Huawei cloud computing ie interview notes – other knowledge points


*What is the difference between virtualization and cloud computing? What is the relationship between cloud computing and virtualization? What does Huawei cloud computing do?

Virtualization is a specific technology, which realizes the virtualization of hardware resources, improves resource utilization and reduces energy consumption. Cloud computing is a concept, a collection of various technical components, aiming at the management and scheduling of various resources, and facing the service level.

The virtual machine transforms the underlying hardware resources into a virtualization layer (generally referred to as hypervisor, which Huawei calls VMM).

cloud computing

Cloud computing is a computing mode, which realizes the pooling of resources, self-service and automation of services

Characteristics of cloud computing

1. On demand self service

2. Ubiquitous network access

3. Location independent resource pooling

4. Rapid elastic

5. Pay per user

The difference between cloud computing and virtualization

Virtualization is the foundation of cloud computing. The purpose of cloud computing is to realize resource pooling and service automation. To realize resource pooling, virtualization technology must be used.

There is also a bare metal architecture in the industry. Virtualization technology can not meet the requirements of high-performance applications, but the bare metal architecture can not support the whole cloud computing because it lacks flexibility.

The difference between openstack and virtualization.

Openstack is a cloud operating system, so its purpose is to shield the underlying differences and provide a unified and abstract interface upward. The underlying differences include those from virtualization. So in terms of architecture, openstack is above virtualization.

Explain IAAs, PAAS, SaaS

IAAs: infrastructure is a service, which refers to the provision of infrastructure to end users in the form of services. Including computing, storage, network and other computing resources, users can deploy and run any software, including operating systems and applications. For example: virtual machine rental, network disk, etc.

PAAS: platform as a service refers to providing the secondary development platform to end users in the form of services. Customers do not need to manage or control the underlying cloud computing infrastructure, but can control the deployed application development platform. For example: Microsoft’s Visual Studio development platform, salesforce, call center, etc.

SaaS: software as a service. The service provided to consumers is the application running on the cloud computing infrastructure. For example: enterprise office system.

Explain the public cloud, private cloud and hybrid cloud. Examples of public cloud are given for their respective application scenarios.

Private cloud: it is generally used by one organization and operated by this organization at the same time. Huawei data center belongs to this model. Huawei itself is the operator and its user, that is, the user and the operator are one, which is private cloud.

Public cloud: just like a shared switch, telecom operators operate the switch, but its users may be ordinary people. This is public cloud.

Hybrid cloud: it emphasizes that the infrastructure is composed of two or more clouds, but it presents a complete entity. During the normal operation of an enterprise, important data is saved in its own private cloud (such as financial data), and unimportant information is put into the public cloud. The combination of the two clouds forms a whole, which is a hybrid cloud. For example, the business volume of e-commerce websites is relatively stable at ordinary times. They buy servers to build private cloud operations, but when it comes to Christmas promotion, the business volume is very large. They rent servers from the public cloud of operators to share the high load of the festival; However, these resources can be uniformly scheduled, which constitutes a hybrid cloud.

Introduce block storage, file storage and object storage, and explain the differences?

Block storage takes blocks as the basic storage unit to provide storage space. Because it is the most original storage mode, it was designed in the form of hardware (such as hard disk) in the past. The design is simple without considering the locking mechanism. When multiple clients (processes and Applications) use the same piece of equipment, there is a risk of data damage. Therefore, it is not suitable (does not mean that it cannot be used) for multiple clients (processes and Applications). Features: not easy to share, good performance

File storage is to provide storage space with files as the basic unit. It usually works in the form of software on block storage. Therefore, it can easily design some mechanisms, such as the lock mechanism without block storage, so as to ensure that multiple clients (processes and Applications) can use the same file storage. (easy to share, poor performance)

Object storage is to provide storage space with object as the basic unit, and its core idea is to separate metadata from data. Using distributed technology, in the form of software, it usually provides storage space in the form of object on block storage or file storage. Compared with block storage and file storage, the main characteristics are linear expansion ability and network-based use (reflected in the fact that multiple hosts can share object storage space). Some object storage systems running on X86 even have the characteristics of low cost. The disadvantage of object storage is that it needs to consider the delay problem, or design a mechanism to reduce the delay, or require the application itself to be insensitive to the delay. (easy to share, excellent performance)