Using IIS6 on win2003, if I have an image server is it more efficient to serve up images as http than https? Also is it possible to serve up images as http on a webpage than is https.
Like if this html file: Secure.html is on a server that forces https to be used, but inside https://www.myultrahighsecurewebsite.com/Secure.html/
and I have a image like so:
<img src="http://www.notsosecureatall.com/imagecode/serveupanimage.aspx?id=1&auth=1" />
Is this a good way to serve up images? Is there a better way? Also I wanted to have a defacto site to serve up images so I don't have to push images as well as code and markup between development and live. Should the images or certain type of images like tiff, png, svg, etc... be on https vs http or does it matter?
If I do implement an image server or a page dedicated to keeping track of images, I just want an easy system to push images from development to my production environment without getting snagged on installation problems. But also not having to worry about customers having access to images until a version has been properly approved.
It will be more efficient from a CPU (client & server) and network point of view to use plain old HTTP. You'll avoid the overhead of TLS traffic and encryption/decryption of data.
The scenario (mixed HTTP/HTTPS) you present will often annoy a user though. You'll get a warning similar to "This page has unsecured content" (this is getting at the HTTP-only images).
See Loading http content on https website for more info (and additional gotchas) on the previous paragraph.
Are you sure that you need to worry about efficient loading of images? Don't overengineer this. Please share some more details if you've noticed that this is a problem.
Related
I have a web application that get a big amount of images via a server script proxy
which re-sizes them to specific thumbnails size.
so the url of a given image would be something like:
myDomain.com/scripts/myScript.php?url=anotherDomain.com/images/someImage.jpg&width=120&height=80
Due to some requirements I have to proxy these images this way, and I need to cache these images to ease the load on the server processing and re-sizing.
How do I go about configuring IIS7 to cache these urls?
I don't have in-depth knowledge of headers, so if needed, your elaboration will be very much appreciated.
thanks
click your site, click http Response headers, then click "set common headers", then expire web content and uncheck "immediately", then specify when you'd like it to expire.
Source
can I use CDN with images ? and if can then how to use it with upload from website to CDN server
Seems like there are a few options to accomplish this.
The first one would be using the CDN as Origin. In which case, there is already an answer with some advice.
The second option would be using your current website as Origin for the images. In which case you will need to do some DNS work that would look something like this:
Published URL -> CDN -> Public Origin
Step 1 - images.yoursite.com IN CNAME images.yoursite.com.edgesuite.net --- This entry will send all traffic requests for the images subdomain to Akamai's CDN edge network.
Step 2 - origin-images.yoursite.com IN A or IN CNAME Public front end for the images
So the way it works is that in step one you get a request for one of your images, which will be then sent via DNS to the edge network in the CDN (in this case Akamai HTTP only). If the CDN does not already have the image in cache or if its cache TTL is expired, it will then forward the request to the public origin you have setup to pull the file, apply any custom behavior rules (rewrites, cache controls override, etc), cache the content if marked as cacheable and then serve the file to the client.
There is a lot of customization that can be done when serving static content via CDN. The example above is very superficial and it is that way to easily illustrate the logic at a very high level.
Yes, and you can check with your CDN provider on the methods they allow for uploading,
such as
pull (CDN server download the files from your website/server)
or
push (sent from your website/server to the CDN server)
Example : automatic push to CDN deployment strategy
Do you mean you want to use a CDN to host images? And you want to upload images from your website to the CDN or use the website run by the company hosting the CDN to upload the images?
Ok, firstly yes you can use a CDN with images. In fact it's advised to do so.
Amazon CloudFront and RackspaceCloud's Cloudfiles are the two that immediately spring to mind. Cloudfiles you can upload either by their API or through their website and CloudFront you upload to Amazon's S3 storage which then hooks into the CloudFront CDN.
In common CDN setups you actually don't upload images to the CDN. Instead, you access your images via a CDN, quite like accessing resources via an online Proxy. The CDN, in turn, will cache your images according to your HTTP cache headers and make sure that subsequent calls for the same image will be returned from the closest CDN edge.
Some recommended CDNs - AWS CloudFront, Edgecast, MaxCDN, Akamai.
Specifically for images, you might want to take a look at Cloudinary, http://cloudinary.com (the company I work at). We do all of this for you - you upload images to Cloudinary, request Cloudinary for on-the-fly image transformations, and get the results delivered via Akamai's high-end CDN.
So I'm wondering how browsers treat requests for images. I'm hoping to use a cdn for serving product images on my website. I'd also like to use the cdn for serving button images and images used in my css.
The problem with this is that I don't have control over the expires headers (Rackspace files is what I'm looking into).
See, say I have a large image file as a background on my home page. So the page is accessed often, but the image stays the same. Is the browser going to request this image every time?
Or should I just use a cdn for my product images?
caching is quite a broad subject. I suggest you start by reading about the different kinds of caching here http://www.mnot.net/cache_docs/#BROWSER and how caching works here http://www.web-caching.com/mnot_tutorial/how.html
Now, to answer your question: assuming the user has caching enabled and the cdn response headers are properly configured a user visiting your page multiple times will only request that background image once until the cache expires or those files are cleaned.
No, AFAIK you need necessarily to add the 'cache' header to your images to enable browser caching. This is a great tutorial about it.
Additionally you can read this article from Yahoo to get a very brief view of the topics.
Review specially these topics of the article:
Minimize HTTP Requests
Add an Expires or a Cache-Control Header
Use a Content Delivery Network
Hope it helps you
I am a complete novice to Flash (never created anything in flash). I am quite familiar with web applications (J2EE based) and have a reasonable expertise in Javascript.
Here is my requirement.
I want the user to select (via an html form) an image. Normally in the post, this image would be sent to server and may be stored there to be served later. I do not want that. I want to store this image locally and then serve it via HTTP to the user.
So, the flow is:
1. Go to the "select image url":mywebsite.com/selectImage
Browse the image and select the image
This would transfer control locally to some code running on the client (Javascript or flash), which would then store the image locally at some place on the client machine.
Go to the "show image url": mywebsite.com/showImage
This would eventually result in some client code running on the browser that retrieves the image and renders it (without any server round trips.)
I considered the following options:
Use HTML5 local storage. Since I am a complete novice to flash, I looked into this. I found that it is fairly straightforward to store and retrieve images in javascript (only strings are allowed but I am hoping storing base64 encoded strings would work at least for small images). However, how do I serve the image via http url that points to my server without a server round trip? I saw the interesting article at http://hacks.mozilla.org/category/fileapi/ but that would work only in firefox and I need to work on all latest browsers (at least the ones supporting HTML5 local storage)
Use flash SharedObjects. OK, this would have been good - the only thing is I am not sure where to start. Snippets of actionscripts to do this are scattered everywhere but I do not know how to use those scripts in an actual html page:) I do not need to create any movies or anything - just need to store an image and serve it locally. If I go this route, I would also use it to store other "strings" locally. If you suggest this, please give me the exact steps (could be pointers to other web sites) on how to do this. I would like to avoid paying for any flash development environment software ideally:)
Thank you!
You could use a data URI to display the file. Essentially you use the image data (plus a prefix) as the src attribute of an image element. If you already figured out how to read the file into memory as a base64 encoded string, using a data URI would probably be the easiest way to display the image.
OK
I was able to implement the following solution (just in case anyone has any comments or would like to know the answer)
wrote server side code that takes an image and returns its base 64 encoded version.
used the hidden iframe trick to get the base 64 encoded data into an iframe and stored it into the image by dynamically changing the image source to the data uri
For the "hidden iframe trick" - in case you are interested, there is a good article at (see www.openjs.com/articles/ajax/ajax_file_upload/response_data.php)
The only limitation is that IE does not work with images whose base 64 encoded string exceeds 32K - see http://msdn.microsoft.com/en-us/ie/dd578309.aspx. Note that only IE 8 works - IE 7 does not support data uri I believe.
I'm designing a web application to support use of a CDN in the future.
Two options I've considered:
Use domain aliasing for static content on the site, including CSS, JS, and some images.
Use "edge side includes" to designate static content regions.
(1) is simpler and I've implemented it before. For example, we would prefix each IMG src with http://images1.mysite.com/, and then later update the corresponding DNS to use the CDN. The drawback I've heard from users of our internal "pre-production" site is that they would have to push the images to images1.mysite.com to preview their changes internally -- ideally, files would not get pushed to images1.mysite.com until they're ready for production. (NOTE - hosts file changes and DNS tricks are not an option here.)
Instead, they would like to simply use relative or absolute paths for static content. e.g. /images/myimage.gif
(2) is not as familiar to me and I would like more info. Would this allow our "pre-production" team to reference static content with a relative path in "pre-production environment" and yet have it work with the CDN in production without HTML modifications?
Could someone compare the two options, in terms of ease of development, flexibility, and cost?
Here's a variation on the second option to consider.
Leave relative image URLs alone in your HTML. On your production server, have image requests return a server-side redirect to the image location on the CDN. This generates marginally more traffic than the other techniques, but it generates an access log entry for each image hit, keeps your HTML and site structure simple, factors specific CDN dependencies out of your site source, and lets you enable, disable or switch CDN-based image service on the fly.
If you are using a demand-pulled CDN such as Coral, you also need to ensure that requests either issued by or declined by the CDN are served directly from your production server. See Using CoralCDN as a server operator for more information on this technique.