Controlling Search Engine Index Removals - search-engine

My site has some particular pages that are:
Already indexed in search engines, but I want to remove them from the indexes.
Numerous, as they are dynamic (based on query string).
A bit "heavy." (An overzealous bot can strain the server more than I'd like.)
Because of #2, I'm just going to let them slowly get removed naturally, but I need to settle on a plan.
I started out by doing the following:
Bots: Abort execution using user-agent detection in the application, and send a basically blank response. (I don't mind if some bots slip through and render the real page, but I'm just blocking some common ones.)
Bots: Throw a 403 (forbidden) response code.
All clients: Send "X-Robots-Tag: noindex" header.
All clients: Added rel="nofollow" to the links that lead to these pages.
Did not disallow bots to those pages in robots.txt. (I think it's only useful to disallow bots if you do so from the very beginning, or else after those pages are completely removed from search engines; otherwise, engines can't crawl/access those pages to discover/honor the noindex header, so they wouldn't remove them. I mention this because I think robots.txt might commonly be misunderstood, and it might get suggested as an inappropriate silver bullet.)
However, since then, I think some of those steps were either fairly useless toward my goal, or actually problematic.
I'm not sure if throwing a 403 to bots is a good idea. Do the search engines see that and completely disregard the X-Robots-Tag? Is it better to just let them respond 200?
I think rel="nofollow" only potentially affects target page rank, and doesn't affect crawling at all.
The rest of the plan seems okay (correct me if I'm wrong), but I'm not sure about the above bullets in the grand scheme.

I think this is a good plan:
Bots: Abort execution using user-agent detection in the application, and send a basically blank response. (I don't mind if some bots slip through and render the real page, but I'm just blocking some common ones.)
Bots: Send a 410 (Gone) response code."In general, sometimes webmasters get a little too caught up in the tiny little details and so if the page is gone, it's fine to serve a 404, if you know it's gone for real it's fine to serve a 410," - http://goo.gl/AwJdEz
All clients: Send "X-Robots-Tag: noindex" header. I think this would be extraneous for the known bots who got the 410, but it would cover unknown engines' bots.
All clients: Add rel="nofollow" to the links that lead to these pages. This probably isn't completely necessary, but it wouldn't hurt.
Do not disallow bots to those pages in robots.txt. (It's only useful to disallow bots if you do so from the very beginning, or else after those pages are completely removed from search engines; otherwise, engines can't crawl/access those pages to discover/honor the noindex header, so they wouldn't remove them. I mention this because I think robots.txt might commonly be misunderstood, and it might get suggested as an inappropriate silver bullet.)

Related

Avoid robots from going into a www.domain.com/thishash when link posted to twitter, facebook

I'm building a service where people gets notified (mails) when they follow a link with the format www.domain.com/this_is_a_hash. The people that use this server can share this link on different places like, twitter, tumblr, facebook and more...
The main problem I'm having is that as soon as the link is shared on any of this platforms a lot of request to the www.domain.com/this_is_a_hash are coming to my server. The problem with this is that each time one of this requests hits my server a notification is sent to the owner of the this_is_a_hash, and of course this is not what I want. I just want to get notifications when real people is going into this resource.
I found a very interesting article here that talks about the huge amount of request a server receives when posting to twitter...
So what I need is to avoid search engines to hit the "resource" url... the www.mydomain.com/this_is_a_hash
Any idea? I'm using rails 3.
Thanks!
If you don’t want these pages to be indexed by search engines, you could use a robots.txt to block these URLs.
User-agent: *
Disallow: /
(That would block all URLs for all user-agents. You may want to add a folder to block only those URLs inside of it. Or you could add the forbidden URLs dynamically as they get created, however, some bots might cache the robots.txt for some time so they might not recognize that a new URL should be blocked, too.)
It would, of course, only hold back those bots that are polite enough to follow the rules of your robots.txt.
If your users would copy&paste HTML, you could make use of the nofollow link relationship type:
cute cat
However, this would not be very effective, as even some of those search engines that support this link type still visit the pages.
Alternatively, you could require JavaScript to be able to click the link, but that’s not very elegant, of course.
But I assume they only copy&paste the plain URL, so this wouldn’t work anyway.
So the only chance you have is to decide if it’s a bot or a human after the link got clicked.
You could check for user-agents. You could analyze the behaviour on the page (e.g. how long it takes for the first click). Or, if it’s really important to you, you could force the users to enter a CAPTCHA to be able to see the page content at all. Of course you can never catch all bots with such methods.
You could use analytics on the pages, like Piwik. They try to differentiate users from bots, so that only users show up in the statistics. I’m sure most analytics tools provide an API that would allow sending out mails for each registered visit.

Url with pseudo anchors and duplicate content / SEO

I have a product page with options in select list (ex : color of the product etc...).
You accede to my product with different urls :
www.mysite.com/product_1.html
www.mysite.com/product_1.html#/color-green
If you accede with the url www.mysite.com/product_1.html#/color-green, the option green of the select list is automatically selected (with javascript).
If i link my product page with those urls, is there a risk of duplicate content ? Is it good for my seo ?
thx
You need to use canonical urls in order to let the search engines know that you are aware that the content seems duplicated.
Basically using a canonical url on your page www.mysite.com/product_1.html#/color-green to go to www.mysite.com/product_1.html tells the search engine that whenever they see www.mysite.com/product_1.html#/color-green they should not scan this page but rather scan the page www.mysite.com/product_1.html
This is the suggested method to overcome duplicate content of this type.
See these pages:
SEO advice: url canonicalization
A rel=canonical corner case
At one time I saw Google indexing the odd #ed URL and showing them in results, but it didn't last long. I think it also required that there was an on page link to the anchor.
Google does support the concept of the hashbang (#!) as a specific way to do indexable anchors and support AJAX, which implies an anchor without the bang (!) will no longer be considered for indexing.
Either way, Google is not stupid. The the basic use of the anchor is to move to a place on a page, i.e. it is the same page (duplicate content) but a different spot. So Google will expect a #ed URL to contain the same content. Why would they punish you for doing what the # is for?
And what is "the risk of duplicate content". Generally, the only onsite risk from duplicate content is Google may waste it's time crawling duplicate pages instead of focusing on other valuable pages. As Google will assume # is the same page it is more likely to not event try the #ed URL.
If you're worried, implement the canonical tag, but do it right. I've seen more issues from implementing it badly than the supposed issues they are there to solve.
Both answers above are correct. Google has said they ignore hashtags unless you use hash-bang format (#!) -- and that really only addresses a certain use case, so don't add it just because you think it will help.
Using the canonical link tag is the right thing to do.
One additional point about dupe content: it's less about the risk than about a missed opportunity. In cases where there are dupes, Google chooses one. If 10 sites link to your site using www.example.com and 10 more link using just example.com you'll get the :link goodness" benefit of only 10 links. The complete solution to this involves ensuring that when users and Google arrive at the "wrong" on, the server responds with an HTTP 301 status and redirects the user to the "right" one. This is known as domain canonicalization and is a good thing for many, many reasons. Use this in addition to the "canonical" link tag and other techniques.

Why do some websites have "#!" in the URL [duplicate]

I've just noticed that the long, convoluted Facebook URLs that we're used to now look like this:
http://www.facebook.com/example.profile#!/pages/Another-Page/123456789012345
As far as I can recall, earlier this year it was just a normal URL-fragment-like string (starting with #), without the exclamation mark. But now it's a shebang or hashbang (#!), which I've previously only seen in shell scripts and Perl scripts.
The new Twitter URLs now also feature the #! symbols. A Twitter profile URL, for example, now looks like this:
http://twitter.com/#!/BoltClock
Does #! now play some special role in URLs, like for a certain Ajax framework or something since the new Facebook and Twitter interfaces are now largely Ajaxified?
Would using this in my URLs benefit my Web application in any way?
This technique is now deprecated.
This used to tell Google how to index the page.
https://developers.google.com/webmasters/ajax-crawling/
This technique has mostly been supplanted by the ability to use the JavaScript History API that was introduced alongside HTML5. For a URL like www.example.com/ajax.html#!key=value, Google will check the URL www.example.com/ajax.html?_escaped_fragment_=key=value to fetch a non-AJAX version of the contents.
The octothorpe/number-sign/hashmark has a special significance in an URL, it normally identifies the name of a section of a document. The precise term is that the text following the hash is the anchor portion of an URL. If you use Wikipedia, you will see that most pages have a table of contents and you can jump to sections within the document with an anchor, such as:
https://en.wikipedia.org/wiki/Alan_Turing#Early_computers_and_the_Turing_test
https://en.wikipedia.org/wiki/Alan_Turing identifies the page and Early_computers_and_the_Turing_test is the anchor. The reason that Facebook and other Javascript-driven applications (like my own Wood & Stones) use anchors is that they want to make pages bookmarkable (as suggested by a comment on that answer) or support the back button without reloading the entire page from the server.
In order to support bookmarking and the back button, you need to change the URL. However, if you change the page portion (with something like window.location = 'http://raganwald.com';) to a different URL or without specifying an anchor, the browser will load the entire page from the URL. Try this in Firebug or Safari's Javascript console. Load http://minimal-github.gilesb.com/raganwald. Now in the Javascript console, type:
window.location = 'http://minimal-github.gilesb.com/raganwald';
You will see the page refresh from the server. Now type:
window.location = 'http://minimal-github.gilesb.com/raganwald#try_this';
Aha! No page refresh! Type:
window.location = 'http://minimal-github.gilesb.com/raganwald#and_this';
Still no refresh. Use the back button to see that these URLs are in the browser history. The browser notices that we are on the same page but just changing the anchor, so it doesn't reload. Thanks to this behaviour, we can have a single Javascript application that appears to the browser to be on one 'page' but to have many bookmarkable sections that respect the back button. The application must change the anchor when a user enters different 'states', and likewise if a user uses the back button or a bookmark or a link to load the application with an anchor included, the application must restore the appropriate state.
So there you have it: Anchors provide Javascript programmers with a mechanism for making bookmarkable, indexable, and back-button-friendly applications. This technique has a name: It is a Single Page Interface.
p.s. There is a fourth benefit to this technique: Loading page content through AJAX and then injecting it into the current DOM can be much faster than loading a new page. In addition to the speed increase, further tricks like loading certain portions in the background can be performed under the programmer's control.
p.p.s. Given all of that, the 'bang' or exclamation mark is a further hint to Google's web crawler that the exact same page can be loaded from the server at a slightly different URL. See Ajax Crawling. Another technique is to make each link point to a server-accessible URL and then use unobtrusive Javascript to change it into an SPI with an anchor.
Here's the key link again: The Single Page Interface Manifesto
First of all: I'm the author of the The Single Page Interface Manifesto cited by raganwald
As raganwald has explained very well, the most important aspect of the Single Page Interface (SPI) approach used in FaceBook and Twitter is the use of hash # in URLs
The character ! is added only for Google purposes, this notation is a Google "standard" for crawling web sites intensive on AJAX (in the extreme Single Page Interface web sites). When Google's crawler finds an URL with #! it knows that an alternative conventional URL exists providing the same page "state" but in this case on load time.
In spite of #! combination is very interesting for SEO, is only supported by Google (as far I know), with some JavaScript tricks you can build SPI web sites SEO compatible for any web crawler (Yahoo, Bing...).
The SPI Manifesto and demos do not use Google's format of ! in hashes, this notation could be easily added and SPI crawling could be even easier (UPDATE: now ! notation is used and remains compatible with other search engines).
Take a look to this tutorial, is an example of a simple ItsNat SPI site but you can pick some ideas for other frameworks, this example is SEO compatible for any web crawler.
The hard problem is to generate any (or selected) "AJAX page state" as plain HTML for SEO, in ItsNat is very easy and automatic, the same site is in the same time SPI or page based for SEO (or when JavaScript is disabled for accessibility). With other web frameworks you can ever follow the double site approach, one site is SPI based and another page based for SEO, for instance Twitter uses this "double site" technique.
I would be very careful if you are considering adopting this hashbang convention.
Once you hashbang, you can’t go back. This is probably the stickiest issue. Ben’s post put forward the point that when pushState is more widely adopted then we can leave hashbangs behind and return to traditional URLs. Well, fact is, you can’t. Earlier I stated that URLs are forever, they get indexed and archived and generally kept around. To add to that, cool URLs don’t change. We don’t want to disconnect ourselves from all the valuable links to our content. If you’ve implemented hashbang URLs at any point then want to change them without breaking links the only way you can do it is by running some JavaScript on the root document of your domain. Forever. It’s in no way temporary, you are stuck with it.
You really want to use pushState instead of hashbangs, because making your URLs ugly and possibly broken -- forever -- is a colossal and permanent downside to hashbangs.
To have a good follow-up about all this, Twitter - one of the pioneers of hashbang URL's and single-page-interface - admitted that the hashbang system was slow in the long run and that they have actually started reversing the decision and returning to old-school links.
Article about this is here.
I always assumed the ! just indicated that the hash fragment that followed corresponded to a URL, with ! taking the place of the site root or domain. It could be anything, in theory, but it seems the Google AJAX Crawling API likes it this way.
The hash, of course, just indicates that no real page reload is occurring, so yes, it’s for AJAX purposes. Edit: Raganwald does a lovely job explaining this in more detail.

What should i know about search engine crawling?

I don't mean SEO things. What should i know. Such as
Do engines run javascript?
Do they use cookies?
Will cookies carry across crawl sessions (say cookies from today and a craw next week or month).
Are selected JS filters not loaded for any reason? (Such as suspected ad which is ignored for optimization reasons?)
I don't want to accidental have all index page say some kind of error or warning msg like please turn on your cookie, browser not supported, or not be indexed because i did something silly such as having my sitemap point to /r?id=5 and not have then index because it is a redirect (i would use 301 however).
From here: http://www.google.com/support/webmasters/bin/answer.py?answer=35769
Use a text browser such as Lynx to examine your site, because most search engine spiders see your site much as Lynx would. If fancy features such as JavaScript, cookies, session IDs, frames, DHTML, or Flash keep you from seeing all of your site in a text browser, then search engine spiders may have trouble crawling your site.
Read Google's Webmaster guidelines

Can the Google Search appliance generate a report showing broken links on your site?

I know the Google Search Appliance has access to this information (as this factors into the PageRank Algorithm), but is there a way to export this information from the crawler appliance?
External tools won't work because a significant portion of the content is for a corporate intranet.
Might be something available on Google, but I have never checked. I usually use the link checker provided by W3C. The W3C one can also detect redirects which is useful if your server handles 404s by redirecting instead of returning a 404 status code.
You can use Google Webmaster Tools to view, among other things, broken links on your site.
This won't show you broken links to external sites though.
It seems that this is not possible. Under Status and Reports > Crawl Diagnostics there are
2 styles of report available: the directory drill-down 'Tree View'
and the 100 URLs at a time 'List View'. Some people have tried creating programs to page through the List View
but this seems to fail after a few thousand URLs.
My advice is to use your server logs instead.
Make sure that 404 and referrer URL logging are enabled on your web server,
since you will probably want to correct the page containing the broken link.
You could then use a log file analyser to generate a broken link report.
To create an effective, long-term way of monitoring your broken links, you may want to set up a cron job to do the following:
Use grep to extract lines containing 404 entries from the server log file.
Use sed to remove everything except requested URLs and referrer URLs from every line.
Use sort and uniq commands to remove duplicates from the list.
Output the result to a new file each time so that you can monitor changes over time.
A free tool called Xenu turned out the be the weapon of choice for this task. http://home.snafu.de/tilman/xenulink.html#Download
Why not just analyze your webserver logs and look for all the 404 pages? That makes far more sense and is much more reliable.
I know this is an old question but you can use the Export URLs feature on the GSA admin console then look for URLs with a state of not_found. This will show you all the URLs that the GSA has discovered but returned it a 404 when it attempted to crawl them.

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