第13章ハイブリッドマルチクラウドのデジタルソリューション開発

By the end of this section, you will be able to:

• Learn how to use IaaS storage services

• Learn how to use IaaS compute services

• Understand IaaS support services for web and mobile applications

• Relate to IaaS container management services

• Understand IaaS support services for database management

From a business model perspective, start-ups and companies with fluctuating workloads depend on finding a way to effectively deploy and manage their applications. This includes considerations such as cheap, reliable performances that can adapt to unpredictable seasonal demands. This calls for a service model that allows businesses to access cloud resources and adopt agile infrastructures without having to worry about IT management.

One solution to such demand is infrastructure as a service (IaaS). IaaS offers on-demand access to cloud computing services, provides a pay-as-you-go pricing model, and allows the user to take advantage of cloud servers by virtually managing data and servers for their application. IaaS allows the engineering team to optimize the platform from the infrastructure and does not get locked into any cloud provider’s settings.

In this section, we will delve deeper into the different layers of operations that IaaS provides. As the infrastructure is provided without any special setup, IaaS, as a framework, requires additional skills and time from the engineering team to set up and maintain their platform. Throughout these sections, we will go through different common infrastructures that mainstream IaaS providers usually accommodate so that we can determine the best approach to maintain our cloud applications.

A storage service is one of the base infrastructure components that a cloud provider would provide that allow the user and the application to read, write, and access storage. These services are elastic storage services, and the word elastic is used throughout the chapter to indicate an unlimited number of resources that the user can access from the cloud provider. Some common components in the application that may require storage access are analytical data, logging information, application data, images, and videos. The storage required for these components may grow over time as the application operates, so the users must understand the type of storage service that they choose for their application. It is also common that the user may choose more than one service to use in their application. There are several types of storage services that the user can choose from, depending on the cloud provider. For example, Microsoft Azure allows users to create a storage account that makes it possible for them to use blob storage as explained in the following paragraph, mount Azure-based remote file systems to their local machine, create column-oriented database tables, or create a queue to receive streaming data from a sensor. However, there are three common types of services that all cloud providers provide:

• The first, file storage, manages data as files. This is the most common storage service among first-time users as it is the easiest concept to understand. Most users who use computers daily are familiar with File and the way it stores in their local environment. However, as File has a tendency to grow in size and its format can get complicated, the File storage becomes more difficult to manage as the application operates and grows in the Cloud Environment. The structure of the file system can also be carried into each File being stored in this service. Some common file metadata that are managed and tracked by the Cloud Provider are file name, file size, timestamp, and permissions.

• The second, object storage (or blob storage), manages data as blobs, with each blob representing any data format, such as a file in a local filesystem. A blob can contain any type of data, such as a small value, a document, an image, a video, or a collection of such. Cloud providers allow access to the information stored and its associated metadata via an API/SDK or via direct web links in the case of pictures for example. Common metadata includes name, size, timestamp, and custom-tag. In some cases, this approach helps manage the storage of items and also makes them available to anyone who is given access to them in the cloud, which is not possible when storing data items in a local file system. This service is commonly used by consumer applications and allows them to access and retrieve data items as objects using their names and tags.

• The third, block storage, manages the data as blocks or physical range of storage in the physical device (such as a hard disk drive [HDD] or Non-Volatile Memory Express [NVMe]). Each block address can range from a few kilobytes or several megabytes in size. Because this service can provide a way for the user to directly access the data using a physical address, it does not need to manage the entire set of data objects. The most common usage for this service would be a system application such as an operating system or database where they need access to files much quicker, and they can keep track of and manage how the data are changed.

To access the storage services from the application, the developer would have more than one way to access the data. Figure 13.2 shows a simple view of different access patterns on how the user and application can get access to the storage service.

Most cloud providers will provide different tools to support different environments that the user may use to access their infrastructure and services. The storage service will usually be provided as a location in the cloud for the user to access. If the user is a developer, they can access the storage directly through their code using a software development kit (SDK), which is used to access the storage needed to read, write, and store data. This kit is usually provided by the cloud provider and works with different programming languages. Some applications running on the cloud environment also use this SDK to write operational data, such as logs, or consume different configurations that were stored in the cloud environment. If a user is a cloud administrator, they can also access the storage service through a computer terminal using command line interface (CLI). This is also a tool provided by the cloud provider, and this tool will allow users to access the storage service and manage their data. Finally, the user can also access the storage service through the web interface console through their browser. By doing it this way, the user can access their data interactively through their browser. Generally, cloud resources are available either via a cloud portal interface, an SDK that is accessed programmatically, or a CLI that enables users to invoke SDK constructs on the command line. Figure 13.3 shows the web interface for an Azure storage account container (aka, blob) accessible via the Azure object storage service’s web console. On the Amazon AWS cloud, blobs can be created as buckets within the Simple Storage Solution (S3).

Another important component in the cloud storage service is the storage access point. The access point is one of the critical components in cloud architecture that will minimize the latency that the user can consume the data. Based on the user’s location, the cloud provider can provide the available access point closest to the user’s location to eliminate long I/O latency. However, this is also one of the key problems of leveraging storage service when the application is scaled out. Depending on the cloud provider, there are a fixed number of access points in an area for each account to consume. Usually, it would not be an issue for a small- or medium-performance application. However, for real-time and high-performance applications, this restriction may become a bottleneck for the application to operate correctly. This issue can be resolved when the user moves to a hybrid cloud solution where they can spend a bit more up front to pay for backing up data devices and hardware that can be located in their local area.