Programmer Think

1, issue description Recently, a mysql binlog data extraction maxwell process in prod environment was monitored by prometheus. There was a problem in its operation. The monitoring showed that the process hung up frequently. Because the maxwell instance service is under systemct service control, it will automatically pull up the program 20 seco ...

Binocular vision is based on geometric mathematics, and mathematical derivation is boring. Therefore, I will not introduce the mathematical principles here, but briefly describe the process of binocular vision. Binocular vision mainly includes five parts: camera calibration, image distortion correction, camera correction, image ...

1, Foreword Most configurations can be replaced by Java class + annotation, and the @ SpringBootApplication annotation is the most common annotation in SpringBoot project, which is marked on each SpringBoot startup class. How does this annotation affect the startup and automatic configuration of SpringBoot? This article will analyze its sourc ...

preface In the traditional system, if the log output can be provided, it can basically meet the requirements. However, once the system is divided into two or more systems, plus load balancing, the call link becomes complex. Especially in the direction of further evolution towards micro services, if there is no reasonable planning of logs and ...

preface Among the queues provided by jdk, there are blocking queues and non blocking queues Blocking queue refers to: when adding elements, if the queue is full, the currently queued thread will be blocked, and the queued thread will be put into the synchronization condition queue of AQS. After the queue element is out of the queue, it will tr ...

1, Overview We know that in HashMap, the location of a key value pair stored in the internal data of HashMap is related to the hashCode value of K, which is also because the hash algorithm of HashMap is based on the hashCode value. Three concepts should be distinguished here: hashCode value, hash value, hash method and array subscript hashCo ...

4.13 ThreadState, yield, join, getState, priority, daemon, interrupt, synchronized, thread communication ThreadState Thread status: Newborn status: new Thread() Ready status: the start() thread will enter the ready queue and wait for the cpu to schedule Running state: when the thread in the ready queue is scheduled by the cpu, it enters the e ...

Spring Cloud Alibaba Seata handles distributed transactions Distributed transaction management preface I don't want to post this blog, because the transaction rollback function is not perfectly implemented. If you see this blog, just understand it. If there is a solution in the future, I'll update it. Distributed transaction Before di ...

1. Reasons for performance degradation and slow SQL query ① Low performance of query statements; ② Index failure single value / composite index; ③ Too many associated queries and too many JOIN associated databases will also lead to too slow queries (design defects or business requirements) ④ Server tuning and parameter setting (buffer / thr ...

9.1 hash table (hash) - Google questions Let's take a look at the actual demand. A computer problem of google: In one company, when a new employee comes to report, it is required to add the employee's information (id, gender, age, address...). When entering the employee's id, it is required to check Find all the information of the empl ...