dbExpress Error: Invalid
Username/Password

Username/Password spelled correctly. The problem is because DBDesigner4 was designed for MySQL 3.x.x. For MySQL 4 and higher we have to do the old password trick. This is the solution which is works fine for me. In your terminal, connect to your database:

mysql -u root -p
SET PASSWORD FOR ‘root’@'localhost’ = OLD_PASSWORD(‘r00tp45sw0rd’);
UPDATE mysql.user SET Password = OLD_PASSWORD(‘r00tp45sw0rd’) WHERE Host = ‘localhost’ AND User = ‘root’;
FLUSH PRIVILEGES;

Then you should have no problem connecting to your MySQL servers. You may change the username (root), password (r00tp45sw0rd) & host (localhost) with your own.

1 – “We’ll figure this out later” (Lack of product goal and vision)

Sometimes a project starts, but not every detail is clear. That’s okay – the beauty of Scrum is its adaptability to uncertainties. However, as time progresses and core structures are being built, the lack of a clear vision becomes more and more of a problem. It’s not the problem of the team – it’s the problem of the product owner, whose responsibility is to define the product goal and vision in cooperation with the client and communicate it to the team. This can be a tedious process, especially if the client is unclear about his goals or has difficulty articulating them. A good product owner is able to assist the client and take the lead when necessary to come up with a product vision that is comprehensive, thought-through and makes clear to the team where the project is heading.

2 – “Everything is important!” (Lack of product priorities)

If product vision is lacking, prioritizing the product- and sprint-backlog becomes very tricky. If the product vision is clear, but there’s no agreement on which factors determine the business value for the client, prioritization is almost impossible. Priorities should be based on product vision and business value – if either is unknown, the product owner has not worked hard enough to sort this out. The consequence are backlog priorities based on what “feels right” rather than solid arguments, difficulties explaining backlog priorities to the team, as well as difficulties defending the backlog against questionable changes requested by the client. If client and PO agree on what the project is about right at the beginning, a lot of questions and conflicts that may arise later can be settled quickly by reiterating the goal and vision of the product.

3 – “I don’t care how you get there, just do it!” (Lack of clarity on development path)

Another consequence of lacking product goal, vision and/or priorities is that deciding on the best way of how to structure the development of a project becomes unnecessarily difficult. In other words: If the WHY and the WHERE are not clear, the HOW won’t be clear either. Here’s an example: There are three big features to be built – a forum, a chat, and a calendar widget. If they are seen as three separate and independent chunks of work, starting with either of them is okay. In the end, they have the same business value to the client. However, if the product vision is to create an online community that connects people with like-minded individuals around the world, the calendar should come last – because it promotes local connectes rather than global ones. In this case, a clear product vision helps prioritizing in a way that the business values might not be able to.

4 – “Who wrote this story?” (Lack of physical or intellectual presence)

Do you have your own office room? Maybe even on the top floor with a great view, far above the developer cubicles? Nice – but probably not very good for your project. Being physically and intellectually present and avaible to the team is crucial to keep product development on track throughout the sprint. If the PO is separated from the team, the risk increases that questions remain unanswered during the sprint, resulting in stories that the team considers “done”, but the PO doesn’t accept. The more availble the PO is during the sprint, the more precisely the outcome will match his and the client’s expectations. Also, by being confronted with the questions that the team has during a sprint, the PO can improve his specifications for the upcoming sprint and make sure future stories are more clear. For the same reason, the product owner must physically attend the sprint planning meeting and the review meeting – plus the retrospective and daily scrum meetings, if possible. That doesn’t mean he has to talk during all of them – but he should be there to listen, if nothing else. PO attendance at these meetings cannot be delegated to the scrum master or another team member.

5 – “Let me ask the client about this” (Lack of decision-making power)

Clients can be a pain: Some don’t know what they want and expect the PO to invent their product. Others who know what they want control every move and forget why they hired a PO in the first place. Having a product owner who is not given sufficient authority and autonomy by his client or CEO is almost as inefficient has not having a product owner at all: If the PO cannot make decisions when fundamental questions arise during the sprint, it is likely that someone within the team will start filling in and taking on the role of the product owner. The consequence is similar to what happens when a PO is not physically or intellectually present: stories are misunderstood, questions remain unclear, and results won’t match the expectations of client and PO. In another scenario, CEO or client are taking over the role of the PO and start micromanaging the project and its team. The result: The PO’s knowledge and understanding of the product remain underutilized, and his ability to relay the product vision to the team is corrupted. Furthermore, the quality of product management decreases, because neither CEO nor client are able to be as present as a PO should and could be.

Those of you who follow me on twitter, will know that me and my friends spends hours trying to install memcache on one of our web server. Normally this is a five minute job, but unfortunately for us those tricks did not work out.

So if you have tried YUM and APT-GET and still could not install the memcache then read on, to find the alternate( read manual, without magic ) way of doing it.

When we talk about Memcache their two things that needs to be installed

1. Memcache Daemon know as memcached, and
2. Memcache client for your programing language, in this case PHP.

Installing Memcache Daemon

Note these steps has been taken from http://in2.php.net/manual/en/memcache.installation.php

Steps to install Libevent(memcached dependency)

1. First we need to check if libevent is installed or not?
   1. type whereis libevent on shell.
2. If you don’t find it, then we need to download and install it.  Type following sequence of commands on your shell
   1. wget http://www.monkey.org/~provos/libevent-1.4.8-stable.tar.gz
   2. tar xfz libevent-1.4.8-stable.tar.gz
   3. cd libevent-1.4.8-stable
   4. ./configure
   5. make
   6. sudo make install
3. Finally we need to create a symlink to libevent
   1. type  sudo ln -s /usr/local/lib/libevent-1.4.so.2 /usr/lib on shell.

Now that we have installed the dependencies, we will install the memcahced.

Steps to install Memcached

1. Download and install, for that type following sequence of commands on your shell
   1. wget http://danga.com/memcached/dist/memcached-1.2.6.tar.gz
   2. tar xfz memcached-1.2.6.tar.gz
   3. cd memcached-1.2.6
   4. ./configure
   5. make
   6. sudo make install
2. Run Memcached as a daemon (d = daemon, m = memory, u = user, l = IP to listen to, p = port)
   1. type memcached -d -m 1024 -u root -l 127.0.0.1 -p 11211 on shell

Note: versions numbers mentioned here might be outdated, so do check for updated package to download.

Now we have installed and started the Memcache daemon, it’s time to install PHP client.

Installing Memcache Extension for PHP

Some of the steps mentioned below are taken from http://www.sitepoint.com/article/getting-started-with-pear/2/

1. Let’s determine the PHP version installed and also make sure it is in system path.
   1. type php -v on you shell, it should show something like PHP 5.2.6 (cli) (built: Nov  4 2008 09:25:57)
   2. type whereis php to get the path where PHP is installed in your system.
   3. In your accounts home directory create/edit ‘.profile’ file and add ‘export PATH=$PATH:/usr/local/bin‘ where ‘/usr/local/bin‘ is the folder where php executable is installed.
2. Install PEAR, type following sequence of commands on your shell
   1. wget http://pear.php.net/go-pear -O go-pear.php
   2. php go-pear.php and follow the installation instructions
   3. ls -l ~/.pearrc
   4. edit the ‘.profile‘ (again) and add export PATH=/home/yourname/pear/bin:$PATH
3. Finally Install Memcache
   1. type pecl install memcache on your shell, it will install memcahce extension for PHP.
4. Edit php.ini to add ‘extension=memcache.so‘, to find the exact php.ini file used by your system
   1. php -i | grep ‘php.ini’
5. Restart apache, and you are done  type one of the commands below to do that
   1. /etc/init.d/apache  restart , or
   2. service httpd restart

I hope this helps and save some time for you, I have a limited knowledge of Linux, so if some one can improve in the steps, please do so in the comments.

Suppose we were modeling the behavior of animals, by creating a class hierachy that started with a base class called Animal. Animals are capable of doing different things like flying, digging and walking, but there are some common operations as well like eating and sleeping. Some common operations are performed by all animals, but in a different way as well. When an operation is performed in a different way, it is a good candidate for an abstract method (forcing subclasses to provide a custom implementation). Let’s look at a very primitive Animal base class, which defines an abstract method for making a sound (such as a dog barking, a cow mooing, or a pig oinking).

public abstract Animal
{
   public void eat(Food food)
   {
        // do something with food....
   }

   public void sleep(int hours)
   {
        try
	{
		// 1000 milliseconds * 60 seconds * 60 minutes * hours
		Thread.sleep ( 1000 * 60 * 60 * hours);
	}
	catch (InterruptedException ie) { /* ignore */ }
   }

   public abstract void makeNoise();
}

Note that the abstract keyword is used to denote both an abstract method, and an abstract class. Now, any animal that wants to be instantiated (like a dog or cow) must implement the makeNoise method – otherwise it is impossible to create an instance of that class. Let’s look at a Dog and Cow subclass that extends the Animal class.

public Dog extends Animal
{
   public void makeNoise() { System.out.println ("Bark! Bark!"); }
}

public Cow extends Animal
{
   public void makeNoise() { System.out.println ("Moo! Moo!"); }
}

Now you may be wondering why not declare an abstract class as an interface, and have the Dog and Cow implement the interface. Sure you could – but you’d also need to implement the eat and sleep methods. By using abstract classes, you can inherit the implementation of other (non-abstract) methods. You can’t do that with interfaces – an interface cannot provide any method implementations.