Pinned objects remain in cache indefinitely unless it fills up. This ensures that they are available from cache and will not be bumped out by more recently requested objects.
The pin list contains URL patterns for identifying objects on the Web. You configure each URL pattern in the list with specific handling instructions, as explained in the following sections.
To configure the appliance's pin lists, do the following:
In the browser-based tool click Cache > Management.
Check Enable Pin List.
From the drop down list box, select a default Refresh Frequency.
NOTE: If you selected Timed Interval, enter a default refresh time.
For more information see Refresh Frequency/Time.
To add a URL Mask to the pin list, do the following:
Click Insert.
Enter the URL mask.
For more information, see URL Mask.
From the drop down list, select the pin type.
For more information, see Pin Type.
From the drop down list, select the number of pin links.
For more information, see Pin Links .
If you want to pin image files that reside on a different host than the page requested, check the Pin Images check box.
To add more URL Masks, complete steps 1 through 5 above until you are done.
Click Apply to save the changes.
To modify an existing URL mask, do the following:
To exit without applying changes, do the following:
To disable the pin list without deleting your list, do the following:
The list grays out, indicating the list is disabled.
The URL mask can contain complete or partial URL patterns. A single URL mask might apply to a large set of URLs, or it might be so specific that only a single file on the Web matches it. For more information, see Pin List Examples.
The appliance processes the masks in the pin list in order of specificity. A mask containing a host name is more specific than a mask that specifies only a file type. The action taken for an object is the action specified for the first mask that the object matches. For more information, see How URL Masks Are Processed.
If the mask contains an asterisk, only the pin type can be specified. The Pin Links, Pin Images, and Refresh Frequency/Time options are not available for URLs containing this wildcard. Objects matching a mask with an asterisk are not automatically downloaded, but are pinned in cache only as individually requested.
The Pin Type options specifies whether and how the appliance will cache objects that match the URL mask:
Normal: Excelerator handles objects matching the mask in the same way it handles any other requested objects. In other words, objects are cached but not pinned.
Administrators often use this pin type in combination with a broad URL mask that has a bypass pin type. This allows them to insulate specific objects from the effects of the bypass rule.
For example, you could specify a URL mask of /*.jpg with a pin type of bypass and a second URL mask of www.foo.gov/graphics/*.jpg with a pin type of normal. The result would be that the .jpg files in the graphics directory on the foo.gov Web site would be cached as requested. They would not, however, be pinned in cache. Assuming there were no other URL masks in the pin list, all other .jpg graphics would not be cached due to the first URL mask.
Cache: Excelerator keeps the pinned objects in cache as long as possible, although they might be written to the appliance's hard disk.
Memory: Excelerator keeps the pinned objects in memory as long as possible, writes them to disk when memory gets too full, and places them back in memory as soon as they are requested by a user of the cache.
Bypass: Excelerator does not cache the objects. In other words, you can use this option to prevent objects from being cached.
The Pin Links option specifies how many link levels Excelerator will follow the pin type rule you've established. Selecting levels 1 or 2 causes all linked objects, including the images on the host, to be downloaded and cached when the pin list is applied to the appliance configuration, and then to be periodically refreshed as specified.
For example, if the requested object is an HTML page and you have specified a pin links level of 1, the HTML page along with all the items linked from the page will be downloaded and cached when the pin list is applied. These cached objects will also be refreshed at the refresh frequency and time specified.
To use levels 1 or 2, you must specify an absolute address that includes the scheme, host, and path for the URL mask, such as http://www.foo.gov/documents/. The tool will let you insert masks that do not meet this requirement, but the entries are removed when you click Apply.
IMPORTANT: Attempting to include an asterisk wildcard immediately hides this option.
The Pin Image option is used to pin image files that reside on a different host than the page requested. It works in conjunction with the Pin Links option, which specifies how many levels of links Excelerator will follow when downloading a page.
For example, if the requested HTML page uses images that reside on another host and you have checked this option, the HTML page will be cached along with all the image files associated with the page, including those on the other host. If you have also specified a pin link level, images on the linked pages that reside on another host will also be pinned.
On the other hand, if the Pin Images option is not checked, Excelerator only pins the images that reside on the same host as the requested page.
The Refresh Frequency/Time option lets you specify a refresh frequency and time for the URL that is different from the default values shown above the pin list.