PM12501: PERFORMANCE ISSUE WHEN USING ID TYPE ELEMENTS WITH SDOS

APAR status

• Closed as program error.

Error description

• A potential performance problem exists in this scenario:
  
  A large amount of data in a Service Data Objects (SDO) uses
  the following Property type for the configAttribute element:
  
  <xsd:complexType name="Property">
  <xsd:sequence>
  <xsd:element name="name" type="xsd:string" />
  <xsd:element name="value" type="xsd:string" />
  </xsd:sequence>
  </xsd:complexType>
  <xsd:complexType name="someConfig">
  <xsd:sequence>
  <xsd:element name="configAttribute"
  type="tns:Property"
  minOccurs="0" maxOccurs="unbounded" />
  </xsd:sequence>
  </xsd:complexType>
  
  
  The sdo.xml would look like this:
  
  <someConfig>
  <configAttribute>
  <name>some_type</name>
  <value>
  </value>
  </configAttribute>
  <configAttribute>
  <name>some_type_2</name>
  <value>no</value>
  </configAttribute>
  <configAttribute>
  <name>something_enabled</name>
  <value>yes</value>
  </configAttribute>
  <configAttribute>
  <name>some_name</name>
  <value>a_value</value>
  </configAttribute>
  </someConfig>
  
  The SDO contains over 500 of these configAttribute elements.
  
  
  At runtime, it could take about 3-5 ms to get values using an
  XPath expression:
  
  sdo.getString("someConfig/configAttribute[name='some_name
  ']/value")
  
  
  In order to take advantage of the fix in this APAR, it will be
  necessary to change the type of the 'name' element in the
  complexType to be xsd:ID instead of xsd:string:
  
  <xsd:complexType name="Property">
  <xsd:sequence>
  <xsd:element name="name" type="xsd:ID" />
  <xsd:element name="value" type="xsd:string" />
  </xsd:sequence>
  </xsd:complexType>
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  Users of IBM WebSphere Application Server   *
  *                  v7 Feature Pack for Service Component       *
  *                  Architecture (SCA) Refresh Pack v1.0.1 and  *
  *                  WebSphere Process Server v7.0               *
  ****************************************************************
  * PROBLEM DESCRIPTION: Performance issue when using SDOPath    *
  *                      expressions with predicates             *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  An SDOPath with a predicate such as "a/b[c='value']" iterates
  through all "b" properties looking for a "c" property with
  the value "value". This can be slow if there are many "b"
  properties and the desired one appears near the end.
  

Problem conclusion

• An optimization that takes advantage of xs:ID processing is now
  in place. In the above example, if the "c" property is of type
  xs:ID, the "b" property may be quickly located if the tree of
  DataObjects has already been fully created.
  
  APAR PM12501 is currently targeted for inclusion in Service
  Level (Fix Pack) 1.0.1.7 of WebSphere Application Server v7
  Feature Pack for Service Component Architecture (SCA) Refresh
  Pack. Please refer to the Recommended Updates page for
  delivery information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  WAS SCA FEATURE

• Fixed component ID

  5724J0854

Applicable component levels

• R700 PSY

     UP