PrintNumber	ErrorLocation	Error	Correction	DateAdded
1	piv	First Printing: May 2011	TBD	8/1/2011
1	p103	Rule 24: What, When, How, and Why What: Alleviate temporal constraints in your system whenever possible. When to use: Any time you are considering adding a constraint that an item or object maintains a certain state between a user’s actions. How to use: Relax constraints in the business rules. Why: The difficulty in scaling systems with temporal constraints is significant because of the ACID properties (see definition in Chapter 2, “Distribute Your Work”) of most RDBMSs (Relational Database Management Systems). Key takeaways: Carefully consider the need for constraints such as items being available from the time a user views it until they purchase. Some possible edge cases where users are disappointed are much easier to compensate for than not being able to scale.	Rule 24: What, When, How, and Why What: Make use of application caching to scale cost effectively. When to use: Whenever there is a need to improve scalability and reduce costs. How to use: Maximize the impact of application caching by analyzing how to split the architecture first. Why: Application caching provides the ability to scale cost effectively, but should be complmentary to the architecture of the system. Key takeaways: Consider how to split the application by Y Axis—Rule 8 or Z Axis—Rule 9 before applying application caching in order to maximize the effectiveness from both cost and scalability perspectives.	8/1/2011
1	p229	Rule 24—Utilize Application Caches What: Alleviate temporal constraints in your system whenever possible. When to use: Anytime you are considering adding a constraint that an item or object maintains a certain state between a user’s actions. How to use: Relax constraints in the business rules. Why: The difficulty in scaling systems with temporal constraints is significant because of the ACID properties of most RDMSs. Risk reduction: M Cost: M Benefit and priority: Medium - 3 Key takeaways: Carefully consider the need for constraints such as items being available from the time a user views it until the user purchases it. Some possible edge cases where users are disappointed are much easier to compensate for than not being able to scale.»	Rule 24—Utilize Application Caches What: Make use of application caching to scale cost effectively. When to use: Whenever there is a need to improve scalability and reduce costs. How to use: Maximize the impact of application caching by analyzing how to split the architecture first. Why: Application caching provides the ability to scale cost effectively, but should be complmentary to the architecture of the system. Risk reduction: M Cost: M Benefit and priority: Medium - 3 Key takeaways: Consider how to split the application by Y Axis—Rule 8 or Z Axis—Rule 9 before applying application caching in order to maximize the effectiveness from both cost and scalability perspectives.	8/2/2011