Basic VisiBroker Interview Preparation Guide

Download PDF

The default value of "vbroker.agent.localFile" property is "null".
Specifies which network interface to use on multi-home machines. This used to be the OSAGENT_LOCAL_FILE environment variable.

The default value of "vbroker.agent.keepAliveTimer" property is "120".
The duration in seconds during which the ORB will send keep-alive messages to the Smart Agent (applicable to both clients and servers). Valid values are integers between 1 and 120, inclusive.

The default value of "vbroker.agent.debug" Smart Agent Communication properties is "false".
When set to true, specifies that the system will display debugging information about communication of VisiBroker applications with the Smart Agent.

The default value of "vbroker.agent.clientPortRange" property is "0 (zero)".
Range of ports within interval [clientPort, clientPort+clientPortRange] for the ORB to communicate with the OSAgent. This property is effective only when clientPort is greater than 0 (zero). Valid values are between 0 and 65535.

The default value of "vbroker.agent.port" property is "14000".
Specifies the port number that defines a domain within your network. VisiBroker applications and the Smart Agent work together when they have the same port number. This is the same property as the OSAGENT_PORT environment variable.

The default value of "vborker.agent.clientPort" property is "0 (zero)".
Lower bound of the range of ports for the ORB to communicate with the OSAgent. Valid values are between 0 to 65535. Default value of 0 (zero) means that a random port will be selected.

The default value of "vbroker.agent.failOver" property is "true".
When set to true, allows a VisiBroker application to fail over to another Smart Agent.

The default value of "vbroker.agent.enableLocator" property is "true".
When set to false, does not allow VisiBroker applications to communicate with the Smart Agent.

The default value of "vbroker.agent.enableCache" property is "true".
When set to true, allows VisiBroker applications to cache IOR.

The default value of "vbroker.agent.addrFile" property is "null".
Specifies a file that stores the IP address or host name of a host running a Smart Agent.

The default value of "vbroker.agent.keepAliveTimer" property is "120 seconds".
Smart agent will wake up after this timeout and based on the vbroker.agent.keepAliveThreshold value, will compute whether to do client verification. The logic is if the last received heart beat value is less than current time - (keepAliveTimer + keepAliveThreshold), then do client verification. The value of this property should be greater than 1 second and less than 120 seconds. The number of times the client verification is tried can be controlled by vbroker.agent.maxRetries property.

The default value of "javax.rmi.CORBA.PortableRemoteObjectClass" property is "com.inprise.vbroker.rmi.CORBA.PortableRemoteObjectImpl".
Specifies that the RMI-IIOP server implementation objects may inherit from javax.rmi.PortableRemoteObject or simply implement an RMI-IIOP remote interface and then use the exportObject method to register themselves as a server object.

The default value of "vbroker.agent.addr" property is "null".
Specifies the IP address or host name of a host running a Smart Agent. The default value, null, instructs VisiBroker applications to use the value from the OSAGENT_ADDR environment variable. If this OSAGENT_ADDR variable is not set, then it is assumed that the Smart Agent is running on a local host.

The default value of "vbroker.agent.retryDelay" property is "0 (zero)".
The duration in seconds that the process will pause before trying to reconnect to the Smart Agent in the event of disconnection from the Smart Agent. If the value is -1, the process will exit upon disconnection from the Smart Agent. The default value of 0 (zero) means that reconnection will be made without any pause.

The default value of "vbroker.agent.maxRetries" property is "4 times".
The number of times the agent will do client verification on not receiving a heart beat from the client. Values can be 1 to 10.

The default value of "broker.agent.port" property is "14000".
Specifies the port number that defines a domain within your network. VisiBroker applications and the Smart Agent work together when they have the same port number. This is the same property as the OSAGENT_PORT environment variable.

The default value of "vbroker.agent.clientHandlerPort" property is "null".
Specifies the port that the Smart Agent uses to verify the existence of a client&mdash in this case, a VisiBroker application. When you use the default value, null, the Smart Agent connects using a random port number.

The default value of "vbroker.agent.keepAliveThreshold" property is "40 seconds".
Refer to documentation on vbroker.agent.keepAliveTimer. This value should be greater than 0.

The default value of "java.rmi.server.useCodebaseOnly" property is "false".
Specifies if a server is allowed to locate unknown classes, If set to true, does not allow the server to locate remote classes even if the client sends the location of the remote classes to the server.

The default value of "vbroker.agent.addrFile" property is "null".
Specifies a file that stores the IP address or host name of a host running a Smart Agent.

The default value of "java.rmi.server.codebase" property is "<not set>".
Specifies where a server can locate unknown classes. Acceptable value is semicolon (;)-separated URLs.

The default value of "javax.rmi.CORBA.UtilClass" property is "com.inprise.vbroker.rmi.CORBA.UtilImpl".
Specifies the name of the implementation of the Utility class that provides methods that can be used by stubs and ties to perform common operations.

The default value of "javax.rmi.CORBA.StubClass" property is "com.inprise.vbroker.rmi.CORBA.StubImpl".
Specifies the name of the implementation of the Stub base class from which all RMI-IIOP stubs must inherit.

The default value of "vbroker.rmi.supportRTSC" property is false.
This property enables or disables the exchange of SendingContextRuntime service contexts between clients and servers when the two are using different (evolved) versions of a class. If the client and server are on different versions of a JDK, the application should make sure that this property is set to true. This value should also be used for cases where VBJ is talking to a foreign ORB. This ensures that the codebase data is exchanged and marshaling/demarshaling of evolved classes can succeed without exceptions.

In addition to providing the features defined in the CORBA specification, VisiBroker offers enhancements that increase application performance and reliability.