Every month or two a swarm of robot visits my site on a managed server and opens up connections so fast that my current max_user_connection value of 25 (will increase it to 75) is reached. Currently I restart the server and it works fine again until the next swarm comes. It is a webshop programmed in perl which tries to get the data using DBI connect, like this : 
  $db=DBI->connect('dbi:mysql:******');
  $query = $db->prepare("SELECT * FROM `Tablename` WHERE 1 AND `artnr`
+ = '$link' ORDER BY id DESC LIMIT 0 , 25;");
  $query->execute();
  
  while (my @row = $query->fetchrow_array()){      
  (datas like name etc,*,*) = @row;  
  print "Shoppage"  
  }
  
  $query->finish;
  $db->disconnect();

[download]
There are some more connections in the same script looking for a cart and an whitelist name. So I have some questions : Will the problem solve itself after some time or will the open process run until reset and try to get infos from the locked DB ? Is it possible to do a small query to check for max user connections on the DB to exit if it is to high ? Any other idea to get protection from DOS attacks or bot swarms (thought about rectriciting Asian IPs in htaccess or using HTTP::BrowserDetect) ? Thanks for you time any maybe Help !

In reply to Optimize DBI connect to avoid max_user_connections by Alex-WisdomSeeker

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