Differences and connection between clusters, distributed instances, and Server Load balancer

<Doctype HTML public-wcdtd XHTML stricten httpwwwworgtrxhtmldtdxhtml-strictdtd> 1. Linux clusters are mainly divided into three categories (high-availability clusters, Server Load balancer clusters, and scientific computing clusters) (The following describes only the Server Load balancer clusters)
Load Balance Cluster)
Server Load balancer system: All nodes in the cluster are active and share the workload of the system. Generally, Web Server Clusters, database clusters, and Application Server Clusters belong to this type.

A server Load balancer cluster is generally used as a web server or database server for network requests. When receiving requests, the cluster can check and accept servers with fewer and less busy requests and send requests to these servers. From the perspective of checking the status of other servers, Server Load balancer is very similar to the fault-tolerant cluster. The difference is that the number is more.

2. Server Load balancer system: Server Load balancer also includes DNS Server Load balancer (commonly used), IP Server Load balancer, and Reverse Proxy Server Load balancer, that is, servers A, B, and C are in the cluster, they are all independent and irrelevant. If any machine goes down, it will not affect the operation of other machines. When a user sends a request, there is a Load balancerAlgorithmDecide which machine to process. If your algorithm adopts the round algorithm and has users A, B, and C, the server A, B, and C will process them respectively;

3. Distributed refers to the distribution of different services in different places.
A cluster refers to the combination of several servers to implement the same service.
Every node in the distributed architecture can be used as a cluster.
Clusters are not necessarily distributed.
For example, if there are too many people accessing xinlang, he can build a cluster with a response server in front of it, and the following servers can complete the same business. If there is a business access, the response server determines which server will be completed if the load is not heavy.
In a narrow sense, the distributed architecture is similar to a cluster, but its organization is loose. Unlike a cluster, it has an organizational structure. If one server crashes, other servers can be topped up.
Each distributed node completes different services. If a node crashes, this service is inaccessible.

# Database Technology