web Page

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Jan. 16, 2007

• Install EDEX on Development Computer

• To Start EDEX: Double Click the Start ActiveMQ, Start Mule, and Start Tomcat Icons on PC Desktop

• Linux Users: Start Edex From a Terminal

Running EDEX

3

2

1

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Jan. 16, 2007

Script Builder Web Page

• AWIPS ADE 0.1 Includes a Web Site That Can Be Used to Build/Debug uEngine Scripts– Does not have an empty editor

page; we will use the GRIB Retrieval Page

• Open the Browser.• Navigate to uEngineWeb Test

Page.• Click GRIB Retrieval Link.• Delete Contents of Blue Box.• Enter the Script to Test.

Steps:

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Jan. 16, 2007

Running a Script

Click the Get Image button

Enter the script into the blue box

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Jan. 16, 2007

Running a Script: Results

This is the TAF. The original formattingis retained, but notreflected on page.

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Jan. 16, 2007

Running a Script: Example 2

Click the Get Image button

Enter the script into the blue box

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Jan. 16, 2007

Running a Script: Results

This is the decoded TAF. XML formattingis hidden by the page rendering.

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Jan. 16, 2007

Debugging a Script

• uEngine Will Detect Common Scripting Errors– Invalid XML

– Invalid search parameters

– Missing tags

• This Error Caused by an Invalid (<degrib /> uEngine Script Tag

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Jan. 16, 2007

Script Editor Web Page

• AWIPS Test Driver Interface may be used as a script builder

• This interface used create scripts for this demo

• Expand the page to see the script

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Jan. 16, 2007

BREAK

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Jan. 16, 2007

Extending the uEngine by Adding New Tasks

• Steps Involved in Writing New uEngine Tasks

• Writing a “Hello World” Task

• Testing Your New Task

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Jan. 16, 2007

General Rules

• Remember the KISS principle – each task should perform a single job

• Most tasks extend Task. May also extend an intermediate class– Jython tasks extend JythonTask rather than Task, but JythonTask

extends Jython.

• Override the static addRules(Digester) method– At a minimum, call the static addBasicRules(…) method

• Implement the abstract init(ChainData), and execute() methods

• The abstract test(ChainData) method is currently deprecated and can be implemented by simply returning the input

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Jan. 16, 2007

The “Hello World” Task

• Problem Statement

We want to create a uEngine task so that a uEngine script can print a “Hello World” message.

• Analysis

In this case, we will interpret “print” as log a message. This allows for creation of a somewhat more useful task, one that will allow the script writer to log messages. For simplicity, the logging will be at “info” level.

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Jan. 16, 2007


• The XML Tag Syntax

<echo msg="…" />

The tag name will be echo. The text to be logged will be provided via the message attribute. The message will be static, i.e., it will be determined at the time the script is written.

• Log Output

Typical log output will be similar toINFO 2007-01-16 14:07:46, 964 [ProductSrv.2] tasks.Echo Message: Hello World!

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Jan. 16, 2007


• Basic Class Structure– Basic class generated by Eclipse

– Import statements added by Eclipse as needed

“msg” and setMsg() follow Java bean naming pattern.

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Jan. 16, 2007


• addRules(Digester) method:

• “Echo.class” specifies the class and is required since this is a static method

• Uses the rules method from Task and previously defined constants to simplify code

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Jan. 16, 2007


• The init(ChainData) and Test(ChainData) Methods

Init() simply saves its input for later, “dataChain” is provided by Task.

test() has nothing to do, so simply return the input.

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Jan. 16, 2007


• The Execute() Method– All the action takes place here

Use the logger to record the message

All Tasks return the dataChain.

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Jan. 16, 2007

The “Hello World” Task – Using Eclipse

Using the Eclipse Class Creation Wizard to create the basic class.

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Jan. 16, 2007

The “Hello World” Task – Using Eclipse

• At this point, you compile and deploy EDEX

• Once deployed, test the task in a uEngine script

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Jan. 16, 2007

The “Hello World” Task – Test Script

• Enter the test script as before, and click “Get Image”.

• Check the system log to see the message.

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Jan. 16, 2007

BREAK

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Jan. 16, 2007

Summary

• Future Evolution of the uEngine Design

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Jan. 16, 2007

Resources

• On the ADE 0.1 DVD:– micro_engine_task_readme.pdf– micro_engine_scripting_readme.pdf– generic message format.pdf– AWIPS_ADE_EDEX_Build_Procedure.pdf– JavaDoc documentation for plug-ins is available.

• On the Web:– Apache Commons Digester project:

• http://jakarta.apache.org/commons/digester /

– Apache Jakarta Commons project:• http://jakarta.apache.org/commons/ /

– Apache Ant project:• http://ant.apache.org/

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Jan. 16, 2007

BREAK

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