Manual Chapter : Immediately Caching Dynamic Objects

Applies To:

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BIG-IP AAM

  • 12.1.5, 12.1.4, 12.1.3, 12.1.2, 12.1.1, 12.1.0, 11.6.5, 11.6.4, 11.6.3, 11.6.2, 11.6.1
Manual Chapter

Immediately Caching Dynamic Objects

Overview: Caching an object on first hit

The BIG-IP® system provides you with the ability to cache an object on the first cache hit, that is, the first time that an object is seen by the BIG-IP system. Typically, the BIG-IP system waits until the object is known to be popular, allowing a limited number of hits against the original content. Caching the object on first hit, however, causes the BIG-IP system to immediately cache the object, even if it is not popular. You only want to apply this setting for highly dynamic objects (for example, stock quotes provided by a stock ticker) that you want to cache for a limited time to offload the origin web server. If you use this setting on content that omits a Content-Length header, or if the object is an HTML, JavaScript (JS), or cascading style sheet (CSS) object, a significant degradation in performance can occur.

Caching an object on first hit

You can cache an object when the cache receives that object for the first time. Typically, you want to apply this setting only for highly dynamic objects, for example, stock quotes provided by a stock ticker.
Important: A significant degradation in performance can occur when using this setting on an HTML, JavaScript (JS), or cascading style sheet (CSS) object, or content that omits a Content-Length header.
  1. On the Main tab, click Acceleration > Web Application > Policies .
    The Policies screen displays a list of existing acceleration policies.
  2. Click the name of a user-defined acceleration policy.
  3. Click a node in the Policy Tree.
  4. From the Matching Rules menu, choose Acceleration Rules.
  5. Select the Cache content on first hit check box.
    Important: The Queue Parallel Requests check box must be clear to enable the Cache content on first hit setting. If the Queue Parallel Requests check box is selected, the Cache content on first hit setting is disabled.
  6. Optional: For the Object Min Size setting, clear the Use Profile Setting check box, and type the minimum object size (in bytes) to cache, overriding the Web Acceleration profile setting.
  7. Optional: For the Object Max Size setting, clear the Use Profile Setting check box, and type the maximum object size (in bytes) to cache, overriding the Web Acceleration profile setting.
  8. Click Save.
The BIG-IP system caches an object when the cache receives that object for the first time.

Disabling the Caching an object on first hit setting

You can disable the ability of the system to cache an object when the cache receives that object for the first time.
  1. On the Main tab, click Acceleration > Web Application > Policies .
    The Policies screen displays a list of existing acceleration policies.
  2. Click the name of a user-defined acceleration policy.
  3. From the Matching Rules menu, choose Acceleration Rules.
  4. On the menu bar, click Responses Cached.
  5. Clear the Cache content on first hit check box.
  6. Click Save.
  7. Publish the acceleration policy.
    1. Click Publish.
    2. In the Comment field, type a description.
    3. Click Publish Now.
Caching an object on first hit is disabled.