Update: Done! However, if the syntax highlighting looks a bit funny, that’s because I’ve used “php” for everything, since WordPress.com’s implementation of SyntaxHighlighter doesn’t seem to include bash/shell, rails, etc.

# apt-get install build-essential

On my machine, this installed:

The following NEW packages will be installed
  binutils build-essential cpp cpp-4.1 dpkg-dev g++ g++-4.1 gcc gcc-4.1 libssp0 libstdc++6-4.1-dev make patch

@event = Event.find(params[:id])
@comments = @event.comments.find(:all)

if @event.destroy && Comment.destroy(@comments)
  flash[:notice] = "Event deleted"
else
  flash[:error] = "There was a problem deleting the event"
end

redirect_to :action => 'index'

This worked fine, but changing the event model to:

has_many :comments, :dependent => :destroy

… means I can change the controller code to:

@event = Event.find(params[:id])

if @event.destroy
  flash[:notice] = "Event deleted"
else
  flash[:error] = "There was a problem deleting the event"
end

redirect_to :action => 'index'

On a side note, you have to do Comment.destroy(@comments) since this doesn’t work:

>> @event = Event.find(1)
=> #<event id: 1, name: "Fabric", location_id: 1, lineup: "Mark Farina<br />Terry Francis<br />Jon Marsh<br />James ...", date: "2005-04-23", url: "www.fabriclondon.com", tickets: "", price: "£15/£12 NUS", time: "N/A", user_id: 1>
>> @comments = @event.comments.find(:all)
=> []
>> @comments.destroy
NoMethodError: undefined method `destroy' for []:Array
        from (irb):3
>> Comment.destroy(@comments)
=> []
>>

The reason for doing code like:

+Client.first(:conditions => ["orders_count = ?", params[:orders]])+

instead of:

+Client.first(:conditions => "orders_count = #{params[:orders]}")+

is because of parameter safety. Putting the variable directly into the conditions string will pass the variable to the database as-is. This means that it will be an unescaped variable directly from a user who may have malicious intent. If you do this, you put your entire database at risk because once a user finds out he or she can exploit your database they can do just about anything to it. Never ever put your parameters directly inside the conditions string.

Awesome! I didn’t know that. These Rails Guides are SERIOUSLY awesome! Thank you to the guys involved w/ these!

https://bugzilla.redhat.com/show_bug.cgi?id=217141
https://bugzilla.redhat.com/show_bug.cgi?id=217630

We grabbed that file from the tomcat binary install tarball, dumped it into /var/lib/tomcat5/common/lib/, and that seemed to do the trick. However, we also had to upgrade java to 1.5/1.6 for whatever reason, so keep an eye on that also.

/usr/local/apache2/bin/apachectl start
/usr/local/bin/mongrel_rails cluster::start

The mongrel_rails cluster::start command failed due to missing configuration file, and a quick google search reveiled the command mongrel_cluster_ctl. As I understand it, mongrel_rails is to start an individual mongrel instance like so:

cd /path/to/application
/usr/local/bin/mongrel_rails cluster::start -C config/mongrel_cluster.yml

… while mongrel_cluster_ctl will start all the configurations symlinked in /etc/mongrel_cluster. Running like so did the trick:

/usr/local/bin/mongrel_cluster_ctl start

Wow, Passenger seems so much more straight-forward!

                                </ul>
                                </li>
                        <?php } ?>

                        <?php include( ABSPATH . 'google.inc'); ?>

                        <?php endif; ?>
                </ul>
        </div>

I’ll need to look into a plugin so that I don’t need to hack this each time I upgrade WordPress versions.

cpan> install M/MA/MARKSTOS/Data-FormValidator-4.57.tar.gz

(I found the previous version by looking at a CPAN mirror, but there probably is a CPAN command to search for previous versions also.)

# /etc/init.d/httpd stop
# gdb /usr/sbin/httpd
GNU gdb Red Hat Linux (6.5-37.el5_2.2rh)
Copyright (C) 2006 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "i386-redhat-linux-gnu"...
(no debugging symbols found)
Using host libthread_db library "/lib/libthread_db.so.1".

(gdb) run -X

At this point, go ahead and hit the site in an attempt to reproduce the segmentation fault. Once you’ve got a segmentation fault (it should return you to the (gdb) shell), run:

(gdb) backtrace

That should hopefully give you some indication as to where the segmentation fault is happening.

Update: You can also ‘bind’ to a running process by doing:

# gdb -p <pid>

mysql> SET GLOBAL max_connections = 150;

… and then modify /etc/my.cnf to make the change persistent.

The problem in doing this is that you’re not verifying that your /etc/my.cnf is correct and can only hope that a restart doesn’t encounter any problems.

Fortunately, Sai emailed us a great little tip to verify the syntax. You can run the following which will report errors in /etc/my.cnf:

# /usr/libexec/mysqld --help --verbose
081009  9:55:36 [ERROR] /usr/libexec/mysqld: unknown variable 'mmax_connections=150'

#

Perfect. Just what the doctor ordered.