Last-Modified Factor

The last-modified factor helps determine the likelihood that a document will change based on the previous changes that have been noted.

The last-modified factor is a fraction between .02 and 1.0. It is multiplied by the interval between a document’s actual last modification and the time the last up-to-date check was performed on the document. The resulting number is compared with the time since the last up-to-date check. If the number is smaller than the time interval, the document has not expired. If, however, the number is larger than the time interval, then the document has expired and a new version is obtained from the origin server.

The last-modified factor enables you to ensure that recently changed documents are checked more often than old documents.

You should set a last-modified factor between 0.1 and 0.2.