Automatic upgrade

Vernon Schryver
Sun Nov 23 03:00:35 UTC 2003

> From: Aaron Paetznick <>

> The updatedcc program is currently not designed to do this, and I 
> wouldn't even try currently for reasons of common sense, but COULD 
> updatedcc eventually become something that could be run daily from cron? 
>   With the right precautions I would think this would be ideal to be 
> able to "push" out updates within minor version numbers.

What sort of precautions would be sufficient?  It's technically possible
to have FTP or HTTP servers that could tolerate 10,000 or even 100,000
system all asking about new versions at the stroke of midnight, but
it doesn't sound economically plausible.

I hope updatedcc will reduce the number of very ancient DCC installations
at least among DCC servers.  If it is safe to type
/var/dcc/libexec/updatedcc, maybe more people will do it more often.
I've thought of mentioning cron, but don't see how to make that work
(economically), just as I don't see how to make a desktop version of a
DCC client work.

A bi-monthly cron job at a distinctly unusual day and time would
probably be ok, but I don't know how to enforce that precaution.

The only practical precaution I can see is that if more than a very
few people did use a daily or weekly cron job, the current FTP
server would stop responding.

The 1.2.19 version of updatedcc is a little fancier.  You can tell it
to change ./configure parameters, environment variables, and FTP server.

That last is dangerous because of stale addresses.  Months ago I
removed my DCC server from the list to spare my
puny 128 kbit/sec bandwidth.  As far as I know, no current documentation,
DNS record, or similar advises using as a DCC server.
My DCC server rejects all anonymous DCC requests, but in the last
12 hours, more than 1400 systems tried.

Vernon Schryver

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