Network design for network engineering data communication training (HCIA comprehensive experiment: communication between company intranet, external network, and personal network)

Experimental environment requirements: Huawei ensp, virtualbox are as follows: Experimental topology: Terminal naming method: Routers are devices that start with R, and switches are devices that start with S. For example: The corresponding name of AR1 is: R1 The corresponding name of LSW2 is: S2 I. Exchange part 1.S1, R1 interconnection link set up LACP […]

The datetime type in el-date-picker disables dates containing time and minutes

It’s a very confusing situation. For the disabled time under the datetime type, the timestamp is disabled in pickerOptions, but the time division cannot be disabled. Idea: disabledDate in pickerOptions disables overall date selection Disable time range through selectableRange Disadvantage: still cannot disable the second range // view interface <el-date-picker v-model=”remindTime” type=”datetime” placeholder=”Select time” value-format=”timestamp” […]

python self (2) slice dictionary traverse delete add modify query definition function function return value scope serialization exception error urllib uses one type and six methods to download video audio picture

Slice # # Slice # s = ‘hello word’ # # The subscript index is 0 # print(s[0]) #h # # Left closed and right open (left starts with the subscript, right is several index values), for example, 4 index values starting from 0 # print(s[0:4]) #hell # # Change the starting position of the […]

C language internal skill training—detailed explanation of pointers (beginner level)

Foreword: They say that it only takes a few weeks to speak a language. I disagree with this statement, at least not after I learned C language pointers. Do not believe? Come show your talents: //Code 1 (*(void (*)())0)(); //Code 2 void (*signal(int , void(*)(int)))(int); These two lines of code are from “C Pitfalls and […]

PostgreSQL Data Definition Language DDL

Article directory Table creation primary key constraints non empty unique constraint Check constraints foreign key constraints Default value constraints trigger table space Build tablespace view index Basic concepts of indexing Index classification Create index materialized view Table creation The construction statement of the PostgreSQL table is the same as that of all databases. The structure […]

JUC concurrent programming – Join method analysis: Why does calling the Join method of the sub-thread in the main thread cause the main thread to block instead of the sub-thread? (I haven’t finished writing, I don’t want to write anymore)

1. Example code public class JoinTest { public static void main(String[] args) throws Exception { String start = nowTime(); System.out.println(start + “–>” + Thread.currentThread().getName() + ” end!”); Thread threadA = new Thread(new JoinThread(2), “A”); Thread threadB = new Thread(new JoinThread(5), “B”); Thread threadC = new Thread(new JoinThread(5), “C”); threadA.start(); threadB.start(); threadC.start(); threadA.join(); String end = […]

Youth Training Camp-Spark Principles and Practice

5.1 Introduction to Spark, the big data processing engine 1. Big data processing technology stack 2. Common big data processing links 3. Open source big data processing engine 4.What is Spark? Official website: 5.Spark version evolution 6.Spark ecology and features 1) Unified engine supports multiple distributed scenarios 2) Multi-language support 3) Readable and writable rich […]