WebLogic is a J2EE server and as such provides support for J2EE API’s including.
JDBC
JTA
EJB
RMI over IIOP
Servlets
JSP
JNDI
JMS
WebLogic defines a number of concepts so before we get rolling we should investigate what WebLogic server physically is.
When you installed WLS you choose a directory to put it in, we will call this the <install directory>
The Files and the files and folders created by the install includes tools to start, stop, and administrate your WLS installation.
WLS version 6 runs on and ships with Java version 1.3, the install includes JDK 1.3.0 in <install directory>\jdk130
Thankfully we won’t cover every detail about WLS and how it is configure and how to set up every option.
We will focus on getting enough information about WLS so you can successfully setup a WLS server.
We will get started on monitoring your WLS configuration, so you can trouble shoot.
We will look at some configuration options and get more comfortable configuring WLS.
When you install WebLogic Server it comes with all the tools you need to visually configure and monitor your J2EE server. Start me up
There are several ways to startup a WLS server.
In windows you can use the Start menu. Start > Programs > BEA … > BEA WebLogic Server > Start Default Server
You can start the Server from the command line using a predefined script. Navigate to your domain under the <install directory> and run the script called “startWebLogic”.
You can run WLS as a Service in Windows. To configure services open the control panel and select “services”. WebLogic Server should appear in the list.
You can also fire up WLS in a more direct fashion using the command line without scripts. Because of the difficulty with the command line it is common to write your own startup scripts for a server.
WebLogic is a Java class, and it is run in a Java Virtual machine. To start your server type in “java weblogic.Server”.
To successfully start the server the options to the java command must include the following.
-classpath
-Dweblogic.Name=
-Dweblogic.managementusername=
-Dweblogic.management.username=
There are optional parameters as well.
-Dweblogic.RootDirectory=
-Dweblogic.RootDirectory=
-Dweblogic.Domain=
WebLogic View
From a WebLogic perspective, the WebLogic Server sits as a middleman between the clients and services that are provided.
There are several different types of clients that can call into WebLogic.
Web Browsers
Java Applets and applications
Connected PDA’s and Cell Phones
CORBA clients
COM objects
In addition to a database (RDBMS) there are several server side or backend services that a typical application server will have to access.
Database
Legacy Systems
COM components
To provide communications between the variety of clients and server applications WLS uses several protocols.
HTTP is used for web communication.
WLS can serve as a Web Server and be used to communicate to browsers such as Internet Explorer or Netscape Navigator.
HTTP is used for communicating to mobile devices with WAP filters.
HTTPS is a secure version of HTTP used to transfer more sensitive data. HTTPS uses a Secure Socket Layer (SSL).
T3 is another protocol used to communicate to WebLogic.
T3 was defined by BEA and is used in BEA products like Tuxedo.
T3 has a secure version of the protocol called T3S, which uses SSL.
T3 can be used by applets and applications to communicate to a server without using HTTP or going through a web server.
Thread Pools
When a request is sent into WLS it is put in a queue with all other requests.
A “pool” of threads handles the tasks in the execution queue.
Each task placed in the queue must wait until a thread is available to process it.
The number of threads created in the thread pool is a big part of the customization of your WLS installation.
By creating many threads the requests will be handled quicker, to a point.
Defining too many threads in the Thread Pool will cause performance degradation as the administration and overhead of keeping track of all the threads becomes too much.
The default number of threads in the pool is 15; you can configure it to be between 10 and 40. (We will see how to configure soon.)
A quick visualization of the thread pool and task queue follows.