8.3 Modifying a Virtual Server

You can modify virtual servers by using either the administration console or the CLI.

Note:

When you modify a virtual server, you are, in effect, modifying a configuration. So for the new virtual-server settings to take effect in the Oracle Traffic Director instances, you should redeploy the configuration as described in Section 4.3, "Deploying a Configuration."
The CLI examples in this section are shown in shell mode (tadm>). For information about invoking the CLI shell, see Section 2.3.1, "Accessing the Command-Line Interface."

Modifying a Virtual Server Using the Administration Console

To modify a virtual server 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 modify virtual servers.
In the navigation pane, select Virtual Servers.

The Virtual Servers page is displayed. It shows a list of the virtual servers defined for the configuration.
Select the virtual server that you want to modify.

The Virtual Server Settings page is displayed. On this page, you can do the following:
- Enable and disable the virtual server.
- Add, remove, and change host patterns served by the virtual server. For more information about how Oracle Traffic Director uses host patterns, see the "Before You Begin" section.
- Add and remove HTTP listeners. For information about creating HTTP listeners, see Section 10.1, "Creating a Listener."
- Enable SSL/TLS, by associating an RSA or an ECC certificate (or both) with the virtual server. For more information, see Section 11.2.3, "Associating Certificates with Virtual Servers."
- Configure the virtual server to serve instance-level statistics in the form of XML and plain-text reports that users can access through a browser. Note that the statistics displayed in the XML and plain-text reports are for the Oracle Traffic Director instance as a whole and not specific to each virtual server. For more information, see Section 13.3, "Configuring URI Access to Statistics Reports."
- The default language for messages is English. If required, this can be set to other languages that Oracle Traffic Director supports.
- Specify error pages that the virtual server should return to clients for different error codes. This is necessary only if you do not wish to use the default error pages and would like to customize them.
  
  To specify error codes and error pages of your choice, first create html pages that you would like displayed for specific error codes and save them to any directory that can be accessed by the administration server. Next, on the Virtual Server Settings page, in the Error Pages section, click New Error Page.
  
  In the New Error Page dialog box that appears, select an error code and enter the full path to the error page for that particular error code. In addition to the error codes that are provided, you can create your own custom error code by clicking Custom Error Code and entering a value for the same. When done, click Create Error Page.
- Enable and quality of service limits—the maximum speed at which the virtual server should transfer data to clients and the maximum number of concurrent connections that the virtual server can support.
In the navigation pane, under the Virtual Servers node, you can select the following additional categories of settings for the virtual server. The parameters relevant to the selected category are displayed in the main pane.
- Routes: Create, change, and delete rules for routing requests to origin servers. For more information, see Section 8.4, "Configuring Routes."
- Caching: Create, change, and delete rules for caching responses received from origin servers. For more information, see Section 15.7.4, "Configuring Caching Parameters."
- Request Limits: Create, change, and delete rules for limiting the number and rate of requests received by the virtual server. For more information, see Section 11.9, "Preventing Denial-of-Service Attacks."
- Compression: Create, change, and delete rules for compressing responses from origin servers before forwarding them to the clients. For more information, see Section 15.11, "Enabling and Configuring Content Compression."
- Logging: Define a server log file and location that is specific to the virtual server. For more information, see Section 12.3, "Configuring Log Preferences."
- Webapp Firewall Ruleset: Enable or disable webapp firewall rule set, specify rule set patterns and install rule set files. For more information, see Section 11.7, "Managing Web Application Firewalls."
Specify the parameters that you want to change.

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."

Modifying a Virtual Server Using the CLI

The CLI provides several commands (see Table 8-1) that you can use to change specific parameters of a virtual server.

Table 8-1 CLI Commands for Modifying a Virtual Server

Task/s	CLI Command/s
Enable or disable a virtual server; change the host, the HTTP listener, name and location of the log file; enable SSL/TLS by associating an RSA, or an ECC certificate, or both (see also: Section 11.2.3, "Associating Certificates with Virtual Servers" and Section 12.3, "Configuring Log Preferences"	`set-virtual-server-prop`
Create and manage caching rules (see Section 15.7, "Tuning Caching Settings"	`create-cache-rule` `list-cache-rules` `delete-cache-rule` `get-cache-rule-prop` `set-cache-rule-prop`
Create and manage compression rules (see Section 15.11, "Enabling and Configuring Content Compression")	`create-compression-rule` `set-compression-rule-prop` `delete-compression-rule` `list-compression-rules` `get-compression-rule-prop`
Change QoS settings	`set-qos-limits-prop` `get-qos-limits-prop`
Change request limiting settings (see Section 11.9, "Preventing Denial-of-Service Attacks")	`create-request-limit` `delete-request-limit` `get-request-limit-prop` `list-request-limits` `set-request-limit-prop`
Create and manage routes (see Section 8.4, "Configuring Routes")	`create-route` `list-routes` `delete-route` `set-route-prop` `get-route-prop`
Create and manage error pages	`create-error-page` `delete-error-page` `list-error-pages`

For example, the following command changes the location of the error log file for the virtual server soa to /home/log/errors.log.

tadm> set-virtual-server-prop --config=soa --vs=soa log-file=/home/log/errors.log
OTD-70201 Command 'set-virtual-server-prop' ran successfully.

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.