What is a cluster? What is a Distributed Cluster?

Trunked mobile communication system is a relatively economical and flexible mobile communication system developed in the 70s of the 20th century, and it is the advanced development stage of the traditional private radio dispatching network. Trunking is the use of multiple wireless channels to serve a large number of users.

Trunking is a mobile communication system used for group dispatching, command and communication, which is mainly used in the field of professional mobile communication. The Trunking System Controller dynamically and automatically optimally allocates a limited number of channels to all users of the system, which is in fact channel full utilization or the term "channel sharing" that we often use.

The exhibition is the development of industries together.

Industrial clusters are also known as "industrial clusters", "competitive clusters", and "Porter clusters". Competitive enterprises in a certain industry, cooperative enterprises, professional enterprises, service providers, related industry manufacturers and related institutions (such as universities, scientific research institutions, standard-setting institutions, industry associations, etc.) that interact with these enterprises gather in a specific region.

For example, information technology companies and related manufacturers, related institutions and other gathering in Silicon Valley in the United States. Porter of the United States proposed and discussed in detail in the book "National Competitive Advantage" in 1990. It helps competing enterprises to improve their competitiveness and plays an important role in the development of specific industries and the enhancement of national competitiveness.

The core of industrial clusters is the high concentration of industries within a certain spatial range, which is conducive to reducing the institutional costs of enterprises (including production costs and exchange costs), improving economies of scale and scope, and improving the market competitiveness of industries and enterprises.

From the micro-level analysis of industrial clusters, that is, from the perspective of a single enterprise or industrial organization, enterprises can replace market transactions with higher costs with intra-enterprise transactions with lower costs through vertical integration, so as to achieve the purpose of reducing transaction costs: through vertical integration, the stability of enterprise production and sales can be enhanced.

Through vertical integration, it can form a certain competitive advantage in terms of production costs, raw materials, product sales channels and other aspects, and improve the entry barriers of enterprises; Through vertical integration, enterprises can improve their sensitivity to market information; Through vertical integration, enterprises can enter high-tech industries and high-profit industries.

To put it simply, distributed improves efficiency by shortening the execution time of a single task, while clustering improves efficiency by increasing the number of tasks executed per unit of time.

If a task consists of 10 subtasks and each subtask takes 1 hour to execute alone, it takes 10 hours to execute the task on a server.

Using a distributed solution, 10 servers are provided, and each server is only responsible for processing one subtask, regardless of the dependencies between subtasks, and it only takes one hour to complete this task.

The cluster solution also provides 10 servers, each of which can handle this task independently. Suppose 10 tasks arrive at the same time, 10 servers will work at the same time, and after 10 hours, 10 tasks will be completed at the same time, so that, on the whole, one task will be completed within 1 hour.

Distributed is one of the architecture deployment patterns. Distributed is mostly used to describe architectural design, when there are now various new uses for it.

Capacity cluster is a hardware deployment model, which is a centralized name for a group of computers deployed in a computer room.

The distributed cluster system is a multi-architecture model, which supports the generation of independent and multi-layered, completes the construction of each horizontal integration and vertical integration group, and can share and interconnect information between the main station, sub-station and the main station.

To put it simply: it is an enterprise that individuals can self-help to build, maintain, and update websites like applying for blogs, and distributed means that problems are solved separately, that is, the system is distributed on several different servers.

N machines work together to complete computationally intensive tasks, mainly distributed.

If you are interested, you can go to the Internet to find Google's three public articles about gfs, bigtable, and mapreduce, which have Chinese translations.

The cluster system is one bai

A multi-frame DU structure mode, supporting the generation of independent network DAO stations, multiple **, and completing the integration of each horizontal and special direction.

The construction of the genus and vertical integration group, the information sharing and information interconnection between the main station, the sub-station, and the first station, simply put, is that an enterprise individual can self-help website building, maintenance, and update like applying for a blog, and distributed, that is, the problem is solved separately, that is, the system is distributed on several different servers, generally for the following three situations:

1。A single server can't handle the pressure.

2。It is necessary to realize automatic switching when an error occurs.

3。Learn or test distributed technologies.

Below is a link, a simple technical report, you can take a look.

Cluster: A group of independent, interconnected computers via a high-speed network, which form a group and are managed in a single system mode. When a customer interacts with a cluster, the cluster is a separate server.

Cluster configurations are designed to improve availability and scalability. Compared with the traditional high-performance computer technology, the cluster technology can use the servers of various grades as nodes, the system cost is low, the computing speed can be very high, the calculation of large computing volume is completed quickly, and the response ability is high, which can meet the growing demand for information services.

Cluster technology is a general technology that aims to solve the shortcomings of single-machine computing power and I/O capabilities, improve service reliability, obtain scale scalability, and reduce the O&M cost of the overall solution. As long as other technologies cannot achieve the above purposes, or although they can achieve the above purposes, the cost is too high, the cluster technology can be used.

Clustering means clustering.

Ji is a commonly used Chinese character, which was first seen in the Shang Dynasty. The ancient character of the set is like a branch on a bird, and some are like three birds gathered on a tree, the original meaning refers to the gathering of many birds on the tree, and by extension, it refers to the convergence and confluence, and also refers to the market and market town where the crowd is concentrated.

The early Jizi were written in a variety of ways, and the Shang Dynasty oracle bone inscription and the Shang Dynasty Jin inscription were both pictograms of birds on the ridge of a tree. Simplified Chinese characters for a bird in a tree. In ancient times, it was difficult to distinguish between the eagle and the bird, and it was originally one word, and later it was divided into two words for filial piety.

The traditional Chinese characters are made of three birds on the tree, and the three birds are 雥, which has evolved into the sound of the voice, and the sound of the gong is the same as the rhyme of the set. The traditional Chinese glyphs have been developed by the small seal of "Shuowen Jiezi", and the structure is in the same line, and the regular script is finally used as a wolf.

Set words to form sentences

1. The tenderness of the flush in the heart is condensed on the fingers, and the fleeting broken shadows flow silently and tactfully on the fingertips, gently gathering, slowly distorting the dust of the years.

2. Under the optimized spinning conditions, the regenerated silk protein fiber with good aggregation structure was successfully spun.

3. On a clear night, the sky becomes a gathering place for stars, and the twinkling little stars are like many small lanterns, which embellish the monotonous night sky.

4. On the way out of school, I hummed a wordless tune softly, and naturally looked up, and saw that pieces of dark clouds gathered on it, like the shade of a tree under a big umbrella.

5. In the morning, when I opened my eyes, I heard the sound of rain outside, which was the sound of the rain falling on the balcony after gathering on the roof, ticking, like the sound of time slipping away.

The above content reference: Encyclopedia - Collection.

1) Strong scalability.

Other scaling technologies usually only support the expansion of 10 CPUs, and the scaling capacity is limited. The cluster system using cluster technology can be extended to multiple service spikes including hundreds or thousands of CPUs, and the expansion capability has obvious advantages. Cluster services can also be continuously adjusted to meet the needs of growing applications.

When the overall load of the cluster exceeds the actual capacity of the cluster, additional nodes can also be added.

2) Easy to implement.

Server clustering technology is easier to implement than other scaling technologies and is mainly done through software. In terms of hardware, a number of low-performance, low-cost servers can be connected together through cluster services to multiply or even multiply the entire server system.

10. Hundreds of times more. Both in terms of software and hardware composition costs, as well as in terms of technical implementation costs, they are lower than other expansion methods.

3) High availability.

Use the cluster service to take ownership of the entire cluster system resources. Such as disk drives and IP addresses will be automatically transferred from the faulty server to the available server. When a system or application in a cluster fails, the cluster software restarts the failed application on an available server, or distributes the work on the failed nodes to the remaining nodes.

During the switchover, the user simply felt that the service took a momentary pause.

4) Manageability.

You can use the cluster manager to manage all the server resources and applications of the cluster system as if they were all running on the same server. Applications can be moved between different servers in the cluster by dragging and dropping cluster objects, data can be moved in the same way, and server load balancing and offloading can be manually done in this way for easy maintenance. At the same time, the status of the cluster can be monitored from nodes and resources anywhere in the network.

When a failed server is reconnected, it will automatically return to working status, and the clustering technology will automatically balance the load in the cluster without the need for on-worker intervention.