Category: Configuring Oracle Weblogic

Oracle WLS JVM settings

Setting the proper JVM Heap size is essential for applications requiring large memory areas. Generally speaking, the JVM settings of the Weblogic Administration server is not a vital task as applications should not be allowed to run on the administrative unit; however, this is an acceptable option if you are using it in the development stage. On the other hand, Weblogic Managed Servers should be tuned with the right amount of memory so that your applications won’t raise “Out of memory” errors but, at the same time, no excessive amount of memory is loaded.

Administration server JVM settings

JVM size of Admin server can be increased by changing –Xmx and -Xms values in setDomainEnv.sh (setDomainEnv.cmd for Windows) that is located in MW_HOME/user_projects/domains/<Domain>/bin

Within the setDomainEnv script, before “SET JAVA_OPTIONS=….”, you can specify the memory settings in the USER_MEM_ARGS variable. The format varies depending on your operating system and the kind of JVM that you are running. The following table summarizes the lines of code you should add, by providing a sample JVM configuration:

Weblogic Managed server JVM settings

JVM size of Managed Servers can be configured from the Weblogic console. This can be achieved by navigating into the Environment > Servers tab. From there, select your server and click on the upper Server Start tab. The following screen will be displayed:

Within this screen, enter the JVM arguments in the text area named “Arguments”. The new arguments will be triggered on the next server restart.

In order to start a Weblogic Server using the Node Manager perform the following tasks:

1.       Make sure that the server is associated with a Machine. This can be checked through the Configuration | General option of the Server window.

2.       Make sure that also the Node Manager is started on the Machine that hosts the server.

3.       Move to the Server | Control window. In the lower table, you can check the servers you want to start and simply click on the Start button.

Troubleshooting Node Manager

A common source of issues is related to the certificate hostname verification. As a matter of fact, when trying to connect to the NodeManager a check verification is performed based on the certificate which is configured as IdentityKeystore.

Certificates are located into the MW_HOME\Weblogic\wlserver\server\lib\ folder and the default (demo) certificate is named DemoIdentity.jks.

It can happen that the certificate has been bound to an hostname which has changed (think about a change in your network configuration). This generally produces a message like this on the console:

Certificate chain received from localhost – 127.0.0.1 failed host name verification check. Certificate contained rhp360-c4-13 but check expected localhost

Then, the first check to be done is that the Machine Listen address corresponds to the hostname of the certificate. If you still cannot solve the issue, don’t panic! you can still re-generate your certificate in a minute by executing the CertGen utility and the corresponding ImportPrivateKey as follows:

C:\wls1211_dev\wlserver\server\bin>setWLSEnv.cmd  java utils.CertGen -cn localhost -keyfilepass DemoIdentityPassPhrase -certfile testcert -keyfile testkey

java utils.ImportPrivateKey DemoIdentity.jks DemoIdentityKeyStorePassPhrase demoidentity DemoIdentityPassPhrase testcert.pem testkey.pem

Now copy this certificate into MW_HOME\wlserver\server\lib (before backing up a copy of the default DemoIdentity.jks certificate).

C:\wls1211_dev\wlserver\server\bin>copy DemoIdentity.jks C:\wls1211_dev\wlserver\server\lib  Overwrite C:\wls1211_dev\wlserver\server\lib\DemoIdentity.jks? (Yes/No/All): Yes          1 file(s) copied.

Once that you have created the Weblogic Managed Server, you will be able to customize its properties by clicking on the Server Configuration | General tab. Once there, you can customize the server listening port and select as well the server Machine which is associated with this server.

Continue reading Configure Weblogic Managed Servers Properties

Within a Weblogic domain, server instances other than the Administration Server are referred to as Managed Servers. Managed Servers host the components and associated resources that constitute your applications—for example, JSPs and EJBs. When a Managed Server starts up, it connects to the domain’s Administration Server to obtain configuration and deployment settings.
Let’s see how to add a Managed Server from the Administration Console:

1.       Navigate to the Environment | Servers option and click on the “New” button.

2.       The New Server window will let you define the basic server properties. For the purpose of this example, we will choose as Server Name “WLSNode1” and enter 7003 as Server Port. Leave the “No, this is a stand-alone server” option selected in the lower part of the GUI (In Chapter 9 we will describe how to create a cluster from a set of managed nodes).

Choose Finish. This will take you to the Servers view which now includes the server WLSNode1 as shown by the following picture:

Before creating Weblogic Managed Servers, we will need to define a new Machine to host them. A Machine refers to the logical representation of the computer that is hosting one or more instances of Weblogic Servers. In order to create a new Machine, perform the following steps:

1. In the left pane of the Console, expand Environment and select Machines. The Machines table displays in the main panel showing all the machines defined in the domain.
2. Click on the Add button. The following screen will be displayed:

In the lower part of this form, you have the option to select the operating system where the machine is running. This has relevance especially if you are using Unix. (In one minute we will show the impact of this choice). Click Next.

As shown by the following screen, you need to select the properties that will be used to configure the Node Manager on this machine.

Click on Finish to complete the Machine creation. Once created a new Machine, the administration server will be able to use the Machine definition of the computer with Node Manager in order to start the remote servers.

As we said, by default the Oracle Weblogic console is deployed on demand (that is, on first request). If you want to have it deployed as part of the boot process, perform the following tasks:

1. Log on to the WebLogic console and click on your domain (e.g. base_domain), in the left navigation bar of the WLS console.

2. Open the Configuration tab and then the General sub-tab; deselect the checkbox labeled “Enable on-demand deployment of internal applications” and Click on the Save button.

Through the Administration Console, System administrators can easily perform all WebLogic Server management tasks without having to learn the low level API or the underlying management architecture. The Administration Server persists changes to attributes in the config.xml file for the domain you are managing.

In the following recipes we will learn how to move our first steps with the Administration Console; as we said, the Administration Console is accessible by default at the following address: http://localhost:7001/console.

Now type in the user and password you have entered in the server installation. Once logged in, here is how the Administration Console looks like:

As you can see, the Administration Console is composed of several panels; the most interesting ones for us are the following:

1.       The Change Center Panel

To provide secure and predictable means for distributing configuration changes in a domain, Weblogic Server uses a change management process that loosely resembles a database transaction. Therefore, you need to acquire the configuration with a Lock & Edit before performing changes on it and commit changes using the Release Configuration.

2.     The Domain Structure Panel

This panel is a tree that you can use to navigate into the application server’s resources. Click on any of the nodes in the Domain Structure tree to go to that page. Click the “+” (plus) icon in the Domain Structure to expand a node and the “-“(minus) icon to collapse the node. Once selected an item from the domain, the focus is on the Main panel window:

3.     The Main Panel

This is the core panel where you perform your administration tasks on your resources. Every operation is usually performed through intuitive wizards which are displayed in this panel.