5.4 Configuring a Pin List

A pin list contains URL patterns for identifying objects on the Web. The Access Gateway uses the list to prepopulate the cache, before any requests have come in for the content. This accelerates user access to the content because it is retrieved from a local cache rather than from an exchange with the Web server, which would read it from disk.

You can use the pin list to specify the following:

The pin list is global to the Access Gateway and affects all protected resources. The objects remain in cache until their normal cache limits are reached or they are bumped out by more recently requested objects.

To configure a pin list:

  1. In the Administration Console, click Devices > Access Gateways > Edit > Pin List.

    Configuring a pin list
  2. Select the Enable Pin List option to enable the use of pinned objects. If this option is not selected, the pinned objects in the pin list are not used.

  3. In the Pin List section, click New.

  4. Fill in the following fields.

    URL Mask: Specifies the URL pattern to match. For more information, see URL Mask.

    Pin Type: Specifies how the URL is to be used to cache objects. Select from Normal and Bypass. For more information, see Pin Type.

  5. To save the list item, click OK.

  6. To save your changes to browser cache, click OK.

  7. To apply the changes, click the Access Gateways link, then click Update > OK.

URL Mask

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.

The Access Gateway processes the masks in the pin list in order of specificity. A mask containing a hostname 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.

The Access Gateways recognizes four levels of specificity, using the following format:

Level

Examples

hostname

http://www.foo.gov/documents/picture.gif
http://www.foo.gov/documents/*
http://www.foo.gov
foo.gov/documents/*
foo.gov/*

All of these are classified as hostnames, and they are ordered by specificity. The first item in the list is considered the most specific and is processed first. The last item is the most general and is processed last.

path

/documents/picture.gif
/documents/pictures.gif/*
/documents/*

Path entries are processed after hostnames. A leading forward slash must always be used when specifying a path, and the entry that follows must always reference the root directory of the Web server. In these examples, documents is the root directory.

The /* at the end of the path indicates that the entry is a directory. Its absence indicates that the entry is a file. In these examples, picture.gif is a file and pictures.gif/* and documents/* are directories.

If you enter a path without the trailing *, the path matches only the directory. With the trailing *, the path matches everything in the directory and its subdirectories.

These path entry examples are ordered by specificity. The objects in the /documents/picture.gif directory are processed before the objects in the /documents directory.

filename

/picture.gif
/widget.js

Filenames are processed after paths. A leading forward slash must always be used when specifying a filename. If a path is included with a filename, the path must start with the root directory of the Web server, and the entry is processed as a path entry, not as a filename entry.

file extension

/*.gif
/*.js
/*.htm

File extensions are processed last. They consist of a leading forward slash, an asterisk, a period, and a file extension.

Specific rules have precedence over less specific rules. Thus, objects matched by a more specific rule are always processed according to its conditions. If a less specific rule also matches the object, the less specific rule is ignored for the object. For example, assume the following two entries are in the pin list:

URL Mask

Pin Type

Pin Links

http://www.foo.gov/documents/*

normal

1

www.foo*

bypass

N/A

The first entry, because it is most specific, caches the pages in the documents directory and follows any links on those pages and caches the linked pages. The second entry does not affect what the first entry caches, but it prevents any other domain extensions such as .com, .net, or .org whose DNS names begin with www.foo from being cached.

Pin Type

The pin type specifies how the Access Gateway caches objects that match the URL mask.