By default, new instances of the ServiceNow platform will be configured such that Homepage caching is enabled. In many cases, using Homepage caching can significantly improve performance of an instance, as the Homepage display will often be loaded from the instances internal cache rather than need to be re-rendered each time displayed.
However in some cases, this may not be the best behavior for an instance. If the Homepage itself is highly dynamic and subject to very frequent changes, it might be better to disable this feature to force the Homepage to be fully re-loaded each time it is to be displayed for an end-user.
This article will describe the steps to disable or re-enable the Homepage caching feature as well as describe some of the other system properties that can alter the homepage caching behavior.
To disable this Homepage caching as performed on the instance, the following steps should be followed:
Log into the instance with an account having admin rights on the instance.
Browse to the following location on the instance using the Menu Navigator: Homepage Admin -> Properties.
The properties page associated to Homepage settings should appear. Locate the checkbox on the page titled Enable homepage render cache.
Set this option such it is not checked (set to No) to disable the Homepage caching feature.
Click the Save button at the bottom of the Homepage properties page or the corresponding Save button at the upper right corner of the same properties page.
This setting will cause the Homepage cache not to be used, and each request for a homepage will request the Homepage and data from the server on each reload or refresh of the Homepage.
To deactivate this Homepage caching on an instance in which Homepage caching is currently de-activated, simply go to the same properties page and ensure the Enable homepage render cache option is checked (Yes) and click one of the Save buttons found on the Homepage Properties page.
There are a few other properties associated with Homepage caching that can also be adjusted which will significantly modify the way the Homepage caching works. Note that if the Homepage caching is disabled (as per the procedures given above), these settings will not modify any behavior on the instance.
The first such property is titled Maximum amount of time an entry stays in the render cache. This property will adjust the amount of time (in seconds) for which a specific entry in the Homepage cache will be removed from the cache and which will then force the Homepage to reloaded when requested by an end user on the instance. The default setting for this property is 60, which indicates that a page will remain in the homepage cache for a maximum of 60 seconds before being considered invalid (regardless if the actual source data for the Homepage has changed), at which time it will be removed from the cache.
Another property which can modify the behavior of the Homepage cache is the property with the title Enable aggressive caching. This property is unchecked (set to a value of No) by default on a new instance. If this setting is changed to true, the instance will never remove a cached Homepage unless the underlying data for the homepage changes. This setting will override any setting for the Maximum amount of time an entry stays in the render cache.
Note that the properties that control these settings can also be modified directly from the corresponding system property in the list of sys_properties on the same instance.
This chart shows the internal ServiceNow property name that is related to which setting:
|Title as Found on Homepage Admin Properties Page||Internal ServiceNow Property Name||Allowable Data Types|
|Enable homepage render cache||glide.render.cache.enable||true or false|
|Maximum amount of time an entry stays in the render cache||glide.render.cache.max.age||Integer number|
|Enable aggressive caching||glide.render.cache.aggressive||true or false|