Operating Systems: AIX, HP-UX, Linux, Solaris, Windows, z/OS
Creating and configuring ODRs
The on demand router (ODR) is an intelligent HTTP and Session Initiation Protocol (SIP) proxy server in WebSphere® Virtual Enterprise. The ODR is the point of entry into a WebSphere Virtual Enterprise environment and is a gateway through which HTTP requests and Session Initiation Protocol (SIP) messages flow to back-end application servers. You can configure the ODR to determine how it handles failure scenarios and how it tunes certain work requests.
About this task
The ODR can momentarily queue requests for less important applications in order to allow request from more important applications to be handled more quickly or to protect back-end application servers from being overloaded. The ODR is aware of the current location of a dynamic cluster instance, so that requests can be routed to the correct endpoint. The ODR can also dynamically adjust the amount of traffic sent to each individual server instance based on process utilization and response times. By default, the ODR binds to ports 80 and 443 for listening on HTTP and HTTPs, which requires running the ODR as a root user. If you want to run the ODR as a non-root user, change the PROXY listening ports to values greater then 1024.
Procedure
- Creating ODRs
An ODR is a proxy server with advanced capabilities that WebSphere Virtual Enterprise uses to route work to server nodes. Note that the configuration of the ODR in the DMZ is not supported. To configure ODRs to perform a SSL offload, see Configure SSL offload for all HTTPS traffic. For information on other custom properties, see On demand router system and custom properties.
- Follow the WebSphere Network Deployment instructions in the Proxy server settings topic for most of the instructions to configure ODRs. See Configure ODRs for WebSphere Virtual Enterprise specific fields. Avoid trouble: In the WebSphere Extended Deployment administrative console, use the following path to define the configuration of the ODR: Servers > On demand routers > ODR_name > On Demand Router Settings > On Demand Router Properties. gotcha
- Configure SSL offload for all HTTPS traffic
By default, the ODR matches the incoming protocol to the outgoing protocol. For inbound HTTP requests, the request is forwarded over outbound HTTP. For inbound HTTPS, the request is forwarded over outbound HTTPS. This default behavior can either be changed for all HTTP and HTTPS traffic that is handled by the ODR, or on a per-Web module basis.
- On demand router system and custom properties
You can use on demand router (ODR) custom properties to change the behavior of your ODR. For example, you can change the error code that the ODR returns when messages are rejected because of processor or memory overload.
- Configure a Web server as a trusted proxy server A Web server should be configured as a trusted secure proxy because a trusted security proxy is allowed to pass information such as the virtual host name, or user identity to the ODR in private HTTP headers.
- Optional: Defining routing policies for generic server clusters
- Defining a service policy
Routing and service policies for SIP are defined at the ODRs.
What to do next
Configure the middleware servers and dynamic clusters for your environment.
Subtopics
Creating ODRs
Configure ODRs
Configure a Web server as a trusted proxy server
Configure SSL offload for all HTTPS traffic
Defining routing policies for generic server clusters
Defining service policies for generic server clusters
Next topic
Adding middleware servers to configurationsNext topic
Adding middleware servers to configurationsNext topic
Creating dynamic clusters
Related concepts
Overview of request flow prioritization
Related tasks
Preparing the hosting environment for dynamic operations
Related reference
createodr.jacl script