Programmer Think

I. Built-in Functions Following is a brief introduction of several: 1. Absolute value of ABS () 2.all() Returns True if all elements of iterable are true (or if iterable is empty). 3.any() returns True if any element of iterable is true. If iterable is empty, return False 4.callable() If the object parameter is tunable, return True or False 5. ...

Prepare data, create data tables Creating Student Information Table students create table students( id int unsigned primary key auto_increment not null, name varchar(20) default '', age tinyint unsigned default 0, height decimal(5,2), gender enum('male','female','Simon?','secrecy'), cls_id int unsigned default 0 ); Create class tables c ...

In the previous article, "Understanding Spark 2.1 Core (9): Iterative Computing and Principles and Source Code Analysis of Shuffle", Sort Shuffle Writer. // According to the sorting method, the data is sorted and written to the memory buffer. // If the calculation results in the sorting exceed the threshold value, // Overwr ...

Shuffle Output Tracker As an auxiliary component of shuffle, this component plays an important role in the whole shuffle module. In the previous series of analyses, we mentioned this component more or less. For example, when DAGScheduler submits a stage, it encapsulates the stage as a TaskSet, but the possible partitions have been computed and ...

1: Description of processes and threads: Processes: Each process has its own code and data space (process context), and switching between processes can be costly, with 1 to n threads per process.(Process is the smallest unit of resource allocation) Threads: The same type of thread shares code and data space, each thread has its own run stack an ...

From: https://blog.csdn.net/liyanan21/article/details/89320872   Catalog I. Raft algorithm Part of Raft Source Code in Nacos init() 1. Get Raft cluster nodes NamingProxy.getServers() Gets the cluster nodes NamingProxy.refreshSrvIfNeed() Gets node information NamingProxy.refreshServerListFromDisk() Gets cluster node information 2. Raft ...

webpack installation and command line First step initialization (I use Taobao mirror cnpm here) cnpm init Step 2 Install webpack cnpm install webpack --save-dev The third step is to install the loader that handles css cnpm instal css-loader style-loader --save-dev The fourth step is to introduce other files into hello.js, which ...

1. There are four digits: 1, 2, 3 and 4. How many different three digits can be formed without repeating numbers? How much is each?2. The bonus paid by the enterprise shall be deducted on the basis of profit. When the profit is less than or equal to 100,000 yuan, the bonus can be increased by 10%; when the profit is higher than 100,000 yuan, or ...

Linux system is Multi-users and Multi-tasks. The purpose is that a Linux host can provide services to many users and run multiple services at the same time. But how can we distinguish each user? As an administrator, what permissions do I have for Linux systems? As an ordinary user, what can you do with Linux system? This involves the user categ ...

Brief introduction Let's take a hotel as an example. Let's assume that there are only three seats in a hotel. At first, all three seats are empty. At this time, if three guests come at the same time, the waiter allows them to go in for dinner, and then tells the public that there are no seats available. Later guests had to wait at the door unt ...