How to choose server host in cloud computing era

In recent years, virtual space and shared space have begun to fade out of the webmaster's view, and more and more people are choosing to use separate hosts and virtual machines.

Standalone hosts have been around for a long time, and virtual machines have only slowly gained popularity in recent years.

Virtual machines are virtual hosts (such as Xen, KVM, VMware, Hyper-V, etc.) on a physical host (usually with a high hardware configuration, usually at least 8 core CPU + 32G memory start) A separate virtual operating system built on, with independent hardware resources such as CPU, memory, hard disk, etc.

Virtual machines are conceptually divided into two categories: VPS and cloud hosting.

VPS is well understood. Around 07 or 08, some IDCs began to use virtual technology to build virtual machines (VPS) on physical hosts for sale (originally mainly US VPS), many of which were exposed to VPS. Early people may know HyperVM, the VPS management panel, but before HyperVM, many small IDC service providers even used the command line and scripts to manually open and manage VPS. Later, there were some popular VPS management panels, the most used such as: SolusVM.

VPS has a lot of limitations for IDC service providers. For example, there are two parent machines, A and B. A remaining 5 G of memory, but the hard drive runs out; B has 500G of hard disk space left, but the memory runs out. At this time, you cannot use the memory on the A machine and the hard disk on the B machine to open a new VPS. For example, the memory and hard disk on the A machine have been used up, but there are 10 IP, and there is no IP on the B machine, but there is memory and hard disk. At this time, it is impossible to open the VPS on the B machine with the IP on the A machine.

The emergence of the cloud host completely solved the above flaws.

It should be emphasized that the cloud host is only a concept, not an industry technical standard. That is to say, no organization or organization has an authoritative definition for the cloud host, which specifies what elements or functions the cloud host must have. .

So what is the cloud?

The cloud I understand is the basic hardware and the virtual machines based on it, plus the complex software systems that manage these hardware and virtual machines. This management system is the focus of cloud computing, stable hardware, just like a strong body, and the management system is the soul of the cloud. Each cloud hosting service provider relies on this management system to implement a variety of different functions.

In my own opinion, the cloud host has at least two conditions relative to the traditional VPS: 1) Use an external storage device (such as a SAN) as the virtual machine's hard disk. 2) The IP address cannot be bound to a parent machine, but must be used on any parent machine.

When the cloud host has the above two conditions, the benefits are as follows: 1) The waste of resources is avoided (the problems that may occur in the VPS mentioned above do not occur on the cloud host). 2) Make the virtual machine more usable. For example, if a physical host has a hardware failure (no one can guarantee that the hardware will not be faulty), the cloud host on it can be automatically migrated to other physical hosts immediately. It only takes a few minutes, and the affected cloud hosts can Resurrection with full blood. The key to achieving fault migration is the prerequisites for the two cloud hosts I mentioned above. Failure to do so can not achieve fault migration. Alibaba Cloud's host has this fault migration feature, and I have encountered it once.

Moreover, the storage of cloud hosts generally has redundant design. Many webmasters have encountered data loss caused by hard disk failure when using virtual space and independent host. This occurs on the cloud host. The chances are much lower.

Disadvantages of cloud hosting: CPU and hard disk IO that directly affect virtual machine performance. These two are not completely independent resources on the cloud host. If the service provider does not design well on the underlying solution, then the cloud host The performance will be a problem. But in most cases, the performance requirements of the website or other applications are not very demanding, and all this problem does not have to worry too much.

Compared with the previous IDC industry, the difficulty and starting requirements for cloud hosting are much higher.

Originally selling virtual space, renting a separate server to install a management panel and financial system is OK.

Selling independent hosts, even if there is no requirement in the software, it is OK to make a difference directly from the computer room. If you order a little, you may rent the cabinet yourself, so you need more financial support, but in technology. There is still no difficulty on it.

Then the VPS can still start with one or a few independent hosts. The foreign SoluVM panel and the domestic XenSystem panel can be opened after the VPS is installed.

The software system for the hardware required by the cloud host is much more complicated. Although some open source systems, such as openstack, the difficulty of installing and using these systems and the management panel of the VPS mentioned above are completely out of one level, it only provides a low-level cloud computing framework, without considering some commercial ones. Things, want to be used to sell cloud hosts, secondary development is essential. There are more cloud hosting companies that choose to develop completely independently.

The starting requirements of the cloud host directly led to the fact that the entire industry will eventually have only a few unique ones, and the small IDC living environment is extremely hot. The cloud hosting service provider's incubation environment is roughly divided into the following categories: 1) Relying on the strength of the parent company to do cloud computing, such as: Alibaba Cloud, Tencent Cloud, Telecom Tianyi Cloud, 360 Cloud, Chuangyu Cloud, etc. It should be noted that some are really selling their lives in the cloud, while others are following the trend to play tickets, and must keep your eyes open. 2) After the initial formation of the technical team, it began to attract investment, such as: qingcloud.com (has received millions of financing), ustack.com (the amount of financing is unknown, has been engaged in software, no host products). 3) IT company technology executives entrepreneurial, such as ucloud.cn, this category is no shortage of technology and no shortage of funds, 4) traditional IDC is forced to adapt to the situation to develop cloud hosting.

How to distinguish cloud host and VPS? At its simplest point, VPS won't allow you to freely choose the hardware configuration. Its configuration and price will generally be a few fixed options, as explained above.

How to choose a cloud hosting service provider? If you directly recommend a home, it will inevitably become "soft text". To put it simply, if you have the strength (funding + technology) and are doing it seriously, then its products should not be inferior.

How to choose between independent host and cloud host?

Some cases where a separate host is required:

1) If the website program requires high hardware performance (such as wordpress) and is unwilling or unable to optimize, then basically only the hardware can be removed. Performance (such as E31230+32G+SSD RAID10).

2) Websites that consume a lot of traffic, typically such as: download station. The price of cloud hosting alone to increase bandwidth is relatively expensive.

If it is not the above two situations, then there is nothing wrong with choosing a cloud host, but you must choose the right service provider.