• Google File System


    Design The system consists of a large number of cheap machines. Component failure is a common phenomenon, which needs to monitor the operation, fault tolerance and recovery Most files exceed 100MB, GB level is common and is the main optimization object. Small files are supported, but high efficiency is not guaranteed Read operations include streaming […]

  • 5g Revolution: how to maximize the performance of “data”?


    one As early as the mid-2000s, h-store was first proposed by us in M.I.T. voltdb is a commercial product of h-store, which means that data with similar structure will be stored together continuously. In the subsequent description of this article, we will use V-H for abbreviation.The design of V-H (started in 2004) emphasizes the maximum […]

  • Mongodb tutorial collection


    After stumbling and stumbling, our mongodb series of tutorials finally came to an end. From the first one on November 21 to now, we have been wandering for a while, but fortunately there is no unfinished work. Well, here I’ll list all the articles in this series for my friends to search and view. 1.Installing […]

  • Clickhouse series – fanwai – zero copy


    This article will explain to the reader in detail the underlying details of 4K for each read when unordered storage is mentioned in Chapter 3. The appendix in Chapter 3 has explained to the readers that “this reason is that when the operating system reads the disk, according to the principle of data locality, it […]

  • Problems caused by Mongo flowcontrol


    mongo flowcontrol When Mongo replica sets are deployed, Mongo writes to the default write priority. If the slave node lags too far behind or there are hung replicas, and the number of replicas is less than half of the replica set data, Mongo will actively appear the flow control. View the flowcontrol configuration of the […]

  • Range and index in c#8


    Source:https://note.guoqianfan.com/2021/07/13/Range-and-Index-in-csharp Range range Range operator Range operator:.., it generates aRangeObject. Syntax:{startIndex}..{endIndex}: containsstartIndex,Not includedendIndex limit:0 <= startIndex <= endIndex <= arr.Length, others will report errors! startIndexbe equal toendIndexIf the element cannot be retrieved, anEmpty array。 be careful: By default,..In front of the is0, followed byarr.Length(excluding)。..Equivalent to0..arr.Length。 therefore..Front and back ofCan be empty。 therefore..It can also be […]

  • Python built-in data structures list, set, dict, tuple (II)


    #Difference between value transmission and address transmission #For simple values, the value transfer operation is adopted, that is, the operation of parameters in the function does not affect the external variables #For complex variables, address passing operation is adopted. At this time, the parameters in the function and external variables are the same content, #Changes […]

  • [mongodb] transaction


      summary Mongodb 4.0 supports multi document transactions for replica sets Mongodb 4.2 supports multi document transactions in fragmented clusters A single server does not support transactions, so to learn transactions, you need to build a replica set / fragment cluster In addition, it should be noted that a single document operation is an atomic […]

  • Three parameter analysis of MySQL replication


    This Tuesday morning, I got up late and was late for work. It was… Not much nonsense. In yesterday’s article, we mentioned three parameters, namely: slave_ exec_ Mode parameter; sql_ slave_ skip_ Counter = n parameter; Slave skip errors = n parameter. These three parameters can solve some specified errors in parallel replication, such as […]

  • How to quickly copy and paste file names for Mac


    In our daily work, we often need to use the file name, so how can we quickly copy and paste the file name? Now Xiaobian will teach you some practical tips. Operating skills: Select a file or folder, press command-c, and create a new folder with command-shift-n. at this time, the folder name “unnamed folder” […]

  • C + + multithread correlation (thread, mutex, atomic message queue) under Linux


    environment wsl ubuntu 18.04 LTS gcc version 7.5.0 In fact, this is not important, just a sense of ceremony, HH。 However, it must be implemented under Linux system. It is not allowed on Windows platform. C + + does not use this library to implement multithreading on Windows platform Time slice rotation code #include #include […]

  • Cap theory


    Series articles: Distributed algorithm Cap theory Cap theory Consistency availability partition tolerance uniformity Consistency means that each read operation of the client, no matter which node is accessed, either reads the same latest data or fails to read. As you can see, consistency emphasizes not data integrity, but data consistency among nodes. For example, the […]