At present, cloud computing, cloud storage, cloud backup and other technologies can be described as overwhelming, and many of them are fishing in troubled waters. Originally, there is not much cloud nature, but they are just hyped under the banner of cloud.
At present, the market has no clear definition of whether a product is a cloud. Because the cloud does not have a standard.
how did the cloud come aboutWhen referring to a bunch of equipment in foreign countries, the word Cluster is generally used, and the Chinese translation is generally "cluster" or "cluster". The origin of the word cloud can no longer be tested. Maybe someone said "The Servers in the cloud" when he was teaching PPT, so the word Cloud was born.
Several Understandings of Cloud
At present, people's understanding of cloud basically has four different viewpoints: cloud is device, cloud is cluster, cloud is IT system, cloud is service
The cloud is the device:
This is the most primitive view, that is, the so-called cloud just refers to a bunch of devices, because without the support of the device, where can the cloud come from.
Cloud is a cluster:
It is not enough to have equipment alone. It is also necessary to organically connect and coordinate with each other to present a cluster to the outside world. This is a development in "cloud is equipment".
Cloud is IT system:
The cluster mentioned above is just a bunch of servers put together and can cooperate. If you want to develop further, you need to add software as the soul, such as the IT system of an enterprise.
Cloud as a Service:
The IT system is generally used to support the business of the enterprise, but can we make profits through it? This is related to the business model. There are mainly the following modes:
sold outright:
If it is like selling a house, the audience is small, because there are very few people who need to buy a complete IT system.
rent it out:
Just like renting a house, the audience is much larger than selling a house. But profit is slow
Use IT systems to run a business to make money:
This method has a larger audience, such as mailboxes, web pages, and blogs. Almost all people are customers, so the profit margin is huge. In this way, a complete set of IT systems that can provide some form of IT service is the cloud. From this perspective, all Internet operators, such as major websites, are cloud operators.
define cloudSo what is the most mainstream definition of cloud at present?
As mentioned above, the equipment forms a cluster, and the cluster is called an IT system with software, and the IT system is used for services. Well, we can combine the previous points to define the following:
Cloud is an operational IT system,
But the most critical thing missing from this definition is the rapid and flexible deployment and recycling of resources. Therefore, the current most mainstream definition of cloud is:
The cloud is an intelligent IT system that:
operational
Can be deployed quickly and flexibly
quickly recyclable
that is
Cloud is an intelligent IT system that can be operated, rapidly and flexibly deployed and reclaimed resources.
Then the cloud should have the following properties:
The cloud provider has a hardware base (computing, storage, networking) of a certain scale
Trading as a service, not a physical transaction, the client simply rents the resource
That is to say, the cloud is actually a business model. It is very narrow to think that only the underlying system using hardware clustering and virtualization technology is the cloud.
Who gave birth to the cloud? Of course demand
Problems with traditional IT
The popularization of the Internet and smart terminals has led to an explosive growth of information, and the IT infrastructure (computing, storage, network) is rapidly being saturated.
Can we see how traditional IT works? For example, the operator department has analyzed that the web game business will grow by 20%, so it needs to expand, such as increasing the number or capacity of web servers, database servers, and storage systems, and then need to purchase equipment and follow a series of processes. Long, or even slower than the business change cycle.
But another department's online video business has a utilization rate of less than 60% due to poor performance.
Of course, the most original idea is to allocate 40% of the online video business to the online game department, but there will be a lot of technical risks. For example, if two businesses are deployed on the same operating system, the viscosity of the business will increase, which is not conducive to operation and maintenance. However, if the business is deployed on different servers, it is even more unfavorable for operation and maintenance.
In addition, there are different protocols and equipment from different manufacturers in the data center. If you deploy, manage and recycle resources manually, the efficiency is low and error-prone, and the speed of business online is not fast.
Let's summarize, there are three problems with traditional IT systems:
Long service deployment cycle
Resources cannot be fully recycled and there are isolated islands
Manual deployment is not enough.
This is the pain point.
Cloud is actually a business model
However, the above statement is only part of the reason for the birth of the cloud. In fact, the original cloud is actually a business model. When the business model is combined with computer technology, the synonym of cloud is born. That's why the cloud doesn't have externally strict standards like technology.
To solve the above-mentioned long service deployment cycle, inability to automate, and inconvenient recycling and reuse of resources, the easiest technical means to think of is virtualization.
Server virtualization, that is, virtual machine system, makes full use of resources, coupled with technologies such as VmoTIon and DRS (Distrubted Resource Scheduler), which greatly increases deployment flexibility and resource balance.
Let's take a look at the changes to the previous problem after deploying the virtual machine.
The problem of full utilization of resources: the old business margin will be automatically recycled, and the applications required by the new business can be directly deployed on the physical machine in the form of virtual machines.
The problem of long online business cycle: deploying virtual machines consumes much less time than physical machines, and the online speed is faster
Manual Deployment Issues: Use a resource automated allocation and recycling platform to solve automated deployment issues.
Then the so-called virtualization is actually adding an elastic layer to the traditional data center, so that the entire data center becomes a soft data center.
If you can also deploy a data center that is automated, measurable, service-oriented, and operable, then it is a cloud data center.
To sum up, the important roles in the cloud system are:
Virtualization
clustering
Automation: managers who realize automatic deployment, scheduling, allocation, and recycling of resources
Internally can communicate with other components and manage resources
It can respond to the needs of business deployment externally, and convert these needs into internal resource scheduling
This module is collectively called "automation".
Measurable:
That is, what resources are used by the user, how long is the duration, how much is the cost, how much the gross profit margin is, and how many quotations can be accurately measured and priced.
Throughout the process of cloud development, it is unclear whether the business model of the cloud came first or the technical architecture of the cloud came first. In fact, the two are mutually reinforcing and complementary.
Review the technical development process of storage systems.
In the beginning, the storage system only needs to care about data storage, as long as a space is provided, how to manage and use it, the bottom layer does not care.
Later, storage systems began to focus on data management and developed functions such as snapshots, deduplication, and disaster recovery.
Later, in the data operation stage, we are still concerned about how to use the data. At this time, we need to apply applications that are closer to users and focus on business presentation.
Now that we have a cloud-based data center, we can divide the data center into private cloud and public cloud according to whether the data center is open to internal services or to anyone:
Private cloud: The data center develops the enterprise internally and provides cloud services, such as storage space application, rapid deployment of enterprise application systems, etc.
Public cloud: It operates externally and provides various cloud services through the Internet.
Private cloud transforms the role of enterprise IT
The traditional IT department is a support department and is always under the traction of the business department. All procurement and funding applications must be based on business needs.
So how to improve the status of the IT department, as long as it has to be on an equal footing with the business department. The word "service" in the cloud just meets this need. For example, the IT department can establish a standardized resource application process, and then establish an electronic work order approval system, and only provide corresponding services after approval. You can also count how many IT resources a department uses and how much cost it consumes during a certain period of time.
In this way, the IT department has become an independent service role. When other departments apply for resources from the IT department, they use a negotiating attitude rather than a strong restraint attitude, and because the resources are measurable, the IT department can make reasonable predictions and apply for resources. Resources such as follow-up funding become more persuasive.
Public cloud is subject to the development of Internet bandwidth
Nowadays, the access speed of the Internet is still relatively low, and the speed of a large number of users is still 1Mbps, that is, the access speed of only 100KB/s throughput. At this time, if it is unrealistic to give him a storage space accessed by the iSCSI protocol, at most upload and download services such as a network disk are provided.
Commonly used SaaS services (web pages, chat, video, network disk, etc.) can basically be based on low-speed networks, but IaaS is difficult. For example, when accessing virtual machines, if you use the virtual desktop instead of xshell to log in, 1Mbps is very barely. Moreover, if you want to install the software, you have to upload the installation package.
To sum up, the most widely promoted place for cloud is to build new data centers, enterprises to build private clouds, and operators to build hybrid clouds
Cloud system architecture and composition
The following figure shows the specific architecture of the cloud:
Divided into the following levels
Physical architecture layer: such as power supply, heat dissipation, etc.
Basic IT architecture layer: including network, storage, server, etc.
It should be noted that these servers and storage devices are not isolated islands, they will form clusters with virtualization and automated management.
Infrastructure/Cluster Management
It's not enough to have a cluster, you need to overlay a virtualization layer on it to increase the elasticity of the system.
For servers it is a virtual machine platform like VMware. For storage, only distributed file systems or distributed volume management systems can meet this demand.
Resource deployment layer:
Now we can get a network, server, storage cluster, and also need a role to manage and drive the cluster.
For example, VMware's Vsphere can package computing resources, and distributed systems can package storage resources.
Using VmoTIon and DRS provided by VSphere can flexibly move virtual machines among cluster nodes, and automatically allocate and recycle resources dynamically.
middleware layer
The application layer and the resource layer need a middle layer to adapt, which is the middleware layer
application engine layer
This layer needs to provide a common business development platform, which can realize unified release.
Business presentation and operation layer
Now the architecture of the data center has the form of clustering, virtualization and automation, but this is only useful for themselves. For users, they do not need to care about whether the underlying layer uses clustering or virtualization, but only care about whether they can get fast services and services. response
So we also need a business presentation interface, which is cloud service.
Then renting a data center can actually be carried out in the following levels:
Infrastructure as a Service (IaaS)
The so-called infrastructure refers to the hardware facilities in the cloud system, such as servers, networks, and storage. Therefore, IaaS only provides a hardware platform, and specific computing tasks are deployed by users themselves.
How to sell storage space:
There are many ways, such as selling bare space, file storage space, etc.
Bare space means that what the end user sees is a hard disk. Of course, ISCSI is preferred for all protocols, so as to span the IP network, so that the user can connect to the ISCSI Target of the cloud provider through the ISCSI IniTIator, and then can obtain multiple LUNs.
For storage systems in the cloud, thinning and deduplication should be necessary to reduce unnecessary space occupation, and dynamic tiering can further save storage costs.
How to sell servers, virtual machines
There are several features to consider for a virtual machine platform:
One is dynamic migration, that is, virtual machines can be migrated between physical machines without affecting the application system.
The second is dynamic resource allocation and scheduling,
The third is convenient management.
Amazon provides two products in IaaS: Elastic Computing Cloud (ElasTIc Compute Cloud, EC2) and Simple Storage Service (Simple Storage Service, S3), corresponding to host computing clusters and storage clusters respectively
Platform as a Service
Compared with IaaS, PaaS shields and does not rent out infrastructure, but instead rents out a higher-level software platform. Users can make applications through this platform. Because this platform is a software that runs in a hardware cluster, users are actually renting computing services.
Software as a Service
SaaS is the outermost layer of cloud services that sells business-level content directly. such as web pages.
example cloud
Let's use the example of 3Tera Applogic to talk about the IaaS layer
3Tera's IaaS platform, named Applogic, is a software virtualization platform that cannot implement IaaS functions. We can take a look at its underlying architecture:
Mainly divided into 4 levels:
Hardware layer:
This layer includes servers, storage, network facilities, etc.
Applogic does not require that the underlying storage must be SAN-based, it can be a local IDE. Several servers are connected by Gigabit Ethernet to form a cluster.
Then, on this limited resource pool with inflexible allocation, a virtualization layer that is easy to manage, easy to use and flexibly allocates resources is implemented.
Distributed core virtualization layer (Applogic OS):
Compute Virtualization: Distributed Virtual Machine Manager (DVM)
The core of this layer is virtual machine technology, which is virtualized into multiple hosts through the Hypervisor engine. For example, VMware's ESX Server achieves this purpose. It's just that Applogic uses the Xen virtual machine platform.
Storage virtualization: Global Volume Store (GVS) sublayer:
Applogic uses a self-developed distributed file system, and a Volume is virtualized on this file system, and the Volume can be Mirror, Clone, Snapshot, etc.
Each Volume is mirrored on multiple physical hosts to solve HA problems and improve read performance.
These volumes are raw disks for the final virtual machine. On this virtualization layer, each node contributes its own local storage space, and the storage of all nodes is integrated for virtualization.
Network resource virtualization: Logical Connection Manager (LCM): Turn physical network into virtual network
One-time infrastructure virtualization layer
The so-called one-time infrastructure actually means that virtual machines can be created on demand. Each application can be assigned a separate infrastructure, including firewalls, load balancing, web servers, database servers, and more. When you want to delete the application, you can delete the virtual machine directly.
These characters can be virtualized into objects, and objects can be created by dragging and dropping with the mouse in the graphical interface.
The above figure creates a firewall, load balancing, two web firewalls, and database servers. Volumes in the entire grid are isolated according to applications, and different applications can only see their own volumes.
Users do not need to care about the IP users interconnected between firewalls, load balancers, and WebServers. The system automatically allocates them. The only thing that needs to be configured is the IP address information of the overall Application.
Network control layer and application management layer
Delivered to users in units of Application.
The revolution brought by Applogic is to simplify the complex underlying hardware, state its own infrastructure by dragging and dropping objects, and finally deliver it as an overall server & storage & network suitable for running an application.
Before looking at the disadvantages of the cloud, look at the advantages of the cloud:
Avoid wasting resources:
energy saving
role change
Existing problems:
Stability and security: how to solve the problem of intercommunication between two storage resources and how to ensure complete isolation.
Platform Migration
How can we migrate to the cloud platform without affecting the business.
Incompatibility: Different cloud service providers provide different architectures and different interfaces.
Evolution after the cloudThe nature of the cloud
The essence of cloud is a kind of service, not a kind of material. Because of this, it must be based on material to show its effect. The Book of Changes has a cloud: "The metaphysical is called the Tao, and the metaphysical is called the instrument". Therefore, the lower part is called server + storage + deployment management software; the upper part is called "cloud". Therefore, the cloud is a way, a way and a method, not a certain device or a certain software. Of course, the cloud needs to be carried by hardware + software.
So, cloud and speed performance are not directly related. The cloud itself is not necessarily a high-speed and high-redundancy thing, but the underlying hardware generally uses parallel computing clusters and storage clusters. On this basis, the cloud can show greater efficiency.
And the cloud is not born to speed up, its main purpose is to use resources cheaply and efficiently and reduce the application cost and management cost of hardware.
In fact, the cloud has existed for a long time, and it has only been hyped in the past two years. Internet servers are cloud services, so some people propose that IT services are cloud, and everything as a service.
In fact, 40 years ago, we still used centralized time-sharing computing. Then, in the commemoration of the intersection of centuries, users purchased infrastructure for computing and storage, and then gradually returned to the era of centralized computing. In fact, this is neither evolution nor Degeneration means "a long division must be reunited, and a long period of cohesion must be divided. All things develop continuously in reincarnation, and return to their original form to a certain extent, but the substance that carries it is continuously improved. What is reincarnated is only the layer above it. Energy is the way.
Micro, Mini, Normal, Huge, Grid elastic data center
Elastic core or soft data center: Pack several blades, high-density disk cabinets and micro switches into one or several cabinets, and then cover with elastic layers, such as virtual machine management systems and distributed storage systems, to integrate such a micro elastic The soft core is delivered to users as a whole that can provide IaaS services.
Or overlay a layer of business on this soft core and present it to the management layer, and deliver it directly to the SaaS layer. The elastic infrastructure delivered by one cabinet or several cabinets can be called Micro Cloud
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