1.1 Average Load and CPU Utilization These two are usually key indicators to measure the current performance of the system, but you can’t just study one and give up the other, you need to view and analyze the two together. Average load: Refers to the operating status of the system and the number of processes in the uninterruptible status per unit time. ***CPU usage: It refers to the usage of CPU, which is also our common understanding.

1. Background introduction 1.1 Prometheus The Chinese is Prometheus, just by hearing the name, I feel very fanciful, and it is a very powerful thing. Let me talk about the story of Prometheus, he is a figure in the myth of Athens, the legend is that he fabricated the human form, and Athena gave each human form a soul. Zeus forbids humans to use fire. Seeing that humans are in distress, this buddy stole fire from Apollo, so he offended Zeus.

1. Purpose This summary is to review the related operations of adding practical Nginx. Including three major features of Nginx: load balancing, reverse proxy and dynamic and static separation. Finally, use Nginx to simulate a high-availability scenario to deepen your understanding of Nginx. 2. Basic concepts 2.1 Nginx description Nginx is a reverse proxy web server for http, which performs well in concurrency and can withstand up to 50,000 concurrency. So it is also favored by many companies.

This summary may not cover all HTTP knowledge points, but it is just based on my own understanding, and then combined with online information to summarize. 1. What is HTTP HTTP (hypertext transport protocol), is the hypertext transfer protocol, text can be understood as characters, text, audio and video, etc. Hypertext is not a simple text file, but a more complex mixture of various files. In fact, it is very easy to understand.

1. What is Nginx? From Google result, Nginx is a free, open-source, high-performance HTTP server and reverse proxy, as well as an IMAP/POP3 proxy server. Nginx is known for its high performance, stability, rich feature set, simple configuration, and low resource consumption. Nginx supports up to 50000 concurrent applications. 2. Forward And Reverse Proxy The forward proxy is a proxy server between the client and the target server. In order to obtain content from the original server, the client sends a request to the proxy server, and specifies the target server, after which the proxy transfers to the target server and returns the obtained content to the client.

1. Concept When it comes to trees, we must first talk about linear structures and nonlinear structures. The meaning of the data structure is to construct a set of interrelated data models, and then cooperate with the algorithm to solve some time-consuming operations in the computer. Linear and nonlinear are two very important data models. Linear structure: The relationship between data elements is one-to-one, and the data elements echo each other stack queue linear table array string Non-linear structure: the relationship between elements is not one-to-one, and each element may have a relationship with zero or more other data Two-dimensional array Multidimensional Arrays generalized table Tree picture So the concept of a tree is very clear.