[GLLUG] Perl Concurrent Transactions

[chuck@europa.affordablehost.com]

Question asked me today about how Perl on web servers handles concurrent 
transactions. 

I know my employer's web site writes temporary files so users have something 
to return to. It's an interesting technique but dates to 1996. It involves 
grabbing their IP address as a temporary file name. 

A quick look around the web today gave me these impressions: 

 - Perl 6 developers are working on this problem.
 - Modules like fastCGI or similar handle concurrent transactions.
 - Of course relational databases came up repeatedly. 

Only the last one, relational databases, I have to ignore. Perl hands the 
problem off to RDBMS. His question revolves only around Perl and flat data 
files. 

Submitting at the same millisecond may be rare but he's right our group has 
to face the problem. Any ideas or experiences here? 

Essentially the problem is two users trying to update a data file at the 
same time. 

thanks,
chuck williams