In the Hypertext Transfer Protocol (HTTP), HTTP header fields contain the operating parameters of an HTTP request or response. With the request or response line (first line of message), they form the message header.
4
votes
1answer
68 views
How do Expires headers and cache manifest rules work together?
I find the W3C's official Offline Web Applications specification to be rather vague about how the cache manifest interacts with headers such as ETag, Expires, or Pragma on cached assets. I know that ...
1
vote
1answer
51 views
How to configure apache2 to just save certain POST requests without even passing them to application?
I'm running Apache in front of glassfish server using BalancerMember.
For performance reasons I would like that POST requests on certain endpoint are just saved to a file without passing them to ...
1
vote
2answers
74 views
Is no cache meta tag bad for performance?
I see many websites, seemingly arbitrarily adding the no cache meta tag on every page.
Like this:
<META HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE">
<META HTTP-EQUIV="CACHE-CONTROL" ...
1
vote
3answers
312 views
302 Moved Temporarily or 301?
I have a question on redirects.
HTTP status code checker tool shows "HTTP/1.1 302 Moved Temporarily" for the home page URL http://someurl.com (just a namesake URL). Also, this URL opens up ...
7
votes
2answers
785 views
What are the Consequences for using Relative Location Headers?
According to the spec, Location headers used in a redirect require a server name
HTTP/1.1 301 Moved Permanently
...
Location: http://example.com/foo/baz/bar
However, in 2012, most web browsers will ...
1
vote
1answer
604 views
Google Chrome audit: resources are explicitly non-cacheable?
If I run a Google Chrome audit on a site, it lists all CSS, PNG, JPG, JS files and even the main domain (i.e. www.example.com) under the heading:
Leverage browser caching
The following resources ...
4
votes
1answer
74 views
HTTP Headers caching
I am not totally sure bout HTTP headers, but from what I read its good to have some level of caching on static pages also I am not sure if Transfer Encoding: chunked is a good thing. I was not finding ...
2
votes
1answer
79 views
What's the best HTTP code for dynamically deleted pages?
I've built my own CMS and I'm looking for the best way to handle pages / items deletion.
Actually, pages and items were deleted and cannot be restored.
But since I have implemented a bin, I don't ...
6
votes
1answer
107 views
Does the SPDY protocol eliminate the need for cookieless domains?
With plain HTTP, cookieless domains are an optimization to avoid unnecessarily sending cookie headers for page resources.
However, the SPDY protocol compresses HTTP headers and in some cases ...
2
votes
1answer
55 views
Why was 303 skipped in HTTP/1.0?
While looking back over HTTP response codes today I noticed that the 301, 302, and 304 response codes were defined in HTTP/1.0 but not the 303 response code. Does anyone know why the number 303 was ...
7
votes
3answers
937 views
Important fields in HTTP header from security perspective
What are the Important fields in HTTP header from security perspective? I tried to google it but unable to find. Can anybody provide me a link to read about it? Thanks in advance.
5
votes
3answers
293 views
What does it mean when a User-Agent has another User-Agent inside it?
Basically, sometimes the user-agent will have its normal user-agent displayed, then at the end it will have teh "User-Agent: " tag displayed, and right after it another user-agent is shown. Sometimes, ...
5
votes
3answers
394 views
How to tell the Browser the character encoding of a HTML website regardless of Server Content-Type Header?
I have a HTML page that correctly (the encoding of the physical on disk matches it) announces it's Content-Type:
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
...
0
votes
2answers
256 views
How to extract AdWords keywords from incoming traffic?
I have a landing page in which I need to understand what keywords are coming in from AdWords and then display some information based on this. I am not certain, but I don't believe that this ...
0
votes
0answers
66 views
Google crawler not found an error inside of the <head> tag
I've found a crawler error in my site and it is listed as a page not found(404) link.
Heres the broken link http://mydomain.com/blog/comments/feed/
I'm using Google web master tools and found that ...
4
votes
1answer
1k views
HTTP Header Cache Time: s-maxage and max-age
I am setting up a CDN for my website, I found the following sample for adding to the 'httpd.conf' file, this is used to adjust the cache-time for client and CDN:
ExpiresActive On
ExpiresByType ...
3
votes
3answers
145 views
PHP Include meta tags
A website I'm currently working on is http://www.troubi.com . Please don't care to look at the
source code.
If I validate the website through the w3cValidator a lot of errors occur all due to ...
7
votes
2answers
163 views
What should happen when content is deleted?
I am wondering about the standard handling of deleted data links from an application and an SEO perspective.
I have an application where users can create content but they can also delete content. ...
6
votes
1answer
6k views
Character set not specified in HTTP headers error
When testing this page with Page Speed, I get the a Specify a character set error:
The following resources have no character set specified in their HTTP headers. Specifying a character set in HTTP ...
2
votes
1answer
193 views
Sitemap file getting double compressed
I have a script that generates my XML sitemap and writes it to the file sitemap.xml.gz - i.e. an XML file, compressed with gzip. This file is definitely written correctly as when I download it via FTP ...
10
votes
1answer
1k views
What is recommended minimum object size for gzip performance benefits?
I'm working on improving page speed display times, and one of the methods is to gzip content from the webserver.
Google recommends:
Note that gzipping is only beneficial for larger resources. Due ...
7
votes
2answers
160 views
Does the 'Server' header serve any purpose?
For example, when I dump the response header for my server I get:
Server: Apache/2.2.11 (Ubuntu) PHP/5.2.6-3ubuntu4.5 with Suhosin-Patch mod_ssl/2.2.11 OpenSSL/0.9.8g
Is this used for anything? Is ...
4
votes
2answers
2k views
difference between accept and content-type http headers
So the accept header tells the server the mime-type of the resource the browser is looking for. For example, the server can send plain text, html, json, etc. Ok that makes sense. But then I look at ...
0
votes
1answer
505 views
What response headers encourage 304-Not Modified upon reloads?
When looking at the network waterfall in Firebug/Chrome/IE9, I keep seeing "200-OK" instead of "304-Not Modified" for many cache-able files (images, js, css) on this page, for example.
I believe it ...
3
votes
1answer
167 views
Use - or misuse - of ETags
I'm using an application that sets ETags by md5()ing the URL. As I understand it, that's quite insane. In effect, it means that content for a specific URL won't be fetched anew ... ever. Unless a ...
2
votes
2answers
567 views
How do I modify the HTTP headers?
Google page speed rank demands me to set an expiry date or a maximum age in the HTTP headers, by changing the "Expires" and "Cache-Control: max-age".
The site is hosted on a hosting company (not in ...
1
vote
1answer
112 views
Site structure changes possibly led to ranking losses
Problem
Last monday we changed our german only site from using wordpress to our own multi-lingual rails app. Since then our rankings dropped dramatically. I would like to know if the the recent ...
1
vote
0answers
100 views
wordpress header problem / cant add open graph tags [closed]
i am trying to add the facebook open graph tags to my wordpress site
woozybmx.com
i tried several options but everytime i add them the facebook lint returns something like the tags would be placed ...
2
votes
2answers
855 views
Should 304 Not Modified responses include the “Last Modified” header?
I've been using the most excellent http://redbot.org tool for testing have HTTP headers on my site correct (its custom code in PHP serving dynamic content - wanting to ensure it cached where possible ...
5
votes
1answer
6k views
Headers to prevent 304/If-modified-since/HEAD requests
What headers should I be sending to outright stop all requests to the server after the content has been cached?
We have a very high latency server (Sigh, VMWare) so even sending a HEAD request to the ...
5
votes
1answer
2k views
Can I set a variable “Expires” in Amazon S3?
I have a ton of files in Amazon S3 (served via Cloudfront) for which I have added an Expires header of Mon, Jan 1 2024 11:11:11 GMT
However, I have recently learned that setting an Expires header ...
3
votes
2answers
293 views
What's the best way to determine users' preferred language?
In determining which language to display content in by default, there are, as far as I know, three basic methods:
Examine the Accept headers sent by the browser.
Use IP geolocation to determine the ...
1
vote
1answer
178 views
Want to use the HTTP-REFERER of in an HTML page through Javascript
I Want to use the HTTP-REFERER of in an HTML page. Is it possible to do it with a JavaScript included in the page itself?
12
votes
1answer
229 views
What's the best way to end a Web site?
I have a Web site, built on ASP.NET MVC 3, that will be closing down completely. The domain will still be required for a few months, so during that time I'd like to display a single message on at ...
3
votes
1answer
118 views
Can server break clients' cache settings?
I have disputed a domain name to a cybersquatter that I expect to recover soon. The problem is that the cybersquatter has changed the cache headers and now every user who already visited the site or ...
1
vote
1answer
287 views
How to handle redirects & http status codes at urls where a product becomes unavailable?
I have this use case that happens frequently:
Lots of products for sale, periodically a percentage goes out of stock.
A user still browses in on the old url, to a location where a product used to ...
1
vote
2answers
182 views
“Cannot modify header information” error in my PHP/WordPress site
I edited the header.php and functions.php files in my WordPress site to add Google Analytics tracking code. Now, when I try to login to my admin area, the following warning appears and I am unable to ...
1
vote
2answers
165 views
Google Analytics when 404 handler is used as 'mod_rewrite'?
I'm consulting on a web site which in order to provide clean URL's uses the 404 handler to catch what would otherwise be a 404 and serve the correct content.
In case that's not clear the 404 handler ...
5
votes
2answers
44 views
What headers/META headers should I be using for an infinite link system like a calendar?
I have a web calendar, all my own work. It works fine. But I see in the logs a bunch of search indexers go round and round and round trying to chase every link. It could go forward to the year 3000 ...
2
votes
2answers
249 views
Using Pragma header on HTTP 1.1
would like know your opinion about using
Pragma header
when script is called in HTTP version 1.1
I don't know is good to return
both Pragma and Cache-Control
or rather return only Cache-Control
...
1
vote
2answers
67 views
Verifying that a user comes from a 'partner' site?
We're building a Drupal module that is going to be given to trusted 'corporate partners'. When a user clicks on a link, he should be redirected to our site as if he's a logged in user.
How should I ...
2
votes
1answer
90 views
Caching preventing users seeing site updates
I'm experiencing a caching issue I can't explain. This is happening across browsers, IPs and ISPs. If a user force-refreshes, they see the new content. If they then refresh or return to the page, the ...
1
vote
2answers
365 views
Temporary website redirect: 3xx or php/meta?
I run a (small) news website which has also a forum in a subfolder of the root. I'm planning to give the site a facelift and a code restructuration, so I wanted to put some redirect on the home page ...
3
votes
2answers
72 views
Browser privacy improvement implications for websites
On https://panopticlick.eff.org/ EFF let you test the number of uniquely identifying bits that the browser gives a website. Among these are HTTP header fields such as User-Agent, Accept, ...
2
votes
1answer
398 views
Problem with Expires/Cache-Control Headers
I'm using Apache 2.2.16.
I've got the following HTML file in my htdocs folder:
<html>
<link media="screen" type="text/css" href="/css/test.css" rel="stylesheet" />
...
1
vote
1answer
572 views
Enforcing a specific order for cookie headers
We have an application that cares about the order of cookie headers. It shouldn't, since this isn't mandated by the standards and indeed we're getting the headers in various different orders
So we ...
3
votes
2answers
129 views
HTTP response for deleted or disabled items on ecommerce store
What HTTP response should you send when an item/category on your ecommerce site has been disabled or deleted? 410 looks correct for deleted products but not sure about something that has been disabled ...
8
votes
2answers
1k views
When to use and not to use ETags
I was just looking at our site on WebPageTest.org and one of their recommendations for speeding up a website is:
ETag headers should generally not be used unless you have an explicit reason to ...
3
votes
1answer
856 views
What should my expires, cache-control, and pragma HTTP request header fields be set to?
I have a website in which I update the content approximately once monthly. When I check the HTTP request header fields, I get the following output:
Expires: Thu, 19 Nov 1981 08:52:00 GMT
...
2
votes
2answers
93 views
Why does the website heading on pubvantage.com display arbitrary text when it is listed in google search results?
the website www.pubvantage.com has a permanent redirect to http://exchange.contextweb.com/sellingdesk/pubvantage/.
The problem is, when a user enters the query +"pubvantage" in google, the site ...
