Enabling parallel portlet rendering

You can configure parallel portlet rendering to optimize the response time of your portal, depending on your configuration. When portlets on a page are rendered sequentially, some portlets can delay output from other portlets to the client browser. For example, portlets that are waiting for a response from a remote service can cause such delays. Parallel portlet rendering can prevent this delay.

About this task

Enabling parallel portlet rendering provides a benefit if a high proportion of the portlets access remote locations to fetch the content that they render, for example by consuming WSRP services as remote portlets from a WSRP Producer.

Note: Parallel portlet rendering is intended for server side rendering only. It is not supported for client side rendering.

For portlets to be rendered parallel, the settings for both the portal and the individual portlets need to be set to enable parallel portlet rendering.

The default setting for the portal is that portlets cannot be rendered in parallel. In addition, the default setting for individual portlets is not to be rendered in parallel. An individual portlet needs to be enabled for parallel rendering, for example, by the portlet developer or the administrator. Therefore, if you enable the portal wide property for parallel portlet rendering, the portal renders only those portlets concurrently which have been configured accordingly. Portlets that are not enabled for parallel rendering are always rendered sequentially.

You can change the setting for a portlet to parallel rendering in the Manage Portlets portlet. Proceed by the following steps:

Procedure

Select Portal Administration > Portlet Management > Portlets.
Select the required portlet and click the Configure (wrench) icon. The portal displays the panel for configuring the portlet.
Mark the Enable parallel rendering check box to enable parallel rendering for the portlet.

What to do next

Alternatively you can also use the following parameter to enable parallel rendering of a portlet. You set this parameter as a configuration parameter in IBM portlets or as a read-only preference in standard portlets.

parallel = (false): When you set this parameter to true, you indicate that the portlet can be rendered in parallel with other portlets on the page. The default is false.

Note: Usually only some of the portlets that are configured for parallel rendering are actually rendered in parallel. Portlets for which the portal cannot provide a thread immediately are rendered sequentially. Therefore, in order to get the best performance, select carefully which portlet you configure for parallel rendering.

You can configure portal wide parallel portlet rendering globally for all markups, or individually for the markups of the client devices that display the pages.

To enable parallel rendering makes sense only for markups that can display all portlets on a page, such as HTML. Therefore, do not enable parallel rendering for markups that can only display a single portlet of a page at a time, such as WML.

You can change the portal wide settings for parallel portlet rendering in the portal WP Portlet Container Service. You use two different parameters for configuring parallel portlet rendering, depending on the type of portlets (JSR standard or IBM) you want to have rendered parallel:

For parallel rendering of local IBM portlets, enable the following parameter:
legacy.useParallelRendering.[markup] = (false)

Activates the portlet container functionality for parallel portlet rendering for the specified markup. Valid values are true or false . By default this parameter is set to false . If you omit the markup, the setting applies to all markups for which no specific setting has been defined.
For parallel rendering of local JSR portlets, or for remote portlets that you integrated in a WSRP Consumer portal, enable the following parameter:
std.useParallelRendering.[markup] = (false)

Activates the portlet container functionality for parallel portlet rendering for the specified markup. Valid values are true or false . By default this parameter is set to false . If you omit the suffix markup, the setting applies to all markups for which no specific setting has been defined.

The settings for configuring the parallel portlet rendering parameters are listed and explained in the following list:

false: Parallel rendering is disabled. This is the default. All portlets are rendered sequentially, even if they are enabled for parallel rendering.
true: Parallel rendering is enabled. All portlets which have parallel rendering enabled are rendered in parallel. Portlets that are not enabled for parallel rendering are rendered sequentially.