• Learn about Flink state backends


    When we use Flink for stream computing, we usually produce various forms of intermediate results, which we call state. If there is state generation, state storage must be involved. What forms of state storage are defined in Flink? Let’s introduce them one by one. State Backends MemoryStateBackend FsStateBackend RocksDBStateBackend MemoryStateBackend As the name implies, the […]

  • From a question to deepen the understanding of MySQL repeatable


    Introduction question This question comes from an after-school thinking question of an online course I use the following table structure and initialization statements as the test environment, and the transaction isolation level is repeatable. Now, I’m going to clear the C values of all rows with equal field C and ID values, but I find […]

  • This is how Maven snapshot version works!


    The mystery of bug’s life Today I share another story about problem solving. Please see the error in the box below. Obviously, we can’t find this class! Let’s check the problem according to the idea of normal people. Since we can’t find the class, let’s see if there is a dependent jar package first. If […]

  • Flink exactly once


    preface Flink’s “accurate once” processing semantics is that Flink provides a powerful semantic guarantee, that is to say, in any case, it can ensure that the data only has one effect on the application, no more, no less. So how does Flink realize the “end-to-end precise one-time processing” semantics? In fact, there are two main […]

  • [finish JVM interview] JDK monitoring and troubleshooting tools


    This article has been included in the author’s open source Java Guide: https://github.com/Snailclimb (a copy of [java learning + interview guide] covers the core knowledge that most Java programmers need to master.) if you think it’s good, you can go to a star and encourage it! Summary of JDK monitoring and troubleshooting tools JDK command […]

  • How can cloud function create 6000 cloud servers in one minute?


    CBS cloud disk snapshot service undertaking cloud server creation task behind decryption Cloud function (SCF) is a serverless execution environment provided by Tencent cloud for enterprises and developers to help users run code without purchasing and managing servers. With the rapid and convenient cloud native service becoming more and more popular, the business volume is […]

  • On the consistent reading of transaction isolation in MySQL


    preface We have known the transaction isolation level of MySQL briefly before. We know that the most commonly used transaction isolation levels in MySQL are repeatable read (RR) and read commit (RC).In RR level, the data read is consistent from transaction start to transaction commit. In this article, we will carefully analyze how consistent read […]

  • Basic process of nexus private service building


    Basic process of nexus private service building What is nexus? A tool for implementing Maven to build a private warehouse. We can use nexus to manage our dependencies. We no longer need to download the corresponding jar package from the central warehouse What is nexus private service? Private server is a kind of special remote […]

  • How does V8 run — object representation in V8


    This article was created on April 20, 2019 and moved to here This article is based on chrome 73. preface V8 may be a familiar and unfamiliar field for front-end developers. When you see this article, it has been iterated over three editions. There is only one purpose. On the premise of ensuring the accuracy […]

  • One article understanding of redis persistence


    Redis persistence RDB snapshot By default, redis saves the memory database snapshot to dump.rdb In the binary of.Redis can be set to “make at least N changes to the dataset in N seconds”. When this condition is met, the dataset will be saved automatically once. For example, when redis meets the condition of “at least […]

  • Install centos7


    Screenshot 2019-08-19 12.52.47 Screenshot 2019-08-19 12.54.19 Screenshot 2019-08-19 12.55.27 Screenshot 2019-08-19 12.55.56 Screenshot 2019-08-19 12.56.27 Screenshot 2019-08-19 12.58.08 Screenshot 2019-08-19 13.00.28 Screenshot 2019-08-19 13.00.18 View host name //Check the current host name and all three host names hostnamectl //Or, view all three host names hostnamectl status //View only static, transient, or flexible hostnames, using the […]

  • 3. VMware snapshot and cluster


    In the previous section, we introduced the creation of virtual machines by VMware, the installation of CentOS 6.5 and the installation of CentOS 7. After the above installation and shutdown, a pure initial environment will be formed. Next, you can take a snapshot to solidify it into a template, so as to clone the template […]