A customer has a critical, performance-sensitive web application that connects to a multimode
Oracle RAC database. Which feature of WebLogic can provide signification benefit?
A.
The Web Session Affinity feature of Active GridLink for RAC.
B.
WebLogic Clustering
C.
The Transaction Affinity feature of Active GridLink for RAC
D.
Coherence*Web Session Replication
Explanation:
Active GridLink for Oracle RAC
In Oracle WebLogic Server 10.3.4, a single data source implementation has been introduced to
support an Oracle RAC cluster. It responds to FAN events to provide Fast Connection Failover
(FCF), Runtime Connection Load-Balancing (RCLB), and RAC instance graceful shutdown. XA
affinity is supported at the global transaction Id level. The new feature is called WebLogic Active
GridLink for RAC; which is implemented as the GridLink data source within WebLogic Server.
Note:
* The WebLogic Server JDBC subsystem has supported Oracle RAC since WLS version 9.0,
originally developed for Oracle9i RAC. This support is based on a particular type of data source
configuration, called a multi data source. A multi data source is a data source abstraction over one
or more individual data sources. It serves JDBC connections from each of the member data
sources according to a specified policy. A RAC multi data source configuration requires that each
member data source obtain connections to a particular RAC instance.
Reference: How-To: Use Oracle WebLogic Server with a JDBC GridLink Data Source
A
Session Affinity Policy
Web applications have better performance when repeated operations against the same set of records are processed by the same RAC instance. Business applications such as online shopping and online banking are typical examples of this pattern.
http://docs.oracle.com/cd/E28280_01/web.1111/e13737/gridlink_datasources.htm#JDBCA525
not D
This is for transaction 2phase commit XA.
The Answer is A
GridLink Affinity:
WebLogic Server GridLink affinity policies are designed to improve application performance by maximizing RAC cluster utilization. See:
Session Affinity Policy
XA Affinity Policy
Session Affinity Policy
Web applications have better performance when repeated operations against the same set of records are processed by the same RAC instance. Business applications such as online shopping and online banking are typical examples of this pattern.
An AGL data source uses the Session Affinity policy to ensure all the data base operations for a web session, including transactions, are directed to the same Oracle RAC instance of a RAC cluster.
Note:
The context is stored in the HTTP session. It is up to the application how windows (within a browser or across browsers) are mapped to HTTP sessions.
If an AGL data source with a session affinity policy is accessed outside the context of a web session, the affinity policy changes to the XA affinity policy. See XA Affinity Policy.
https://docs.oracle.com/middleware/1212/wls/JDBCA/gridlink_datasources.htm#JDBCA525
Ans – C
The question never says “same set of records” to be processed by the same RAC instance. It only mentions about performance-sensitive web application. So IMO, C is the correct answer.
By enabling Transaction Affinity, the connection will be stored in the global transaction, hence any new invocation to the same RAC instance can use the same connection instead of obtaining a new connection to the RAC instance which will improve performance.
the answer is A.
from OLN presentation Proficiency Training Will Lyons Director of Product Management Oracle WebLogic Server:
Web Session Affinity
New Affinity type in WebLogic Server 10.3.6
Supported in WebLogic Server 12.1.1
Connection requests use Affinity “hint”
Performance for Web Apps up to 4X
C