website snapshot not update and update the
on this issue, the author made a test, find love Shanghai snapshot not update does not mean love Shanghai crawl the page through the web log analysis of love Shanghai spiders to crawl home page, general HTTP status code will return 200 or 304:
love Shanghai shortly before the official published a snapshot of love Shanghai, love Shanghai general explained the snapshot update and backward reason, and directly pointed out that "the website snapshot does not have any relationship with the site weight".
in the second love Shanghai grab this URL, according to the HTTP protocol, the server will be the first to send If-Modified-Since HTTP header information to access terminal, check this file is not modified, if not modified to return the content is empty the 304 status code, save the amount of data transmission.
due to the popularity of Shanghai based dragon knowledge is not enough, when exchanging Links, there are still a lot of people take snapshot website as one of the main reference standard, even if the website ranking, PR high, in the love of Shanghai official statement to the other side, the other side is also very helpless to the sentence above leadership requires no way.
is a static page, spiders love Shanghai first time to grab a URL address, the server returns the status code is 200, and will record the Last-Modified attribute of the tag page (HttpFox test page last modified time, can be used in Firefox before the Shanghai dragon plug-in introduced), such as
observation of some enterprise website, found about the site keywords ranking, is also the site content is not updated, but some love Shanghai snapshot is always the next day, some fixed stop in one day.
is the first snapshot of web page is a dynamic web page, even if not update the content, not the Last-Modified attribute, each return is also 200 status code, so the next day will love Shanghai.
second a snapshot of stagnation site is static page content is not updated, when the second love Shanghai spiders crawl will return 304 status code, on behalf of a web site is not updated, so snapshot date will remain in the Last-Modified date, and this is also the reason why love Shanghai snapshot not update the.
now, love Shanghai snapshot in Shanghai Longfeng role is mainly reflected in the exchange Links, so I want to let the new website snapshot, dynamic home page or home page to periodically generate static.