ORB service settings in administrative console

 

To configure the Java ORB service...

administrative console | Servers | Application Servers | serverName | ORB Service

Tweaking ORB settings can improve application performance in the case of applications containing enterprise beans. You can make changes to these settings for the default server or any appserver configured in the administrative domain.

 

Configuration tab

Request timeout Specifies the number of seconds to wait before timing out on a request message.

For use in command-line scripting, the full name of this system property is com.ibm.CORBA.RequestTimeout.

Data type int
Units Seconds
Default 180
Range 0 to 300

Request retries count Specifies the number of times that the ORB attempts to send a request if a server fails. Retrying sometimes enables recovery from transient network failures.

For use in command-line scripting, the full name of this system property is com.ibm.CORBA.requestRetriesCount.

Data type int
Default 1
Range 1 to 10

Request retries delay   Specifies the number of milliseconds between request retries.

For use in command-line scripting, the full name of this system property is com.ibm.CORBA.requestRetriesDelay.

Data type int
Units Milliseconds
Default 0
Range 0 to 60

Connection cache maximum   Specifies the largest number of connections allowed to occupy the connection cache for the service. If there are many simultaneous clients connecting to the server-side ORB, this parameter can be increased to support the heavy load up to 1000 clients.

For use in command-line scripting, the full name of this system property is com.ibm.CORBA.MaxOpenConnections.

Data type Integer
Units Connections
Default 240

Connection cache minimum   Specifies the smallest number of connections allowed to occupy the connection cache for the service.

Data type Integer
Units Connections
Default 100

ORB tracing   Enables the tracing of ORB GIOP messages.

This setting affects two system properties: com.ibm.CORBA.Debug and com.ibm.CORBA.CommTrace. If you set these properties through command-line scripting, set both to true in order to enable the tracing of GIOP messages.

Data type Boolean
Default Not enabled (false)

Locate request timeout   Specifies the number of seconds to wait before timing out on a LocateRequest message.

For use in command-line scripting, the full name of this system property is com.ibm.CORBA.LocateRequestTimeout.

Data type int
Units Seconds
Default 180
Range 0 to 300

Force tunneling   Controls how the client ORB attempts to use HTTP tunneling.

For direct access, the full name of this property is com.ibm.CORBA.ForceTunnel.

Data type String
Default NEVER
Range Valid values are ALWAYS, NEVER, or WHENREQUIRED.

Additional information about valid values follows...

ALWAYS Use HTTP tunneling immediately, without trying TCP connections first.

NEVER Disable HTTP tunneling. If a TCP connection fails, a CORBA system exception (COMM_FAILURE) is thrown.

WHENREQUIRED Use HTTP tunneling if TCP connections fail.

Tunnel agent URL Specifies the URL of the servlet used to support HTTP tunneling.

This must be a properly formed URL, such as http://w3.mycorp.com:81/servlet/com.ibm.CORBA.services.IIOPTunnelServlet or, for applets, http://applethost:port/servlet/com.ibm.CORBA.services.IIOPTunnelServlet. This field is required if HTTP tunneling is set.

For use in command-line scripting, the full name of this system property is com.ibm.CORBA.TunnelAgentURL.

Pass by reference Specifies how the ORB passes parameters. If enabled, the ORB passes parameters by reference instead of by value, which avoids making an object copy. If you do not enable pass by reference, the parameters are copied to the stack before every remote method call is made, which can be expensive.

If the EJB client and the EJB server are installed in the same WebSphere Application Server instance, and the client and server use remote interfaces, enabling Pass by reference can improve performance up to 50%. Pass by reference helps performance only where non-primitive object types are passed as parameters. Therefore, int and floats are always copied, regardless of the call model.

Enable this property with caution, because unexpected behavior can occur. If an object reference is modified by the remote method, the caller might change.

For use in command line scripting, the full name of this system property is com.ibm.CORBA.iiop.noLocalCopies.

Data type Boolean
Default Not enabled (false)

The use of this option for enterprise beans with remote interfaces violates the EJB Specification, Version 2.0 (see section 5.4). Object references passed to EJB methods or to EJB home methods are not copied and can be subject to corruption.

Consider the following example 

Iterator iterator = collection.iterator();
MyPrimaryKey pk = new MyPrimaryKey();
while (iterator.hasNext()) {
   pk.id = (String) iterator.next();
   MyEJB EJB = EJBHome.findByPrimaryKey(pk);
}

In this example, a reference to the same MyPrimaryKey object passes into WAS with a different ID value each time. Running this code with Pass by reference enabled causes a problem within the appserver because multiple enterprise beans are referencing the same MyPrimaryKey object. To avoid this problem, set the system property com.ibm.websphere.ejbcontainer.allowPrimaryKeyMutation to true when Pass by reference is enabled. Setting Pass by reference to true causes the EJB container to make a local copy of the PrimaryKey object. As a result, however, a small portion of the performance advantage of setting Pass by reference is lost.

As a general rule, any application code that passes an object reference as a parameter to an enterprise bean method or EJB home method must be scrutinized to determine if passing that object reference results in loss of data integrity or other problems.

 

See Also

Managing Object Request Brokers
Administrative console buttons
Thread pool settings
Object Request Broker communications trace
Object Request Brokers: Resources for learning