Meituan distributed ID generator (Leaf), which can't be missed, is an easy-to-use batch

Leaf Leaf is a distributed ID generation service launched by meituan. Its name is taken from the words of German philosopher and mathematician Leibniz: "there are no two identity leaves in the world." ("there are no two same leaves in the world"), taking a name has such moral meaning, meituan programmer Niu break! Advantag ...

Posted by Chris_Evans on Wed, 25 May 2022 07:06:18 +0300

[Study Notes] Alibaba Cloud Tianchi Dragon Ball Project SQL Training Camp - Task03: Complex Query Methods - Views, Subqueries, Functions, etc.

s This note is the learning content of Alibaba Cloud Tianchi Dragon Ball Project SQL Training Camp The link is: https://tianchi.aliyun.com/specials/promotion/aicampsql   Practice Questions - Part 1 3.1 Create a view that satisfies the following three conditions (the view name is ViewPractice5_1). Using the product table as a referen ...

Posted by [e]r!k on Wed, 25 May 2022 06:53:14 +0300

Ruan Yifeng great God ECMAScript 6 Introduction notes sorting

Ruan Yifeng great God ECMAScript 6 beginner level: https://es6.ruanyifeng.com/ If you don't like the typesetting here, you can go to my YuQue to have a look. YuQue is really unique https://www.yuque.com/isremya/vqgp35 let and const commands The variable declared by let is only valid in the code block in which it is located.   The variable i ...

Posted by RedMaster on Wed, 25 May 2022 06:43:55 +0300

Visibility between Java array threads

Volatile is usually used in concurrent programming to ensure the visibility between threads, but the elements in the array modified by volatile cannot ensure the visibility between threads. For example, ConcurrentHashMap uses Unsafe way to access u.getobjectvolatile (tab, ((long) I < < ashift) + abase); The following code cannot guarantee ...

Posted by patch2112 on Wed, 25 May 2022 06:42:14 +0300

Install ceph and openstack multi node

Install ceph and openstack multi node network environment hostname network card ip master em1 10.201.7.10 em2 10.10.10.10 em3 Connected to the switch, but no ip node1 em1 10.201.7.11 em2 10.10.10.11 node2 em1 10.201.7.12 em2 10.10.10.12 10.201.7.0/24: it can be connected to the external network, which is the defa ...

Posted by pranesh on Wed, 25 May 2022 06:40:08 +0300

Network Engineering Fundamentals - Dynamic ACL s

Network Engineering Fundamentals - Dynamic ACL Experimental environment: EVE-NG Experimental topology: The underlying configuration (no sh is not typed out, just configure it by yourself): R1(config)#no ip routing R1(config)#ip default-gateway 12.1.1.4 R1(config)#interface e0/0 R1(config-if)#ip address 12.1.1.1 255.255.255.0 R2(config)#no ip ...

Posted by ndjustin20 on Wed, 25 May 2022 06:39:38 +0300

Operating system experiment 11: read / write the specified location information of the disk (just complete the reading)

Experiment 11: read / write the specified location information of the disk (just complete the reading) 1, Experimental purpose (1) Knowledge of Disk Physics. (2) Master the API for disk operation provided by Windows system. (3) Read / write the specified sector according to the entered sector number. 2, Experimental preparation knowledge: intro ...

Posted by floR on Wed, 25 May 2022 06:36:39 +0300

1 construction and traversal of binary tree

Establishment and traversal of binary tree (1) Establishment of binary tree Establish a binary tree by traversing in the first order and in the second order: In the pre order traversal sequence of binary tree, the first element is always the value of the root node of the tree. In the middle order traversal sequence, the value of the node of the ...

Posted by Brandon_R on Wed, 25 May 2022 06:18:05 +0300

Under what conditions is StringBuider more efficient?

introduction It is said that String builder is more efficient than String in dealing with String splicing, but sometimes there may be some deviation in our understanding. Recently, when I tested the efficiency of data import, I found that my previous understanding of string builder was wrong. Later, I found out the logic of this piece by mean ...

Posted by gausie on Wed, 25 May 2022 06:05:45 +0300

PINK teacher HTML5+CSS3 Tutorial 9

Tip: after the article is written, the directory can be generated automatically. Please refer to the help document on the right for how to generate it preface Tip: Here you can add the general contents to be recorded in this article: https://www.bilibili.com/video/BV14J4114768?p=274&spm_id_from=pageDriver Tip: the following is t ...

Posted by theresandy on Wed, 25 May 2022 05:45:41 +0300