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57

The short answer is "Because HTTP wasn't designed for it". Tim Berners-Lee did not design an efficient and extensible network protocol. His one design goal was simplicity. (The professor of my networking class in college said that he should have left the job to the professionals.) The problem that you outline is just one of the many problems with the ...


27

Why 410 gone? Since the page once existed the correct header status return would be 410 gone, this will inform Google and other search engines to drop the page from its index. You should avoid using status 400 bad request since this implies the server did not understand the request due to malformed syntax. Using undesirable status codes will populate your ...


14

Officially, yes. Any 4xx status may be interpreted as 400; the same goes for the other status groups. (E.g. a 503 service unavailable error may be interpreted as a 500 internal server error.) The RFC is written this way to allow for implementations that may not support every status, and also to allow additional status codes to be defined without breaking ...


13

According to the current version of the HTTP/1.1 standard, RFC 2616, the value of the Location header must be an absolute URI. However, in the draft standard prepared by the HTTPbis Working Group to eventually replace RFC 2616, this has been changed to allow relative URIs as well, apparently because: "The definition of the Location header [in RFC 2616] ...


11

Because they do not know what those resources are. The assets a web page requires are coded into the HTML. Only after a parser determines what those assets are can the y be requested by the user-agent. Additionally, once those assets are known, they need to be served individually so the proper headers (i.e. content-type) can be served so the user-agent ...


11

Your web browser doesn't know about the additional resources until it downloads the web page (HTML) from the server, which contains the links to those resources. You might be wondering, why doesn't the server just parse its own HTML and send all the additional resources to the web browser during the initial request for the web page? It's because the ...


10

Personally I would put domain.com on contact cards,etc and have it redirect to www.domain.com. This can be done with a simple rewrite. The reason for this is that my users should never be concerned with having to type www. I absolutely hate sites that require people to type the www - I think it's a completely outdated requirement from years gone by. You ...


10

TCP already has error correction, but this only helps you on the TCP layer. An intermediary HTTP proxy or load balancer can corrupt the data on the HTTP layer, and then retransmit it. A HTTP MD5 makes it possible to detect this corruption. The reason why nobody really talks about this need is that the problem is very rare indeed; most HTTP proxies etc "just ...


10

To complete the other answers, there is no authoritative database of complete IP -> name mappings. DNS provides for two kinds of mappings: name -> IP. Multiple names can map to a single IP IP -> name (aka "reverse"). A given IP can map only to a single name. Whether there is actually a reverse (IP -> name) mapping and what it points to is subject to the ...


9

There is more than Google in this world. A 410 unambiguously tells a bot that the file is gone. A 404 does not. A persistent bot might keep trying to find a 404 indefinitely whereas they might stop trying to find a 410 immediately which would make your server very happy.


9

According to RFC 2616 (HTTP/1.1), section 3.2.2, the URLs http://www.example.com and http://www.example.com/ are equivalent, and HTTP clients must normalize the former to the latter before sending the request to the server: "If the abs_path is not present in the URL, it MUST be given as "/" when used as a Request-URI for a resource (section 5.1.2)." ...


8

If your framework/CMS/whatever has the appropriate functions, you can include the scripting conditionally as @Michael suggests, but without the additional library. Taking your datatables case, for example, WordPress might handle the situation via something like: // For reference; this isn't functional code. if (is_page('whatever')) { <script ...


8

Web browsers do not care about canonical URLs. It is for search engine use only (specifically Google). Additionally, canonical URLs do not affect the loading or rendering of a web page. So no assets will be loaded over HTTP which is what would cause an insecure error message. So, no, they will not display any error message.


7

Because, in your example, web server would always send CSS and images regardless if the client already has them, thus greatly wasting bandwidth (and thus making the connection slower, instead of faster by reducing latency, which was presumably your intention). Note that CSS, JavaScript and image files are usually sent with very long expire times for exactly ...


7

Since 2014, Google has been giving websites available over HTTPS a slightly higher search engine ranking score. Given that your blog is only available over HTTP, it may appear lower in the results for some searches. However, Google isn't penalizing web site owners if other parts of their web sites aren't available over HTTPS but the main site is, at least as ...


7

Don't know if it's possible with simple command, but there are special "Reverse-IP" services just for that, check that one for example: http://viewdns.info/reverseip/ Apparently if you share IP with other domain, that is considered... malicious, like it's sending spam or spreading some viruses or having some "illegal" content, then your good domain also ...


6

You may want to look into <link rel="canonical" />. See http://googlewebmastercentral.blogspot.com/2009/02/specify-your-canonical.html. Down in the comments someone from Google says that it can be used for http/https issues. Caveat: I'm not sure if and to what extent <link rel="canonical" /> is supported by search engines other than Google, ...


6

From here It's Apache polling its child processes to verify they're responding correctly. 31-2 - 0/0/44 . 0.00 41 0 0.0 0.00 0.92 ::1 mxx1.xx.com OPTIONS * HTTP/1.0 The second field, " - ", shows that this isn't an active connection.. It's the last connection that took place for this particular thread/process. Since Apache polls ...


6

Regarding your second question: ::1 is localhost in ipv6. Regarding your third question: # Mark requests for the robots.txt file SetEnvIf Request_Method "^OPTIONS$" dontlog # Log what remains CustomLog logs/custom.log common env=!dontlog see also http://httpd.apache.org/docs/2.4/logs.html#accesslog


6

Can the server be reached in other ways than through HTTP or externally? Well... the server itself can be accessed by different means. Depending on what services are running on the machine (as well as what ports are open). Is GET and POST only populated through the HTTP protocol? Yes Is HTTP headers, GET and POST the only source of input for a ...


6

Your example URL, http://example/cat/http://example/dog, points to a page accessed with the http protocol, on the host example, with the path cat/http://example/dog. It's perfectly valid for the path part of a URL to contain elements that look like the protocol and hostname parts of another URL. One relatively prominent example of a legit site using such ...


6

Besides there being more search engines than Google out there, there's also no reason to assume that Google won't ever change the way they treat 410 responses. Indeed, it seems that's already happened: the information Matt Cutts quotes in the video is from 2007, whereas this post from 2009 by John Mu on Google's Webmaster Central forums says otherwise: ...


6

Section 14.30 of the HTTP 1.1 RFC http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.30 is not significantly different. I don't know that you're going to see any actual practical limitations for this. The only time I've seen even a warning about this issue is when I used to test in Lynx and the location was not absolute it would warn you "Location ...


6

You can use requirejs to dynamically load the libraries you need only on that pages. Then you only have to load the requirejs (which is about 14k) on all pages, saving about 385kb. Integration is also very easy: just "wrap" the code you have with the require include stuff: require(["jquery", "jquery.alpha", "jquery.beta"], function($) { //the ...


6

A user agent of Java/[version] is the default UA when making any web requests through the Java programming language. In other words, someone has written a spider-like program in Java, which is clearly parsing links incorrectly. As Dave suggested in the comments, the requests could be coming from another site - check the referring URL in your weblogs. In ...


6

See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9.3: The max-age directive on a response implies that the response is cacheable (i.e., "public") unless some other, more restrictive cache directive is also present. It's conceivable (likely?) that there are proxies in the wild which break this but since the only failure mode could be ...


6

HTTP2 is based on SPDY and does exactly what you suggest: At a high level, HTTP/2: is binary, instead of textual is fully multiplexed, instead of ordered and blocking can therefore use one connection for parallelism uses header compression to reduce overhead allows servers to “push” responses proactively into client caches More is ...


6

There doesn't seem to be a standard. The StackOverflow answer leans towards 410 GONE, but I think 301 MOVED PERMANENTLY is more appropriate. To make the correct choice, we have to look at your specific case. If your goal is to have all calls being made to API v1 fail without taking any further action, 410 GONE works for that. If you want some continuity, ...



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