DMZ with Two Firewall Configuration

9-16 Using Clusters for Oracle WebLogic Server Figure 9–9 Application Components Have Restricted Access Through Firewall

9.5.2 Additional Security for Shared Databases

If you use a single database that supports both internal data and data for externally-available Web applications, you should consider placing a hard boundary between the object layer that accesses your database. Doing so simply reinforces the DMZ boundaries described in Section 9.5.1, Basic Firewall for Proxy Architectures, by adding an additional firewall.

9.5.2.1 DMZ with Two Firewall Configuration

The configuration shown in Figure 9–10 places an additional firewall in front of a database server that is shared by the Web application and internal trusted clients. This configuration provides additional security in the unlikely event that the first firewall is breached, and a hacker ultimately gains access to servers hosting the object tier. Note that this circumstance should be extremely unlikely in a production environment—your site should have the capability to detect and stop a malicious break-in long before a hacker gains access to machines in the object layer. Cluster Architectures 9-17 Figure 9–10 DMZ with Two Firewalls Architecture In the above configuration, the boundary between the object tier and the database is hardened using an additional firewall. The firewall maintains a strict application-level policy that denies access to all connections except JDBC connections from WebLogic Servers hosting the object tier. 9-18 Using Clusters for Oracle WebLogic Server 10 Setting up WebLogic Clusters 10-1 10 Setting up WebLogic Clusters The following sections contain guidelines and instructions for configuring a WebLogic Server cluster: ■ Section 10.1, Before You Start ■ Section 10.2, Cluster Implementation Procedures

10.1 Before You Start

This section summarizes prerequisite tasks and information for setting up a WebLogic Server cluster.

10.1.1 Understand the Configuration Process

The information in this section will be most useful to you if you have a basic understanding of the cluster configuration process and how configuration tasks are accomplished. For information about the configuration facilities available in WebLogic Server and the tasks they support, see Section 4, Understanding Cluster Configuration.

10.1.2 Determine Your Cluster Architecture

Determine what cluster architecture best suits your needs. Key architectural decisions include: ■ Should you combine all application tiers in a single cluster or segment your application tiers in separate clusters? ■ How will you balance the load among server instances in your cluster? Will you: – Use basic WebLogic Server load balancing, – Implement a third-party load balancer, or – Deploy the Web tier of your application on one or more secondary HTTP servers, and proxy requests to it? ■ Should you define your Web applications De-Militarized Zone DMZ with one or more firewalls? To guide these decisions, see Section 9, Cluster Architectures, and Section 5, Load Balancing in a Cluster. The architecture you choose affects how you set up your cluster. The cluster architecture may also require that you install or configure other resources, such as load balancers, HTTP servers, and proxy plug-ins.