• CentOS install elasticsearch


    1、 Download Download address: https://www.elastic.co/downloads/elasticsearch Historical version: https://www.elastic.co/downloads/past-releases#elasticsearch If the machine can access the Internet, it can also be downloaded directly by WGet shell> wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.6.4.tar.gz 2、 Install (unzip) Es runs in Java environment, so you need to install JDK first. There are a lot of online tutorials, so you can refer to my other […]

  • Replace binary search tree with cumulative tree (Python 3)


    Put forward the problem: given a binary search tree, convert it into a greater tree, so that the value of each node is the sum of the original node value and all the nodes greater than it. Solution: use a new traversal method (right subtree, root, left subtree) to traverse the whole tree. Set the […]

  • Distributed classic architecture


    introduction As we know, distributed system is to deploy system units with independent computing capability on different machines. So, how to effectively manage the cooperation between these machines is a big problem. At present, there are two typical distributed system architectures: centralized and decentralized. Centralized Architecture We can compare each node in a distributed system […]

  • (13) C ා WinForm custom control – navigation menu – hzhcontrols


    Official website http://www.hzhcontrols.com premise Has been in the industry for 7,8 years, has always wanted to do a set of beautiful custom controls, so there is a series of articles. GitHub:https://github.com/kwwwvagaa/NetWinformControl Code cloud: https://gitee.com/kwwwvagaa/net_ winform_ custom_ control.git If you think the writing is OK, please click a star to support it Welcome to discuss: Penguins […]

  • Linux deployment. NETCORE site uses supervisor for managed deployment


    preface The. NETCORE site was finally deployed on Linux, but this site is “fragile.”. When my SSH connection is closed or I want to execute other commands on the current connection, I have to close the dotnet site executor. This is obviously not the effect I want to achieve. Fortunately, I know that there are […]

  • Springboot + neo4j in social e-commerce, tell how you are bound to offline


    In the last two articles, we mainly explained the basic knowledge of neo4j and the basic use of neo4j. In this article, we take the binding relationship in social e-commerce as an example and use springboot + neo4j to realize it. Review of neo4j articles: Don’t understand neo4j? It’s OK. Learn together Don’t understand neo4j? […]

  • Add two numbers (python3)


    Ask questions:Two non empty linked lists are given to represent two nonnegative integers. Their respective bits are stored in reverse order, and each node can only store one digit. If we add these two numbers together, we will return a new linked list to represent their sum. You can assume that neither of these numbers […]

  • Implementation and time complexity analysis of four common linked lists (Python version 3)


    Four kinds of common linked lists include: one-way linked list, one-way circular list, two-way linked list and two-way circular list.The list operations to be implemented include is_empty()Judge whether the linked list is empty length()Find the length of linked list traversing()Traverse all node elements add()Head add node append()Add node at tail insert(pos, item)Insert node at a […]

  • Change the default parent node of element UI specific component pop-up floating layer


    The cascader selector or TimePicker in elementui and the floating layer after clicking the datepicker selector are directly inserted under the body tag. An appropriate point will be automatically calculated in the elementui to locate the floating layer absolutely. However, in recent projects using the element UI framework, the floating layer of such components cannot […]

  • Redis arranges a complete article


    Redis Redis basic data type Redis supports five data types: String (string) Hash (hash) List Set (set) Zset (sorted set: ordered set) String String: a key corresponds to a value. String type is binary safe and can store any type of data Common commands: get, set, incr, decr, mget, etc hash Hash: a mapping table […]

  • Building big data cluster environment — HDFS ha


    This time, we ushered in the third chapter of “building a big data cluster environment” – HDFS ha. HDFS must be familiar to everyone. Its full Chinese name is “Hadoop distributed file system” (what, why do you think there are English words in the full Chinese name? Anyway, I don’t know how to translate Hadoop. […]

  • MySQL group replication


    Since MySQL group replication was released following 5.7.17, MySQL has really had a mature and highly available distributed cluster solution, which has got rid of the pseudo cluster of master slave + third-party tools. This is the first article in a series of articles on MySQL group replication, which briefly introduces the afterlife and related […]