wdk applications query modification for...

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WDK Applications Query Modification for Performance

Performance Engineering Group

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Agenda

Background– Is it the Query?

Conceptual solution– What can we do?

Steps to follow– How can we fix it?

The performance problem can occur right off, or after time with higher concurrency or larger repository.The fact that the instructions are inside a compiled class, make it impossible to fix without coding.Luckily, the coding is not that difficult so WDK novices can still fit it.

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The Challenges with Queries in WDK

WDK is a framework of pre-built componentsGeneric queries are generated to perform on all databases

– Oracle, SQL Server, Sybase and DB2

Sometimes out-of-the-box queries may not perform as well– Data model or data skew– Database behavior

How do we change pre-built component logic?– Query is in a compiled java class – Appears to be no way to modify it….

WDK is a framework with reusable, pre-built components and controls that perform common Documentum content management functions. Reality – The generic code is written to work for most of the situations, most of the time.Some database are more prone to “issues”. Data models and Data skew can also complicate the matter.

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Something in Webtop performs poorly

2. Request converted to DQL queryWebtop WDK

Query Constructor

DFC

DQL

Q ue r

y

Content Server

Database

1. URL sent from browser

SQL

Que

ry

3. DQL sent to Content Server

4. DQL converted to SQL and sent to Database

DQL

Resu

lt sSQ

LRe

s ult s 5. Results pulled back

(as app server calls dmcl ‘next’ method)

6. Results formatted as HTML page, sent to browser

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Our Focus: When Webtop generates ‘sub-optimal DQL’

We’ll focus on the query constructor;Not the browser page building or the content server processing

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Different ways to Change or Optimize Queries

Append DQL hintsModifying the WHERE clause

– remove of case-insensitivity functions

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Conceptual Solution

We want to modify the generated query– Only for a particular application – Only modify the scenario that is sub-optimal

We don’t want to recode– decode, modify and recode the class

We want upgrades to work– and patches to still apply

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What we’ll need?

Webtop Installation on Test System!WDK Installed over Webtop to be customizedInstall IDE environment to compile java classes

– Netbeans.org– Eclipse.org

Some help in WDK Documentation– WDK and Client Application Development Guide– WDK and Applications Tutorial

integrated development environmentSomething to compile our java into a classWDK install will detect the webtop install and build a customization area

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Methodology

6. Modify query string

1. Define the Problem

2. Find ‘the’ Component

3. Find managing Method

4. Create Extension for Component

5. Call super class in extension

Reproduce poorly performing Webtop functionGet dmcl trace of the function queryGet session trace finding the WDK Component that handles that query stringCreate custom code that calls Super class then modifies the queryShow results of the customization in dmcl traceReproduce Webtop function and its performance

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Methodology

1. Define the problem

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Example: Cabinet Displayhttp://localhost:8088/webtop/component/main?Reload=10&__......

SELECT SELECT upper(object_nameupper(object_name), ), r_object_idr_object_id, , ……FROM FROM dm_cabinetdm_cabinetWHERE (WHERE (is_privateis_private = 0 or = 0 or owner_nameowner_name = = USER) andUSER) anda_hiddena_hidden = false = false ORDER BY 1ORDER BY 1


We know there is a query behind a poorly performing function

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DMCL Trace of the Function

Trace.log File# [ 27 ] Tue Sep 28 14:59:22 2004

927999 ( 1.400 sec) ( 1998 rpc) API> query_cmd, s2,T,F,,,,,select upper(object_name),r_object_id,r_object_type,object_name,owner_name from dm_folderwhere folder('/Folders') and a_is_hidden=false order by 1

Application Server


First start Webtop, then open a new window and start the trace. Then we take the focus back to the webtop window.This is the time to return the query to the app server. It doesn’t include the time to build the page that issued the query.

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Methodology



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Session Trace of the Component

App Server Log

/80956219 [http8080-Processor3] DEBUG com.documentum.web.common.Trace - Component: Form ImplClass = com.documentum.webtop.webcomponent.streamline.streamlineView

Application Server

2. Find Component

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Session Component Trace Output

80956219 [http8080-Processor3] DEBUG com.documentum.web.common.Trace - Component: Resolved Start Page = /webtop/webtop/streamline/streamlineview.jsp

80956219 [http8080-Processor3] DEBUG com.documentum.web.common.Trace-Component: Form Impl Class = com.documentum.webtop.webcomponent.streamline.StreamlineView

2. Find Component

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Application Layers of WDK

wdk layer:– <AppServerRoot>\webapps\<virtualroot>\wdk\

webcomponent layer:– <AppServerRootr>\webapps\<virtualroot>\webcomponent\

webtop layer:– <AppServerRoot>\webapps\<virtualroot>\webtop\

2. Find Component

A WDK-based application has a root directory that contains WEB-INF directory and application layer directories such as ‘wdk’ and ‘/webcomponent’. Documentum WDK client applications add the application layer ‘/webtop’, ‘/wp’, ‘/dam’, ‘/da’. The ‘/custom’ application layer is provided for your customizations. Your custom application layer should extend the applications definition of the top-level application and then add or override functionality.

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com.documentum.webtop.webcomponent.streamline.StreamlineView

2. Find Component

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Class Component Extensions

MyComponent

Component

Method-1()

Method-2()

Method-1()

We’ll leverage Java functionality to call another method

This method overrides the one in the super class, however it can call the super class method

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Methodology




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Managing Methods in the Class

StreamlineView extends DrillDown {

You will need WDK expertise hereYou will need WDK expertise here……....

() { ….. }

ItsGreektoMe() { ….. }

}

3. Find Managing Method

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Managing Methods in the Class


Are any of the methods involved with creating the query?It’s not in the StreamlineView class directly

onInit() { ….. }

updateControlsFromPath() { ….. }

}


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Does this class extend any other class?


It might not be obvious..

If its not, then its likely the class that this extends, has the logic

onInit() { ….. }


}


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StreamlineView extends Drilldown

StreamlineView

DrillDown

Where can I find DrillDown.java?


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Look for path of DrillDown…


Import statement is a fully qualified path

onInit() { ….. }


}

Import com.documentum……drilldown.DrillDown;


Sometime fully-qualified class name, but not always

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com.documentum.webcomponent.navigation.drilldown.DrillDown


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Check the Class that was Extended

DrillDown {

onInit() { ….. }onRefreshData() { ….. }

onClickBreadcrumb() { ….. }

updateControlsFromPath() { ….. }readConfig() { ….. }

}


Now we check out the methods in this class, that were referenced in the StreamlineView class

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Are any Methods Creating the Query?

DrillDown {

In this example, updateControlsFromPath method was constructing the query and putting it into a datagrid

Now we know we need to ‘override’ updateControlsFromPath

onInit() { ….. }

updateControlsFromPath() { ….. }readConfig() { ….. }

}


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Methodology





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Create our Extension of StreamlineView

StreamlineView

DrillDown

MyStreamlineView extends StreamlineView which extends DrillDownWe only need to add a method called: updateControlsFromPath()

MyStreamlineView

4. Extend Component

We want to: Copy StreamlineView.java to custom areaRemoved all unneeded referencesExtended the updateControlsFromPath() method

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4. Extend Component

com.documentum.custom.mystreamlineview.MyStreamlineView

Create a custom java class in WDK

Create custom area as described in the WDK Application Development GuidePut MyStreanlineView.java in the custom area

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Methodology






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How to get the original logic?

In MyStreamlineView.java– Don’t want to have to duplicate all of the original logic– Need to ensure all previous logic is called ‘as is’

Achieve this by calling super class:

super.overridden_method_name(variable);

Example:

super.updateControlsFromPath( strpath )

5. Call Super Class

In MyStreamlineView.java

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Create custom Class to extend StreamlineView

StreamlineView

DrillDown

MyStreamlineView

updateControlsFromPath( strpath ) { …. super.updateControlsFromPath( strpath ); ….. /* Own custom logic */ …

}

updateControlsFromPath( strpath ) { …. super.updateControlsFromPath( strpath ); ….. /* custom logic */ …

}

updateControlsFromPath( strpath ) { …. }

5. Call Super Class

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Methodology

6. Modify query string






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Modify Code

Get the stringIn most cases just “append” query hint to stringPut new query into datagrid (if required)Compile your classReboot application server

select object_namefrom dm_sysobject

6. Modify Query String

enable (RETURN_TOP 100)

bufDql.appendbufDql.append

(" (" enable(RETURN_TOPenable(RETURN_TOP 100)");100)");

import com.documentum.webcomponent.library.messages.MessageService;public class MyStreamlineView extends com.documentum.webtop.webcomponent.streamline.StreamlineView

{bufDql.append(QUERY_DOC_6);

}// DQL Hint AddedbufDql.append(" enable(RETURN_TOP 100)");// DQL Hint EndMessageService.addMessage( this, "document query: " + bufDql.toString()); Datagrid dgrid = (Datagrid)getControl(CONTROL_DOCGRID, Datagrid.class);DataProvider dproviderFile = dgrid.getDataProvider();dproviderFile.setQuery(bufDql.toString());

}

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Other uses…

Advanced Search (will be revamped in 5.3)– Strip Lower()

Query using an Oracle hintChange a query to use default_result_set instead of keyset cursors to avoid blocking issues.

6. Modify Query String

Anything you can do in DQL and API

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Questions?

Look for FAQs published at http://developer.documentum.com

– Sometimes FAQs in Performance Section– Sometimes FAQs under individual product areas

[email protected]

wdk applications query modification for...

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