15.12 Tuning Connections to Origin Servers

Each Oracle Traffic Director virtual server acts as a reverse proxy through which clients outside the network can access critical data and applications hosted on multiple origin servers in the back end. This section describes the parameters that you can tune to improve the performance of Oracle Traffic Director as a reverse-proxy server.

Enable keep-alive: This parameter indicates whether the Oracle Traffic Director virtual server should attempt to use persistent connections to the origin server or create a new connection for each request. It is enabled by default.
Keep-alive timeout: This parameter specifies the maximum duration, in seconds, for which a persistent connection can be kept open. The default timeout duration is 29 seconds.
Idle timeout: This parameter specifies the maximum duration, in seconds, for which a connection to the origin server can remain idle. The default duration is 300 seconds.
Always use keep-alive: This parameter indicates whether the Oracle Traffic Director virtual server can reuse existing persistent connections to origin servers for all types of requests. If this parameter is not enabled (default), the Oracle Traffic Director virtual server attempts to use persistent connections to the origin server only for the GET, HEAD, and OPTIONS request methods.
Proxy buffer size: This parameter specifies the size of the buffer in which Oracle Traffic Director stores data received from the origin server, before sending the data to the client. Larger the buffer, lower is the number of write system calls. The default size of the proxy buffer is 16 kilobytes.

The reverse-proxy settings for connections between an Oracle Traffic Director virtual server and an origin server pool are defined in routes. To change the reverse-proxy settings, you should edit the routes by using either the administration console or the CLI.

Note:

In the current release, you cannot configure the proxy buffer size by using the administration console or the CLI.

To configure the proxy buffer size for a route, do the following:

Add the proxy-buffer-size parameter to the http-client-config server application function (SAF) in the vs_name-obj.conf configuration file of the virtual server that contains the route that you want to edit.

The vs_name-obj.conf file is located in the following directory:
```
INSTANCE_HOME/net-config_name/config
```
The following is an example of a route (route1) for which the proxy-buffer-size and other reverse-proxy parameters have been configured.
```
<Object name="route1">
ObjectType fn="http-client-config" keep-alive-timeout="31" always-use-keep-alive="true" keep-alive="false" timeout="360" proxy-buffer-size="32768"
Route fn="set-origin-server" origin-server-pool="origin-server-pool-1"
</Object>
```
Save and close the vs_name-obj.conf file.
Run the pull-config command to update the configuration store on the administration server and to give effect to this change in all the instances of the configuration.
```
tadm> pull-config --config=config_name node
```
node is the name of the node on which you configured the proxy buffer size.

For more information about the http-client-config server application function (SAF), see the Oracle Traffic Director Configuration Files Reference.

Editing Routes Using the Administration Console

To edit routes by using the administration console, do the following:

Log in to the administration console, as described in Section 2.3.2, "Accessing the Administration Console."
Click the Configurations button that is situated at the upper left corner of the page.

A list of the available configurations is displayed.
Select the configuration for which you want to edit routes.
In the navigation pane, expand Virtual Servers, expand the name of the virtual server for which you want to edit routes, and select Routes.

The Routes page is displayed. It lists the routes that are currently defined for the virtual server.
Click the Name of the route that you want to edit.

The Route Settings page is displayed.

Specify the reverse-proxy parameters in the following fields on the Route Settings page:

Section of the Route Settings Page	Field/s
General Settings	Keep Alive Keep Alive Timeout
Advanced Settings: Client Configuration for Connections with Origin Servers	Always Use Keep Alive Idle Timeout

Section of the Route Settings Page

Field/s

General Settings

Keep Alive

Keep Alive Timeout

Advanced Settings: Client Configuration for Connections with Origin Servers

Always Use Keep Alive

Idle Timeout

On-screen help and prompts are provided for all of the parameters.

When you change the value in a field or tab out of a text field that you changed, the Save button near the upper right corner of the page is enabled.

At any time, you can discard the changes by clicking the Reset button.

After making the required changes, click Save.
- A message, confirming that the updated configuration was saved, is displayed in the Console Messages pane.
- In addition, the Deployment Pending message is displayed at the top of the main pane. You can either deploy the updated configuration immediately by clicking Deploy Changes, or you can do so later after making further changes as described in Section 4.3, "Deploying a Configuration."

Configuring Routes Using the CLI

To change the properties of a route, run the set-route-prop command. The following are the names of the reverse-proxy parameters described earlier:

keep-alive-timeout
always-use-keep-alive
use-keep-alive
timeout

For example, the following command changes the keep-alive timeout duration for the route route1 in the virtual server soa.example.com of the configuration soa to 30 seconds.

tadm> set-route-prop --config=soa --vs=soa.example.com --rule=route1 keep-alive-timeout=30

For the updated configuration to take effect, you should deploy it to the Oracle Traffic Director instances by using the deploy-config command.

For more information about the CLI commands mentioned in this section, see the Oracle Traffic Director Command-Line Reference or run the commands with the --help option.