CompTIA Cloud+ Study Guide. Ben Piper
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      VPN Access

Schematic illustration of remote VPN access to a data center.

      Dedicated Private Connections

      Cloud providers offer connections to their data centers via private leased lines instead of the Internet. These connections offer dedicated bandwidth and predictable latency—something you can't get with Internet or VPN access. Dedicated private connections do not traverse the Internet, nor do they offer built-in encryption. Keep in mind that dedicated connections don't usually provide Internet access. For that, you'll need a separate Internet connection.

      Is My Data Safe? (Replication and Synchronization)

Schematic illustration of site-to-site replication of data.

      Applications such as databases have built-in replication processes that can be utilized based on your requirements. Also, many cloud service offerings can include data replication as a built-in feature or as a chargeable option.

Schematic illustration of synchronous replication. Schematic illustration of asynchronous replication.

      One common use case for asynchronous replication involves taking scheduled snapshots of VM storage volumes and storing those snapshots offline. The snapshots may also be replicated to a remote location for safekeeping. If you ever need to restore the VM, you can do so from the snapshot.

      Asynchronous replication can be more cost effective than implementing a synchronous replication offering. Cloud providers often charge for data transfer between regions or availability zones. Because asynchronous replication is not in real time, there's typically less data to transfer.

      Understanding Load Balancers

      Loose coupling (also called decoupling) is a design principle in which application components are broken up in such a way that they can run on different servers. With this approach, redundant application components can be deployed to achieve high availability and scalability.

      Let's take a look at a familiar example. Most database-backed web applications decouple the web component from the database so that they can run on separate servers. This makes it possible to run redundant web servers for scaling and high availability.

      But loose coupling introduces a new challenge: If there are multiple web servers that users can access, how do you distribute traffic among them? And what if one of the servers fails? The answer is load balancing. A load balancer accepts connections from users and distributes those connections to web servers, typically in a round-robin fashion. When a load balancer sits in front of web servers, users connect to an IP address of the load balancer instead of an IP address of one of the web servers.

Schematic illustration of load balancing web servers.

      Cloud Testing

      As you progress through this book, I will include information on the testing and validations that are required to ensure that changes and ongoing operations are valid and working as expected. In this chapter, you'll be introduced to three validations. Vulnerability and penetration tests are security-related, and I will expand my discussion of them throughout this book. You'll be introduced to load testing to ensure that your application works as expected when it is deployed into a heavily used production network.

      Vulnerability Testing

      Vulnerability testing is used to find objects in your cloud deployment that can be exploited or that СКАЧАТЬ