Tag:node

  • Spark installation and configuration

    Time:2022-1-19

    1. Spark Download https://archive.apache.org/dist/spark/   2. Upload and decompress, configure environment variables, and configure bin directory Unzip: tar -zxvf spark-2.4.5-bin-hadoop 2 7.tgz -C /usr/local/soft/ Renamed: mv{spark-2.4.5-bin-hadoop 2 7/ spark-2.4.5 Configure environment variable: VIM / etc / profile Add environment variable: export SPARK_HOME=/usr/local/soft/spark-2.4.5export PATH=$PATH:$SPARK_HOME/bin Save configuration: source / etc / profile   3. Modify the configuration […]

  • Store a tree in the database to realize infinite classification

    Time:2022-1-19

    The original text is published on my blog: https://blog.kaciras.com/article/6/store-tree-in-database In some systems, classifying content is a necessary function. For example, e-commerce needs to classify goods to facilitate customer search; The forum will also be divided into many sections; The portal website also has to classify the content of the website. Classification is indispensable for a […]

  • Pulsar vs Kafka? Master the basic knowledge of high-performance message component pulsar

    Time:2022-1-19

    What is pulsar? Apache pulsar is a top-level project of the Apache Software Foundation. It is a native distributed message flow platform for the next generation cloud. It integrates message, storage and lightweight functional computing. It adopts a separate architecture design of computing and storage, and supports multi tenant, persistent storage and multi machine room […]

  • The architect’s path – HTTPS underlying principles

    Time:2022-1-19

    Introduction Part IThe architect’s path – HTTPS underlying principlesI mentioned the above overall view, and the article also introduced the basic skill of really solving problems in time and correctly at work: a thorough understanding of the principle. Today, take redis cluster analysis as an example to introduce the basic skill of timely and sensitive […]

  • React usestate implementation

    Time:2022-1-19

    Implemented functions Realize the basic functions of usestate, value taking and value saving Problems to be optimized In a certain period of time, the DOM is updated after the state to be updated is processed uniformly. At present, it is updated once and rendered again It cannot be introduced into the react environment for the […]

  • [elasticsearch technology sharing] – common terms and structures of ES

    Time:2022-1-19

    preface After reading what elastic search is and understanding the concept of inverted index, let’s get familiar with some common nouns in ES. Common terms noun explain cluster If one or more nodes specify the same cluster name, they will form a cluster and automatically elect the master and in case of failure. node The […]

  • Interview tutorial – sorting out Java collection knowledge

    Time:2022-1-18

    1、 ArrayList ArrayListThe underlying data structure isDynamic arraySo we can call it array queue.Dependencies of ArrayList: public class ArrayList<E> extends AbstractList<E> implements List<E>, RandomAccess, Cloneable, java.io.Serializable It can be seen from the dependencies that ArrayList is first a list. Secondly, it has list related functions and supports rapid (fixed time) location of resources. You can […]

  • Not only on the cloud, but also ashore

    Time:2022-1-18

    author Chang yaoguo, an expert of Tencent SRE, now works in PCG big data platform department and is responsible for the cloud, monitoring and automation of tens of millions of QPS services. background Beaconlogserver is the portal for lighthouse SDK to report data. It receives data reports from many services, including micro vision, QQ, Tencent […]

  • [elasticsearch technology sharing] – elasticsearch stores a piece of data. What is the put process like?

    Time:2022-1-18

    preface Some terms commonly used in es have been introduced earlier. We know that data is stored in shards, and index will map one or more Shards. At this time, I want to store a piece of data under an index. Which index is this data under? Es demo All in accordance with the official […]

  • Adaoracle Oracle is an indispensable part of the blockchain

    Time:2022-1-18

    According to official news, adamsorcle has officially launched the second phase of its two-week wide area node network test, and invited global nodes to participate in the million incentive test competition StarCraft. As of October 30, in only three days, the computing power of the whole network of adamor has exceeded 100p, and the number […]

  • Downloader synchronization of dieke Ethereum source code analysis

    Time:2022-1-18

    Downloader synchronization of dieke Ethereum source code analysis Need to match the comment code to see:https://github.com/blockchain… This article is long. What you can read is a man. I suggest collecting it I hope readers will point out problems, pay attention to them and discuss them together in the reading process. overview downloaderThe code for the […]

  • Master-slave replication of redis high availability

    Time:2022-1-18

    Redis high availability Redis master-slave Cap principle C: Consistency A: Availability P: Partition tolerance Nodes in a distributed system are often distributed on different machines for network isolation, which means that there is a risk of network disconnection. The professional vocabulary of this network disconnection scenario is called network partition.When the network partition occurs, the […]