Ha, cluster, load-balance differences

Cluster)
A cluster is a loosely coupled multi-processor system composed of a group of independent computer systems. It communicates with each other through a network. Applications can transmit messages through the network shared memory to implement distributed computers.
Load Balance)
Server Load balancer is a dynamic balancing technology. It uses some tools to analyze data packets in real time, master the data traffic conditions in the network, and distribute tasks in a reasonable and balanced manner. Based on the existing network structure, this technology provides a cheap and effective method to expand server bandwidth and increase server throughput. It enhances network data processing capabilities and improves network flexibility and availability.

Features
(1) high reliability (ha ). With the cluster management software, when the master server fails, the backup server can automatically take over the work of the master server and switch over in time to achieve uninterrupted services for users.
(2) high-performance computing (HP ). That is to say, we make full use of the resources of every computer in the cluster to implement parallel processing of complex operations, which are usually used in scientific computing, such as genetic analysis and chemical analysis.
(3) load balancing. That is, the load pressure is allocated to each computer in the cluster according to a certain algorithm to reduce the pressure on the master server and reduce the hardware and software requirements on the master server.

 

Load Balance Cluster

There are a total of four brothers opening tailor shops, a lot of business, a person can not do, always delay the construction period, so the four brothers discuss

The boss received the order and the three brothers came to work. After the customer grows, the boss assigns new tasks based on the workload of the three brothers according to certain principles (policies.

High Availability Cluster

The two brothers opened a breakfast shop with little business, but there were a lot of customers between and every morning and they could not be interrupted. In order to ensure that the breakfast shop can continue to provide services within two hours, the two brothers discuss several methods:

Method 1: In normal times, the boss is doing business. The second child is waiting at home. Once the boss cannot do business, the second child comes out to the top. This is called active/standby.

Method 2

Method 3: at ordinary times, the boss sells steamed buns, and the second child also sells soy milk. The old one has a big problem. The second child sells steamed buns and soy milk, and the second child doesn't work. The boss sells steamed stuffed buns again, sell soy milk again. this is called active/active (dual active)

Steamed Stuffed Bun = application package, which is called heartbeat for mutual reference and Failover/takeover for replacement. if the two brothers suddenly become blind and do not know whether the other party is working now, they all think they want to work for the other party. This is called brain-split, and then they need a third party, for example, their father solved the problem. This is called tier-breaker, or they asked two of their daughter-in-law to pull one of them. This is called fency.

Hey hey.

High computing Clustering

Ten brothers work together in the handmade furniture business. One customer came to their father to ask for a very complex set of antique furniture which can also be done by one person, but they have to do it for a long time, in order to hand over the set of furniture in a week, the 10 brothers decided to do it together.

The old man handed the different parts of the set of furniture to his sons for work. Then each son was processing the wooden furniture and finally made a fight for the goods.

He is a scheduler Task Scheduler, and his sons are compute nodes. Their jobs are called jobs.