Programmer Group

Shell distribution script principle In the cluster, we often have this requirement: copy files to the same directory of all nodes in a circular way, and use commands separately from one node to another to improve efficiency. Core idea Encapsulation on rsync rsync command analysis characteristic rsync remote synchronization tool rsync is mainly ...

preface What is monkey patch in python?, What are the usage scenarios? Monkey patch is mainly used for the following purposes: Replace methods, properties, and so on at run time Add previously unsupported functions without modifying third-party codes Add a patch to the object in memory at run time instead of adding it to the source code on dis ...

Source: https://zhenbianshu.github.io/ Some time ago, our service encountered a performance bottleneck. Due to the urgent demand in the early stage, we didn't pay attention to the optimization in this regard. It's very painful to pay off the technical debt. Under very low QPS pressure, the server load can reach 10-20, the CPU utilization rate ...

Proxmox virtualization environment, PVE for short, is an open-source and free enterprise virtualization scheme based on linux, and its function is not inferior to VMware at professional fees. In short, PVE is a linux system based on Debian. It has built-in a set of virtual machine management tools and provides Web management pages, so that we ...

prefaceFlyway, a management database version framework, has been introduced into the project recently to solve the problem of chaotic database script iteration. It's a shame that the company has always manually iterated the database version and configured the init SQL component of MybatisPlus.I have always felt that there is no problem, but eve ...

If Hadoop has not been configured, you can click the link to see how to configure it Basic technical teaching and practical development teaching of major technologies (under continuous updating ··················&middo ...

In the process of developing applications, the ideal state is not to have errors. Even if errors occur, they should be detected during compilation. However, in reality, errors will occur from time to time when the program runs, which will not be expected. If ignored, it will lead to program crash.In C language, the program will indicate the err ...

In addition to the MLFQ mentioned in the previous article, another scheduling policy is called proportional share / fair share. The goal of this scheduling policy is to control the proportion of CPU time occupied by each process. An early implementation of this policy is called lottery scheduling, which means that processes that should run long ...

Experiment 4 design and implementation of neural network algorithm for handwritten digit recognition 1, Experimental purpose By learning BP neural network technology, handwritten digits are recognized, and the recognition rate is improved by structure based recognition method and template matching method. 2, Experimental equipment PC matlab ...

A group of salesmen follow up the national sales orders. They are divided by city. One salesman follows up the orders of three cities. In order to protect the company's business data from being mastered by everyone, each salesman can only see the order data of his own responsible city. Therefore, in terms of the system, each business representa ...