Deep understanding of JVM memory allocation strategies

Understanding JVM memory allocation strategies Three Principles + Guarantee Mechanism There are three main principles and guarantee mechanisms for JVM memory allocation mechanism Specifically as follows: Priority assigned to eden area Big object, directly into the older generation Distribution of long-term survivors to older generations Space ...

Posted by mimilaw123 on Sat, 21 Sep 2019 18:44:34 +0200

3. SpringBoot integrates mybatis multi-data sources and sub-database and sub-table

Preface To be honest, this chapter was not meant to talk about, because there are many similar tutorials on the Internet that configure multiple data sources. But recently, because the project uses sub-database and sub-table, let me study how to achieve it. I think about the last blog about multi-environment configuration, different environment ...

Posted by htcilt on Sat, 21 Sep 2019 14:00:50 +0200

Reds Notes on Mosquitoes - Actual Chapter

Redis Fragmentation Technology requirement analysis If all data is saved in a redis, if the server is damaged, all services will be affected. Using single Redis memory settings generally does not exceed 1G. However, some business data is very large. If memory is not modified, data cannot be stored. ...

Posted by jestaji on Sat, 21 Sep 2019 13:12:52 +0200

Custom Tool Class (Object to Collection Map)

java obtains object attribute type, attribute name, attribute value: https://www.cnblogs.com/gmq-sh/p/5942065.html Using java's reflection What is the role of Class classes? (1) Instances of Class classes represent classes and interfaces in running Java applications. One of the benefits of reflect ...

Posted by private_click on Sat, 21 Sep 2019 08:38:15 +0200

(10) Horizontally expanding the ceph cluster

When the cluster capacity or computing resources reach a certain limit, the cluster needs to be expanded, which can be divided into two main operations:1. Vertical expansion: adding disks to existing nodes will increase capacity and keep cluster computing performance unchanged;2. Horizontal expansion: adding new nodes, including disk, memory a ...

Posted by vandutch on Fri, 20 Sep 2019 19:10:31 +0200

Python - Strings and Common Data Structures

Catalog 1. string 2. list 2.1 Addition, deletion and modification of list Slicing and sorting of 2.2 lists 2.3 Generative Grammar 3. tuple 4. set 5. dictionary 5.1 addition, deletion, modification and search of dictionaries Common operation of 5.2 dictionary ...

Posted by nikefido on Fri, 20 Sep 2019 13:45:11 +0200

Message sending mechanism of kafka producer

Opening a picture, the reader is happier, not to mention the structure chart.This schematic diagram was introduced in the previous article "kafka Producer's Storage Pool Mechanism". In the previous article, we introduced the message collection process (we became the "Storage Pool" mechanism) in this diagram. Here we introduc ...

Posted by emopoops on Fri, 20 Sep 2019 11:22:46 +0200

HTTP API Call for Cloud Development

httpApi calls for small program cloud development. httpApi call for small program cloud development (returning "47001 processing") Technology stack Using node JS + express to build web server and axios to request third party http Api nodejsexpressaxios Project structure An application s ...

Posted by trinitywave on Thu, 19 Sep 2019 13:07:48 +0200

php express logistics single number query api interface demo address free call

With the flourishing development of online shopping era and express industry, people pay more and more attention to express inquiry service. This article provides you with a good PHP source code development program for API interface of express inquiry, such as four-way one-way express, Shunfeng express, daily express, Yunda express and other hu ...

Posted by Earnan on Thu, 19 Sep 2019 12:05:31 +0200

I think Python is too "simple". How many of these questions can you answer correctly?

Preface Think Python is too "simple"? As a Python developer, I have to give you some life experience, otherwise you don't know the heavens and the earth! A 100-point question, this article is to record the pits stepped on in this set of questions. The following code will report errors. Why? ...

Posted by FFFF on Thu, 19 Sep 2019 10:30:55 +0200