Cloud era: differences between Vm instances, virtual hosts, and VPS

ArticleDirectory

• 1. Virtual Hosts, VPs, and cloud hosts
• Ii. Differences between virtual hosts, VPs, and cloud hosts
• Iii. Advantages of cloud hosts
• Iv. disadvantages of VM instances

In the cloud computing era, the scalability, low price, and secure and reliable features of VM instances are well received by enterprises and developers. However, some IDC enterprises are currently using old wine in a new bottle, package virtual hosts and VPS to launch the so-called cloud host service. To help users better identify and select cloud hosts, the following describes the features and differences of virtual hosts, VPs, and cloud host products.

1. Virtual Hosts, VPs, and cloud hosts

Shared hosts are also known as virtual hosts. Since the birth of the Internet, most Webmasters have learned how to build websites from shared hosts. The so-called "shared host" means that a server has many websites, and everyone shares the hardware and bandwidth of this server. If it fails, all the above websites will be inaccessible.

A virtual private server (VPs) is a high-quality service that divides a server into multiple virtual private servers. Each VPs can be assigned an independent public IP address, an independent operating system, an independent ultra-large space, independent memory, independent CPU resources, and independent execution.ProgramAnd independent system configuration. In addition to multiple virtual hosts and unlimited enterprise mailboxes, you can also have independent server functions. you can install programs and restart the servers separately.

Cloud hosting can be regarded as a new generation of shared hosts.

First, the host company makes its hardware and network lines into a "Cloud", and then provides some network interface APIs to this "Cloud" for customers to use. At this time, each customer no longer shares a specific server, but all servers in the cloud.

For example, if you want to back up local files to the Internet, you can use a shared host to upload files to a server. You can also use a cloud host to use some form of interfaces, upload them to the cloud. That is to say, shared host users directly face specific servers, while VM instances directly face network interfaces and cannot see the server.

A common analogy is that you can rent a safe deposit box (shared host) numbered "8888" to a bank, or you can send valuables directly to the Custodian company for safekeeping.

Products such as Gmail, Facebook, Twitter, and Flickr can all be seen as "cloud host-based" services.

VM instances have the root permission. Users can reinstall and upgrade the operating system. However, VPs host users do not have the root permission and cannot reinstall or upgrade the operating system.

Ii. Differences between virtual hosts, VPs, and cloud hosts

(1) Supply and deployment time

Virtual Host-days to weeks
VPs --- real-time, no need to install the Operating System
Cloud host-real-time, just a few minutes to complete, one-click deployment, or independent installation of the Operating System

(2) security and reliability

Virtual Host-General: high failure rate, basic no ARP, Trojan and DDOS defense capabilities, basic no backup machine and Data Backup Service
VPs --- poor: program defects, ARP spoofing, viruses, and resource occupation installed on other VPs on the same physical server will seriously affect itself; basically no ARP, Trojan, and DDoS Defense Capabilities
Cloud host-high: built-in ARP defense, scale-up to improve anti-DDoS capabilities; Share the performance and reliability of brand enterprise-level servers and hardware virtualization, built-in ha; provides a variety of quick recovery measures, such as backup machines, snapshots, and data backups.

(3) performance and assurance

Virtual Host-good and guaranteed
VPs --- poor
Cloud host-good and guaranteed: Same as physical server

(4) elasticity and scalability

Virtual Host-new servers need to be rented again for expansion and the original resources need to be paid
VPS-fast resizing, subject to the configuration of a single server
Cloud host-real-time supply, on-demand scaling, no need to pay for original rental Resources

(5) cost of ownership

Virtual Host-the service provider needs to pay a deposit for the pay-as-you-go service on a yearly basis, and the service provider needs to pay a deposit for the pay-as-you-go service provider; the servers that need to be maintained and rented by themselves lead to a high OPEX
VPS-low-configuration VPs rental prices are the lowest; however, low security and reliability and unguaranteed performance result in unguaranteed service quality, difficult to control and high operating costs
Cloud host-lowest overall cost: no monthly deposit, pay-as-you-go for on-demand usage, and basic Zero maintenance. You can also share the cost advantages of scale, green energy saving, and Best IT practices.

(6) ease of use and easy management

Virtual Host-Remote Control card is required and only brand-name machines can be rented. centralized and unified management cannot be implemented.
VPS-provides a single-host management interface without the root or super administrator operating system permissions. The management flexibility is subject to the management interface.
VM instances-with built-in KVM, the customer can centrally manage VM instances distributed in different regions through the self-service system. They have full root or super administrator operating system permissions.

Iii. Advantages of cloud hosts

(1) cheap.

Because services can be distributed across multiple servers, resources can be fully utilized, reducing hardware, power, and maintenance costs. In addition, Vm instances are billed based on usage, with more and less, which is especially beneficial to small websites.

(2) reliable.

Because services are distributed across multiple servers or even multiple data centers, it is not easy to go down completely. The disaster tolerance and fault tolerance capabilities are strong, and the service can be online for a long time.

(3) scalability ).

The basic feature of VM instances is the distributed architecture. Therefore, you can easily add servers and multiply the service capabilities.

Iv. disadvantages of VM instances

Some customers are worried about the security of VM instances and feel lack of control over services.

Because VM instances only provide network interfaces, all customer data must comply with the arrangement of the cloud service company and be completely under the control of the latter. Whether the data is secure and confidential depends on the latter's professional ethics and protection capabilities.

However, this is actually a "pseudo problem", because in most cases, cloud service companies are more concerned about and better at protecting data than customers. Paul Graham talked about this in hacking and painter:
Opponents often think that our products are insecure. If employees can log on easily, the bad guys can log on easily. Some large companies do not think they can give us customers' credit card information, but put them on their own servers for better security ....... But in fact, their servers are not secure, and our data protection is almost certainly better than ours.

Think about it. Who can hire a higher level of network security experts? is a technology-based startup company that manages servers or a clothing retailer ?...... We are more concerned about data security than they are. If the server of a clothing retailer is infiltrated and affects the company at most, it is likely to be covered up inside the company, in the worst case, an employee may be dismissed. However, if our servers are infiltrated, thousands of companies may be affected. This may also be regarded as news and published on Industry websites, making our business unable to continue, I had to close my business.

If you want to hide your money in a safe place, do you choose a mattress in your home or a bank? This metaphor applies to all aspects of server management, not only for security, but also for normal running time, bandwidth, load management, backup, and so on ."

Reprinted from: http://www.chinaz.com/prime/2012/1021/279069.shtml