Workload Management and Processing Control for Enterprise Java Beans in WebSphere
 Technote (troubleshooting)
 
Problem(Abstract)
Can EJB processing be fine tuned or regulated based upon customer defined or type specification?
 
Resolving the problem
Not in current releases of WebSphere®.

There are various settings to manage containers, connection pools, servers etc...but none specifically for EJB component control regarding EJB instance distributions (work load management piece for EJB xyz) or types Message Drive Bean (MDB) that customer wishes to control processing for.

EJB work load management is enabled automatically when a cluster is created within a cell. Simply put its managed through initial context, ORB, JNDI context, home object, LSD, IOR and WLM plugin-cfg.

WLM uses round robin routing wieghting distribution algorithum, where you can set ejb server weights, to distribute application server workload via
Servers -> Clusters -> <cluster_name> -> Cluster members

WLM does not control how many instances of an EJB are created. If an
object is WLM-enabled, then WLM will route requests (e.g. weight round
robin). There is no way to keep this from occuring in an ND
environment, except in cases where there is affinity to one particular
instance of a bean. The workload management service uses the concept of transaction affinity to direct client requests regarding stateful session entity beans, After a server is selected, client requests are directed towards it for the duration of the transaction, until its destroyed by the client or serverside request time-out expiration.

Emphasis is placed on ejb processing or rather load balancing from an application server perspective, but not on separation of processing regarding specific type of customer defined ejbs.

Prefer Local further adds request for processing of EJB on node where client resides.
Can ejb processing be configured or possibly customized from the EJB
programming layer or centralized serverside component tuning in
WebSphere??

It appears at least from a supplied component level, that type of fine granularity processing control does not presently exist in WebSphere.

The extent of provided end user EJB processing or workload control lies solely with round robin weight distribution algorithm for cluster members and with Prefer Local Enabled.

Related links:

SG246198 IBM WebSphere V5.1 Performance, Scalability, and High Availability WebSphere Handbook Series: Chapter 6
http://www.redbooks.ibm.com/redbooks/SG246198/wwhelp/wwhimpl/java/html/wwhelp.htm

http://publib.boulder.ibm.com/infocenter/ws40help/index.jsp?topic=/com.ibm.websphere.v4.doc/wasa_content/07010602.html

http://manuals.sybase.com/onlinebooks/group-as/asg1250e/ejbserv/@Generic__BookTextView/1985;pt=1979


Access intent policies, session facades and isolation level were also reviewed, but none applied.
 
 
Cross Reference information
Segment Product Component Platform Version Edition
Application Servers Runtimes for Java Technology Java SDK
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Workload Management (WLM)
Operating system(s): Windows
Software version: 6.1
Software edition:
Reference #: 1196000
IBM Group: Software Group
Modified date: Mar 28, 2006