Re: "Too Busy" Error Needed

Henrik Frystyk Nielsen (
Thu, 9 Jun 94 10:43:38 +0200

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>From Thu Jun 9 03:04:49 1994
Date: Thu, 9 Jun 1994 03:03:34 +0200

At 2:03 AM 6/9/94 +0200, Marc VanHeyningen wrote:
>> There are situations when an HTTP server may want to indicate that it is too
>> busy to accept a request. There is no code for this defined in the HTTP2
>> Taking the "spirit" of the 400 vs 500 errors, since this is a server
>> "problem", it seems like the 500 series is appropriate.
>Sounds reasonable.

This error message is also a good way to indicate when a proxy server is
unable to complete an FTP transaction because the remote FTP server has
reached its user limit. Currently this is reported as a 500 error.

For completeness sake, I would like to see this response added to the HTTP


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The reason for the 500 codes generated in the CERN Library as a result of a failed FTP session is to avoid having all kinds off error codes flying around in the HTTP response when connecting to a Proxy server. The same is the case in Gopher etc. etc.

Instead, the human readable messages from the various protocols are parsed using a nested error handling module, so that the user still can see why the session failed:

Requested URL:

Reply to user: WWW Alert: Fatal Error 500
Can't Access Document
Reason: FTP-server replies test: No such file or directory

Though, the top-level message is always a HTTP message.

BTW: Another code that I would like to get in is

502 Bad response

if the server response is wrong.


Henrik Frystyk
+ 41 22 767 8265
World-Wide Web Project,
CERN, CH-1211 Geneva 23,