# Use a stack to keep track of concurrent connections
my @connections;

while (<MERLOG>) {
  # Assume that seeing "Connection" before seeing "QUIT"
  # implies an interleaved connection record.
  if (/^Connection/) {
    ++$count_of_connections;
    push (@connections, $_);
    ++$count_of_overlaps if (scalar(@connections) > 1);
  }
  pop (@connections) if /^QUIT/
}

print "$count_of_connections connections logged, $count_of_overlaps overlapped\n";
print "Leaving ", $count_of_connections - $count_of_overlapped, " clean connections logged.\n"