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New Breed Of Web Accelerators Actually Work
axlrosen writes "Web accelerators first came around years ago, and they didn't live up to the hype. Now TV commercials are advertising accelerators that speed up your dial-up connection by up to 5 times, they say. AOL and EarthLink throw them in for free; some ISPs charge a monthly fee. Tests by
PC World, PC Magazine and CNET show that they do speed up your surfing quite a bit. They work by using improved compression and caching. The downside is they don't help streaming video or audio." And they require non-Free software on the client's end, too.
Unfortunately, these caches store only the most accessed pages, so anything of any value to the Slashdot audience will be as slow as ever. But you can be sure your porn will be delivered at 5x the speed of your normal dial-up! (yawn)
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Why so many content providers aren't using gzip compression? The cpu time required is MUCH cheaper than the bandwidth, AND it makes users happiers because they get it faster. Oh, and it's free (for Apache anyway) and easy to set up. It even works with 99% of browsers these days.
And they require non-Free software on the client's end, too.
And I'll just bet that none of that software includes any popups, spyware or intrusive monitoring!
They actually work?
Next thing they find out is the new generation of penis enlargement devices actually work, too...
I don't need a signature.
Snake oil that works? What do you even call something like that?
My former company was checking out NetAccelerator recently to resell to our clients.
These things are a joke. The primary performance increase comes from recompressing images into really nasty JPEGs. AOL was doing this years ago (and getting blasted for it). If you turn that off, the performance improvement is not even measurable.
Furthermore, you tend to get a lot of stale caches on your machine. Most browsers don't even get this right, so they add yet another layer of potentially buggy cache abstraction.
No, these things are junk. They act as proxy servers and their source is closed. How can you trust them to handle your data? Even with all their compression features turned on, the performance improvement is seriously overrated. Don't bother. You simply cannot get something for nothing in cases like these.
Now, what would improve the download speed of the web is if web designers would start building standards compliant markup. Many web sites have as much as 700kb overhead in markup from tools that create loads of font tags and their ilk. Pure XHTML + CSS layout would do a hell of a lot more to speed up the web than these scams. Of course, don't take my word for it--read Zeldman.
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rproxy is a really interesting project, and back when I tried it over a 56K dial-up connection, it did actually work to speed things up. You sit an rproxy web cache at each end of the dial-up connection (so you need somewhere to deply your custom proxy to make it work, but bear with me...) and then request web pages as usual. Each end caches the pages that pass through it, but the clever part is that when you re-request a page, the proxy at the far end (on the fast connection) can fetch the page and compare with the last copy in the cache. Then it transmits only the differences using the rsync algorithm. Unforunately it's not being actively developed any more given the increasing availability of high-bandwidth connections, and the decreasing fraction of web traffic that is suitable for delta-compression. Shame, since it did seem to be a real "web accelerator" without any of the illusory techniques used by the garish banner-ad accelerators.
Matthew @ Bytemark Hosting
on
dialup.... ...
you....
insensitive
clod!
And my connection is wheezing just trying to post this!
mod_gzip is manna from heaven
I turned mine off by accident once and got a phone call from the co-lo wanting to know why I was suddenly maxing out.
gotta love that 70% saving.
There are places where the networks are not touching,and there are places where they are-Boeing's Lori Gunter
Nah, this is different altogether. Gzip is not the alpha and omega of compression.
Different algorithms lend themselves better to different applications, so it seems to me a good accelerator would use a mix of algorithms based on MIME type.
Ie; is the source data formatted in 24 byte words? 16 bit words? 8 bit words? If you have 8 bit data you don't want to look at 16 bit chunks, because then the string "abacadaeafag" doesnt compress for you. Dictionary sizes and blah blah blah... Even format conversion - turn all those BMPs that dingbats put on their pages into PNGs or lossless jpegs..
And as for caching, it seems to me like more of a prefetch than a squid-type cache.. Ie, you request page, proxy at IP gets page, compresses it on the fly, then sends it. Caching it locally is more of an advantage WRT latency, not throughput.
There's a lot of common sense tricks you could use. And according to these articles, they work.
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"Web accelerators"...You mean highly-advanced technology like mod-gzip?
Sounds pretty much like that... Which Apache already supports, and the major browsers already support, making something like this redundant.
Moreover, dialup modems already use a fairly high level of compression at the hardware layer. While not exactly "gzip -9" quality, you can only realistically squeeze another 10% out of those streams no matter how much CPU power you devote to the task.
Others have mentioned image recompression, which has traditionally used VERY poor implementations, nothing more than converting everything to a low quality JPEG. I would point out that a more intelligent approach to image compression could yield a 2-3x savings without noticeable loss of quality (smoothing undifferentiated backgrounds, stripping headers, drop the quality a tad (ie, to 75-85%, not the 20-40% AOL tried to pass off as acceptible), downgrading the subsampling on anything better than 2:2, etc). But no, not a 5x savings.
That's about all the article had to say:
Tests by PC World, PC Magazine and CNET show
These are the same magazines with full color, multi-page reviews of the new 0.025% faster hardware. They are the same magazines that review each micro$oft product and say that the TCO is lower than ever before. Take one look at any of their websites, and you will see:
These magazines are Advertisements
Taking anything from them seriously is like taking a presidential speech to be a serious economic discussion, or taking a realtor's web-site as gospel in the market.
Funny - just went to CNET.com to research my post, and guess what? Over 50% of the page is advertising. The rest is 'reviews' of which 100% have links to affiliate programs to purchase said hard/software and give a kickback to CNET.
They will try hard to sell anything, and get their commission. It's like they are the used car salesman of the internet - only everything is new and they don't look you in the eyes when lying to you.
Running Squid with a 256mb ram disk cache is all the speedup we need, and it does so without altering the data being fed from upstream.
"Only in their dreams can men truly be free 'twas always thus, and always thus will be."
--Tom Schulman
You......
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to the.....
William.....
Shatner....
school of.....
acting.....
didn't you?
why is it that downloading a 1meg file full of ZEROS still takes ages on a modem?
Because v.42bis has a maximum compression ratio of 4:1 (MNP5 only does 2:1).
Now, for a file of all zeros, hey, I agree, you can do a lot better. So, how often do you download files containing nothing but zero? For a typical text file, you might get better than 90% with gzip (while still only 75% from v.42bis). But from binary content? very rarely better than 50%.
In any case, web content consists of five basic types of information - Text, graphics, sound, multimedia (flash, MPEGs, AVIs, etc), and already-Zipped packages.
Of those, only the first benefits from any lossless method, and only the second really leaves any room for saving bits via lossy compression without horrible loss of quality at the same time. (Some of the fourth type could also possibly endure lossy compression, but takes far too long to recompress on-the-fly).
Unfortunately, text comprises the least bothersome (in terms of relative size) of all of those major types of web content.
Don't get me wrong, I fully encourage people to turn mod_gzip on in their Apache installs. But When a company hawks its product with claims that simply cannot occur in a normal webbrowsing situation, I have to call foul.
I see only two situations whereby they could claim 5:1 compression - Either VERY text-heavy material, such as reading something from Project Gutenberg, or they strip every possible non-critical image from a page. I already do the latter via my hosts file and a paranoid userContent.css, so what does that leave?
Hope you only like reading text, in which case, have you ever heard of "Gopher"?