One thing I love about Twitter is the instant feedback. For the past few weeks I’ve been seeing lots of 404 requests like this: http://perishablepress.com/humans.txt http://perishablepress.com/humans.txt http://perishablepress.com/humans.txt At first I thought it was some skript kiddie getting creative, you know as a play on the robots.txt file, which is also located in the root of many websites. So it seemed interesting enough to tweet about: Read more »
Yes you can have multiple sitemaps for your site. Create the sitemaps you need, and then specify them in your robots.txt file. For example, here are the robots.txt directives for the two sitemaps used here at Perishable Press: Read more »
Cleaning up my files during the recent redesign, I realized that several years had somehow passed since the last time I even looked at the site’s robots.txt file. I guess that’s a good thing, but with all of the changes to site structure and content, it was time again for a delightful romp through robots.txt. Read more »
One of my favorite security measures here at Perishable Press is the site’s virtual Blackhole trap for bad bots. The concept is simple: include a hidden link to a robots.txt-forbidden directory somewhere on your pages. Bots that ignore or disobey your robots rules will crawl the link and fall into the trap, which then performs a WHOIS Lookup and records the event in the blackhole data file. Once added to the blacklist data file, bad bots immediately are denied access to your site. I call it the “one-strike” rule: bots have one chance to follow the robots.txt protocol, check the […] Read more »
If you’ve been keeping an eye on your 404 errors recently, you will have noticed an increase in requests for nonexistent mobile files and directories, especially over the past year or so. The scripts and bots requesting these files from your server seem to be looking for a mobile version of your site. Unfortunately, they are wasting bandwidth and resources in the process. It has become common to see the following 404 errors constantly repeated in your log files: http://domain.tld/apple-touch-icon.png http://domain.tld/iphone http://domain.tld/mobile http://domain.tld/mobi http://domain.tld/m So some bot comes along, assumes that your site includes a mobile version, and then tries […] Read more »
There are several ways to instruct Google to stay away from various pages in your site: Robots.txt directives Nofollow attributes on links Meta noindex/nofollow directives X-Robots noindex/nofollow directives ..and so on. These directives all function in different ways, but they all serve the same basic purpose: control how Google crawls the various pages on your site. For example, you can use meta noindex to instruct Google not to index your sitemap, RSS feed, or any other page you wish. This level of control over which pages are crawled and indexed is helpful, but what if you need to control how […] Read more »
I really hate bad robots. When a web crawler, spider, bot — or whatever you want to call it — behaves in a way that is contrary to expected and/or accepted protocols, we say that the bot is acting suspiciously, behaving badly, or just acting stupid in general. Unfortunately, there are thousands — if not hundreds of thousands — of nefarious bots violating our websites every minute of the day. For the most part, there are effective methods available enabling us to protect our sites against the endless hordes of irrelevant and mischievous bots. Such evil is easily blocked with […] Read more »
There are two possibilities here: Yahoo!’s Slurp crawler is broken or Yahoo! lies about obeying Robots directives. Either case isn’t good. Slurp just can’t seem to keep its nose out of my private business. And, as I’ve discussed before, this happens all the time. Here are the two most recent offenses, as recorded in the log file for my blackhole spider trap: Read more »
Hmmm.. Let’s see here. Google can do it. MSN/Live can do it. Even Ask can do it. So why oh why can’t Yahoo’s grubby Slurp crawler manage to adhere to robots.txt crawl directives? Just when I thought Yahoo! finally figured it out, I discover more Slurp tracks in my Blackhole trap for bad spiders: Read more »
I need your help! I am losing my mind trying to solve another baffling mystery. For the past three or four months, I have been recording many 404 Errors generated from msnbot, Yahoo-Slurp, and other spider crawls. These errors result from invalid requests for URLs containing query strings such as the following: http://perishablepress.com/press/page/2/?tag=spam http://perishablepress.com/press/page/3/?tag=code http://perishablepress.com/press/page/2/?tag=email http://perishablepress.com/press/page/2/?tag=xhtml http://perishablepress.com/press/page/4/?tag=notes http://perishablepress.com/press/page/2/?tag=flash http://perishablepress.com/press/page/2/?tag=links http://perishablepress.com/press/page/3/?tag=theme http://perishablepress.com/press/page/2/?tag=press ..plus hundreds and hundreds more 1. The URL pattern is always the same: a different page number followed by a query string containing one of the tags used here at Perishable Press, for example: “/?tag=something”. The problem is that there are […] Read more »
Controlling the spidering, indexing and caching of your (X)HTML-based web pages is possible with meta robots directives such as these: <meta name=”googlebot” content=”index,archive,follow,noodp”/> <meta name=”robots” content=”all,index,follow”/> <meta name=”msnbot” content=”all,index,follow”/> I use these directives here at Perishable Press and they continue to serve me well for controlling how the “big bots” 1 crawl and represent my (X)HTML-based content in search results. For other, non-(X)HTML types of content, however, using meta robots directives to control indexing and caching is not an option. An excellent example of this involves directing Google to index and cache PDF documents. The last time I checked, meta tags […] Read more »
Yup, ‘ol Slurp is at it again, flagrantly disobeying specific robots.txt rules forbidding access to my bad-bot trap, lovingly dubbed the “blackhole.” As many readers know, this is not the first time Yahoo has been caught behaving badly. This time, Yahoo was caught trespassing five different times via three different IPs over the course of four different days. Here is the data recorded in my site’s blackhole log (I know, that sounds terrible): Read more »
Okay, I realize that the title sounds a bit odd, but nowhere near as odd as my recent discovery of Slurp ignoring explicit robots.txt rules and digging around in my highly specialized bot trap, which I have lovingly dubbed “the blackhole”. What is up with that, Yahoo!? — does your Slurp spider obey robots.txt directives or not? I have never seen Google crawling around that side of town, neither has MSN nor even Ask ventured into the forbidden realms. Has anyone else experienced such unexpected behavior from one the four major search engines? Hmmm.. let’s dig a little further.. Here […] Read more »
Recently, while deliberating an optimal method for eliminating nofollow link attributes from Perishable Press, I collected, installed, tested and reviewed every WordPress no-nofollow/dofollow plugin that I could find. In this article, I present a concise, current, and comprehensive reference for WordPress no-nofollow and dofollow plugins. Every attempt has been made to provide accurate, useful, and complete information for each of the plugins represented below. Further, as this subject is a newfound interest of mine, it is my intention to keep this post updated with fresh information, so please bookmark it for future reference. Finally, please help expand/enhance this list by […] Read more »
During the most recent Perishable Press redesign, I noticed that several of my WordPress admin pages had been assigned significant levels of PageRank. Not good. After some investigation, I realized that my ancient robots.txt rules were insufficient in preventing Google from indexing various WordPress admin pages. Specifically, the following pages have been indexed and subsequently assigned PageRank: WP Admin Login Page WP Lost Password Page WP Registration Page WP Admin Dashboard Needless to say, it is important to stop WordPress from leaking PageRank to admin pages. Instead of wasting our hard-earned link-equity on non-ranking pages, let’s redirect it to more […] Read more »
Recently, I discussed the suspicious behavior recently observed by the Yahoo! Slurp crawler. As revealed by the site’s closely watched 404-error logs, Yahoo! had been requesting a series of nonexistent resources. Although a majority of the 404 errors were exclusive to the Slurp crawler, there were several instances of requests that were also coming from Google, Live, and even Ask. Initially, these distinct errors were misdiagnosed as existing URLs appended with various JavaScript functions. Here are a few typical examples of these frequently observed log entries: http://perishablepress.com/press/category/websites/feed/function.opendir http://perishablepress.com/press/category/websites/feed/function.array-rand http://perishablepress.com/press/category/websites/feed/function.mkdir http://perishablepress.com/press/category/websites/feed/ref.outcontrol Fortunately, an insightful reader named Bas pointed out that the […] Read more »
Jeff Starr (aka Perishable)
Perishable Press is the work of Jeff Starr, professional developer, designer, author, and publisher with over 10 years of experience. Check out some of Jeff's books and projects, follow on Twitter, or learn more »
Fun fact: Perishable Press has been online since 2005, and now features over 700 articles and more than 11,000 comments. More stats »