Cisco Cisco Collaboration Server Dynamic Content Adapter
DCA 2.01 Administration and Configuration Guide
About DCA Caching 78
About DCA Caching
The DCA includes these mechanisms for storing the content it receives from Web
content servers:
content servers:
• The DCA Cache
• The Copy Server
• The Static Cache
The DCA Cache
Pages returned to the DCA from a Web content server are stored in the DCA cache.
The DCA cache allows the DCA to store and return pages quickly from memory. The
DCA cache only stores the text of served pages; the DCA cache does not store non-
text file types such as images, executables, archives, PDFs and so on.
The DCA cache allows the DCA to store and return pages quickly from memory. The
DCA cache only stores the text of served pages; the DCA cache does not store non-
text file types such as images, executables, archives, PDFs and so on.
The Response and Output Cache
There are actually two DCA caches: the Response cache and the Output cache.
• Response Cache: When a page is initially returned to the DCA from a Web
content server, the DCA parses the page, redirects all links on the page to the
DCA, and then stores the page as a Java object in its Response cache.
DCA, and then stores the page as a Java object in its Response cache.
• Output Cache: After a page is stored in the Response cache, the DCA
reconstructs it and passes it to the Output cache, where it is available to users.
Subsequent requests for the page are satisfied directly from the Output cache.
Subsequent requests for the page are satisfied directly from the Output cache.
Cache Size and Page Expiration
The size of each cache is determined by a configurable property. By default, each
cache stores up to 50 pages. When the maximum size is reached, new pages coming
into the cache cause older pages to be forced out. When an unexpired page is forced
from the Response cache, it is written to the Cisco Copy Server, where it remains
available to users until it expires.
cache stores up to 50 pages. When the maximum size is reached, new pages coming
into the cache cause older pages to be forced out. When an unexpired page is forced
from the Response cache, it is written to the Cisco Copy Server, where it remains
available to users until it expires.
Pages stored in the DCA cache expire based on a configurable timeout. Once a page
has expired, it is unavailable, even if it still remains in the cache. Subsequent
requests for an expired page are satisfied from a Web content server.
has expired, it is unavailable, even if it still remains in the cache. Subsequent
requests for an expired page are satisfied from a Web content server.