Exam Prep 3 – Business Requirements

 This chapter was done in two parts + this post on another day. It was a big one, but not big enough to be done in three parts. However, I do want to give myself time when I need it, and this time I managed to get some quality Christmas feasts in there, and I was also trying some personal things. I’ll talk about them once they have evolved some more. Hopefully, they will do.

The title of this chapter is “Designing for Business Requirements”. In the beginning, it is explained that engineers usually are protected from talking to business colleagues by the architect. Which means the architect has to speak two languages. She has to understand the business use cases and the product strategy: the high-level objectives of the project. To be fair, I do think understanding what the product is trying to accomplish is important for the engineers as well, as they will be in a position to decide through the implementation, and they should be able to understand the implications of the different approaches.

The book gives some details about each of the use cases. I will not include them here, as they are incomplete, in the sense that the exam requirements have changed since the book was published. I do want however to write another post where I will try to understand the business requirements of each example exam project, and how they affect the technical decisions that need to be taken.

Application Design and Cost Considerations

In a business, cost should not be the main driver. In my opinion, the main driver should be the value it brings to its users. However, cost and finances are the enablers of the company. They do affect capital and operating expenses.

When developing a piece of software, the total cost of ownership (TCO) is not always evident in the beginning. There are a lot of hidden costs, that engineers like myself do not think about, but cloud architects should:

• software licensing costs
• cloud computing costs
• cloud storage costs
• data ingress & egress charges
• cost of DevOps personnel
• cost of third-party services
• missed SLA charges
• network connectivity charges

Managed Services

Managed services are a powerful set of features of GCP. They are offerings, whose operation is much less complicated and less expensive than maintaining virtual machines doing the same services, or even developing the same things in-house. These services are monitored automatically by Google, there’s no need for very low-level fine tunings (they usually autoscale), and the costs cannot be competed with.

Preemptible VMs

Preemptible VMs are virtual machines with limited running time, offered as an alternative to conventional virtual machines. They are much cheaper than virtual machines and are to be used with operations that do not require a single machine all through its lifecycle. Examples of this are batch jobs, services not requiring high availability, and stateless applications. They might be shut down at any time by GCP, and will surely be shut down after 24 hours, with a 30-second grace period. To replace them instantaneously, managed instance groups can be used. They can also be used with certain managed services.

Data Lifecycle Management

From what I have seen so far, data and databases and data management are a big part of this exam, and it’s one of the toughest, as GCP offers many data/storage services. You have to be very familiar with what each one is used for, so you can fine-tune your application in the cloud.

There are multiple categories for each storage option:

• Memorystore: for caching
• Databases: CloudSQL, Datastore
• Time-series databases, where the data will be aggregated over time (ex. today we want to see how the app behaves every hour, but in 1-2 weeks, we only care about the day as a whole)
• Object storage: multiregional and regional are used for frequently accessed data, nearline for data accessed once per month, coldline for data accessed once per year
• Data warehouse:
  • BigQuery has a 2-tiered pricing model:
    • active data (more expensive): updated in less than 90 days
    • long-term data (cheaper): not accessed in 90 days

System Integration and Data Management

In this chapter, the book went through all the exam projects and checked for what kind of data storage each should use. As homework for myself – besides checking each new project from the exam for high-level business requirements, I will look at the new projects and compare which storage solution should be better for which one. I also plan to do some research on what others think, if the time will let me.

Data Management Business Requirements

There are some things that the business colleague should be queried about when it comes to data management – ex. lifecycle policies and retention period:

• How much data will be collected and stored?
• How long will it be stored?
• What processing will be applied to the data?
• Who will have access to the data?

Compliance and Regulations

For most, GCP is already doing a lot to help the cloud apps stay secure. In many cases, it already encrypts data at rest. The user should still be aware of how to store protected data securely, IAM, firewalls, identity-aware proxy, the principle of least privilege, and defence in depth – which means assuming that things can break, and protecting every layer the best possible way.

Some policies that are mentioned in the book as well:

• Health Insurance Portability and Accountability Act (HIPAA)
• General Data Protection Regulation (GDPR)
• Sarbanes-Oxley (SOX)
• Children’s Online Privacy Protection Act (COPPA)
• Payment Card Industry Data Security Standard (PCI DSS)

Data Integrity Regulations

Vulnerability scanning and anti-malware applications should be in place. Protection against fraud should be cared about as well.

Security

• Confidentiality – limiting access
• Integrity – changing data should be allowed to the right entities only
• Availability – DDOS protection, redundant systems and failover mechanisms

Success Measures

KPIs and ROIs.

I also finished the quiz, 14/19. Which is not a bad score, but not good enough for me either. I made the mistake of writing down the wrong letter again. This mistake cost me 0.25 points once on my 12th-grade final computer science test – otherwise, it would have been a perfect 10. So besides putting more effort into data analytics on GCP, the additions to this exam since the book was published, I have to triple-check the letters I choose and write down. And I also have to take prettier notes so I can post some pictures together with my blog posts.