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I have never administered anything offering enough large downloads to warrant considering an implementation of a 'download manager'. That is, one of those java or .Net applications that manages a big download from something like Microsoft's MSDN sites.

As a user, I hate them, but do any admins run a site that uses one of these and can tell me what they get you as an administrator? Bandwidth savings perhaps?

Kyle Brandt
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2 Answers2

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The main thing is that when downloading a large file, some browsers do not resume after a timeout or other glitch interrupts the download. So for users with more dodgy or slower connections a download manager is vital. That being said, as long as you don't actively block them, the user can go and get something like Gozilla themselves.

Addn: more info on the akamai download manager

JamesRyan
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  • I can see that, but I have had MS downloads (akami powered it seemed) that the only way I could see to get the file was through the download manager since the links to Akami were just parts of the file. – Kyle Brandt Oct 27 '09 at 14:39
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    ah, that is so that it can simultaneously download from multiple parts of the akamai edge network

    http://www.akamai.com/html/technology/products/http_downloads.html

     – JamesRyan Oct 27 '09 at 14:47
  • EK: Except of course it kept crashing on the last couple of bytes :-P – Kyle Brandt Oct 27 '09 at 14:53
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(Note: The last time I was dealing with this topic was a couple years ago, so the latest browser versions may now work differently than I've described)

Another reason companies (particularly Microsoft) are doing this is because some downloaded files now exceed 2 gigs. For reference, 2 GB (2147483648 bytes) is the upper limit of a signed 32-bit integer. Most browsers, even the latest Firefox and IE, use a signed 32-bit integer to represent the size of a downloaded file. When the file size exceeds that number, all sorts of weird things start happening depending on which browser you use. Firefox, for example, seems to be able to finish downloading ok...but the progress window kind of goes crazy with the numbers it's displaying. Internet Explorer finishes immediately and you end up with an empty file. I don't recall what Opera or Safari do. In any case, the download managers are a way to ensure that the end users' computers can handle the large download sizes.

Ryan Bolger
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  • That makes sense! Although why would they not use unsigned? – Kyle Brandt Oct 27 '09 at 17:10
  • Either laziness on the part of the developer, or perhaps a negative number is used to indicate something (such as an error code). In any case, even if it was unsigned it won't be long before 4GB is hit. – Maximus Minimus Oct 27 '09 at 18:33