How to build a server pool

After the computing power of the whole network has been improved to a certain extent, the probability of getting rewards is too low, so that some geeks on "bitcoin talk" can develop a method that can combine a small amount of computing power and operate jointly, and use this method to build websites

in this mechanism, no matter how much computing power an indivial miner can use, as long as he participates in mining activities by joining the mine pool, no matter whether he has successfully mined effective data blocks, he can get a small amount of bitcoin reward through his contribution to the mine pool, that is to say, many people cooperate in mining, and the bitcoin reward is shared by many people according to their contribution

as of January 2019, the top five bitcoin pools in global computing power are btc.com, pool, antpool, flush pool, and f2pool. At present, about 70% of global computing power is in the hands of Chinese miners

extended data:

handling charge:

bitcoin miners will charge a small amount of fees for most transactions, the main purpose of which is to prevent people from sending a large number of boring small transactions and wasting network resources. At present, most of the handling charges for each transaction are & T 3647; 0.0001/kb (0.0001btc / KB). In fact, after 0.9.0, the default handling charge will be reced to & 3647; 0.00001/KB(0.00001 btc/KB)

because the amount of data occupied by most transactions is less than 1 kilobyte, generally speaking, the amount of data is less than 3647; 0.00001 (0.00001 BTC / KB) is enough. At the same time, in the future, when the bitcoin block rewards are less, the service charge will become the main source of miners' income, and the service charge of bitcoin will be related to the number of bytes occupied by the transaction

at present, the calculation standard of service charge in bitcoin system is not mandatory, so users can not give any service charge when the transaction is in progress

however, most miners usually give priority to the transaction with higher handling charges when building data blocks, so that they can get higher remuneration when mining is successful. Therefore, the transaction without any handling charges may take a long time to be processed and incorporated into the blockchain

in addition, e to the block capacity limit of 1MB and the recent increase in bitcoin transaction volume, the handling charges have increased significantly, and the waiting time for the transaction to be confirmed has also become much longer

For self-taught programmers
preface
the first introction to Java technology
Chapter 0 overview of Java technology 1
0.1 Java technology 1
0.1.1 Java programming language 1
0.1.2 Java language platform 2
0.1.3 functions of Java language 2
0.1.4 advantages of Java language 3
0.2 "HelloWorld" application under windows 3
0.2.1 software environment for creating application 3
0.2.2 Step 4 of creating "HelloWorld" application
0.3 discuss "HelloWorld" application 6
0.3.1 annotate source code 6
0.3.2 implement class definition 6
0.3.3 explain main() method 7
0.4 common compilation error 7
0.4.1 environment variable setting error 7
0.4.2 syntax error 7
0.4.3 semantic error 8
0.4 runtime error 8
0.5 exercise 9 in this chapter
Chapter 1 java development tools and environment settings 10
1.1 introction to Java development tools 10
1.2 how to download and install jdk10
1.3 JDK built-in tools 10
1.3.1 JDK common tools 11
1.3.2 JDK common tools example 11
1.3.3 application publishing tool (jar) 12
1.4 creation and viewing of jar files 13
1.4.1 creation of jar files 13
1.4.2 viewing of jar files 15
1.4.2 />1.4.3 extract the contents of jar file 16
1.4.4 update jar file 17
1.4.5 run packaged jar software 19
1.5 JDK environment setting 20
1.6 a simple java application 21
1.7 a simple java applet application 22
1.7.1 write an applet 23
1.7.2 write an HTML file to call applet Java program 23
1.7.3 the running process of applet 23
1.7.3 />1.8 notes and embedded documents 24
1.9 exercise 25
Chapter 2 Java language foundation 26
2.1 Java Naming Rules 26
2.2 data type 26
2.2.1 basic data type 26
2.2.2 reference data type 29
2.3 data type conversion 30
2.3.1 implicit data type conversion 30
2.3.2 explicit data type conversion 30
2.4 variables and constants 31
2.4.1 variables 31
2.4.1 *** Operator 35
2.5.7 operator priority 36
2.6 exercise 36
Chapter 3 program flow control 38
3.1 Process Control Overview 38
3.2 conditional statement 38
3.3 branch statement 39
3.3.1 simple if else statement 39
3.3.2 if else multi branch statement 40
3.3.3 if nested statement 40
3.3.4 switch statement 41
3.3.5 return 42 in branch statement
3.4 Loop statement 42
3.4.1 while loop statement 42
3.4.2 do while loop statement 43
3.4.3 for loop statement 44
3.5 jump statement 45
3.5.1 break jump statement 45
3.5.2 continue jump statement 45
3.6 exercise 46
Chapter 4 array 48
4.1 one dimension group 48
4.1.1 define one dimension array 48
4.1.2 initialize one dimension array 48
4.1.3 use one dimension group 48
4.1.3 Group 49
4.2 2D array 50
4.2.1 define 2D array 50
4.2.2 initialize 2D array 51
4.2.3 use 2D array 51
4.3 multidimensional array 52
4.3.1 define multidimensional array 52
4.3.2 initialize multidimensional array 53
4.3.3 use multidimensional array 54
4.4 number group operation 55
4.4.1 array 55
4.4.2 array filling 55
4.4.3 array comparison 5 6
4.4.4 array sorting 57
4.4.5 array lookup 58
4.5 exercise 60
Chapter 5 string operation 61
5.1 string 61
5.1.1 string classification 61
5.1.2 declaration string 61
5.1.3 creating string 61
5.2 string operation 62
5.2.1 character string connection 63
5.2.2 comparing string 63
5.2.3 obtaining string length 63
5.2.4 ing String 63
5.2.5 get substring 64
5.2.6 get character at specified position 64
5.2.7 change case 65
5.2.8 split string 65
5.2.9 change part of character in string 65
5.3 format string 66
5.3.1 general type format 66
5.3.2 date and time type format 66
5.4 exercise 67
Introction to container class in Chapter 6 68
6.1 container Introction 68
6.1.1 container framework 68
6.1.2 advantages and disadvantages of Java container framework 70
6.2 classification of container interfaces 71
6.2.1collection interface definition and application 71
6.2.2map interface definition and application 73
6.3 set container set75
6.3.1set interface definition and application 75
6.3.2set implementation 77
6.4 list container list81
6.4.1list interface definition and application 81
6.4.2list implementation 83
6.4.3 using list to realize stack and queue 84
6.5map container 86
6.5.1map implementation 86
6.5.2 correctly understanding hashcode method 89
6.6 iterator 91
6.6.1 iterator interface 92
6.6.2 iterator use 92
6.7 exercise 94
Chapter 2 object oriented technology
Chapter 7 introction to object oriented technology
everything is right
7.1 Like 95
7.1.1 abstract understanding in programming 95
7.1.2 how to obtain and manipulate objects 96
7.1.3 object storage 96
7.1.4 object living space 98
7.2 a new data type: class 98
7.2.1 class overview 98
7.2.2 class attribute explanation 99
7.2.3 class method explanation 100
7.2.4 a special method class Constructor 101
7.2.5 keyword static102
7.2.6 keyword this104
7.3 access permission 106
7.3.1 package 106
7.3.2 setting Java access permission 107
7.4 inheritance 110
7.4.1 what is inheritance 110
7.4.2 how to realize inheritance 110
7.4.3super keyword 112
7.5 polymorphism 113
7.5.1 what is polymorphism 113
7.5.2 method overload 114
7.5.1/ >7.5.3 abstract class and abstract function 116
7.6 interface 118
7.6.1 interface definition 118
7.6.2 interface and abstract class 119
7.6.3 interface usage 119
7.7 exercise 122
Chapter 8 object initialization and cleanup 123
8.1 constructor 123
8.1.1 default constructor 124
8.1.2 custom constructor 124
8.2 overload of function 125
8.3 data member Initialization 126
8.4 initialization of static members 128
8.5 object cleaning 132
8.6 exercise 132
Chapter 3 Java programming improvement
Chapter 9 multi thread programming 133
9.1 thread overview 133
9.2 creating thread 134
9.2.1 inheriting thread class creating thread 134
9.2.2 implementing runnable interface creating thread 135
9.3 thread status 136
9.4 thread advantages First level 138
9.5 thread synchronization 139
9.5.1 Java program resource sharing 139
9.5.2 synchronized keyword 141
9.5.3 synchronization control method 142
9.5.4 synchronization control block 144
9.6 thread control 145
9.6.1 start thread 145
9.6.2 suspend and resume thread 146
9.6.3 thread sleep 146
9.6.4 wait and notify 147
9.6.5 end thread 149
9.6.5 9.7 thread communication 150
9.7.1pipedwriter Class 150
9.7.2pipedreader Class 150
9.7.3 pipeline communication instance 151
9.8 multi thread deadlock 153
9.9 multi thread disadvantages 153
9.10 exercise 154
Chapter 10 JDBC link database 155
10.1 JDBC introction 155
10.1.1 what is JDBC 155
10.1.2 JDBC target 155
10.1.3 how to JDBC Realizing the platform independence of database 155
10.2 common classes and interfaces in JDBC 156
10.2.1 driver manager 156
10.2.2 statement 156
10.2.3 database connection 157
10.2.4 resultset 157
10.3 how to realize database link 158
10.3.1 loading appropriate database driver Dynamic program 158
10.3.2 database configuration 158
10.3.3 establish database link and obtain statement object 159
10.3.4 execute database query statement 160
10.3.5 obtain query result 160
10.3.6 close database link 160
10.3.7 complete sample program 160
10.4 basic database operation 162
10.4.1 create database table 162
10.4.2 query data 162
10.4.3 add data 163
10.4.4 change data 163
10.4.5 delete data 163
10.5 exercise 164
Chapter 11 Java exception handling 165
11.1 understand exception 165
11.2 exception examples 165
11.3java exception handling 167
11.3.1try block 167
11.3.2catch block 168
11.3.3java exception specification 171
11.4throwable class and its subclasses 171
11.4.1t Definition and method of hrowable class 172
11.4.2 inheritance relationship of exception class 174
11.4.3 examples of exception replay 174
11.5 runtime exception 177
11.6 custom exception 178
11.7 finally clause 182
11.7.1 necessity of executing finally clause 182
11.7.2 finally clause 184
11.8 several problems of exception 185
11.8.1 exception missing 185
11.8.2 constructor Exception handling 187
11.8.3 exception matching 188
11.9 advantage of exception 189
11.9.1 separate exception handling code 190
11.9.2 propagate error upward according to method calling order 191
11.9.3 group and distinguish error type 193
11.10 exercise 194
Chapter 12 I / O processing 197
12.1 concept of stream 197
12.2 character stream 197
12.2.1 input stream class inputs Tream197
12.2.2 output stream class outputstream198
12.3 byte stream 199
12.3.1 writer class 199
12.3.2 reader class 200
12.4 file class 201
12.4.1 create folder (directory) 201
12.4.2 create file 202
12.4.3 file 203
12.4.4 delete file 204
12.4.5 delete folder 205
12.5i/o stream 207
12.5.1 file stream 207
12.5.2 read memory data 208
12.5.3 link file 209
12.5.4 pipeline flow 210
12.5.5 random access file 211
12.5.6 read 212 from standard input
12.5.7i/o redirection 212
12.5.8 filter flow 213
12.5.9 serialized object 214
12.6 exercise 216
Chapter 13 swing programming 218
13.1swing container 218
13.1.1jframe container 218
13.1.2 JPanel container 219
13.2swing's event model 221
13.2.1 make a button 221
13.2.2 to monitor the event of the button 222
13.2.3swing's event model 223
13.3swing component 224
13.3.1 button 225
13.3.2 icons 225
13.3.3 text 227
13.3.4 tool tip 228
13.3.5 radio button 228
13.3.6 check box 229
13.3.7 group Box 230
13.3.8 list box 232
13.3.9 message box 234
13.3.10 menu 239
13.3.11 tab panel 242
13.3.12 pop up menu 243
13.3.13 toolbar 244
13.3.14 progress bar 246
13.3.15 dialog box 247
13.3.16 file dialog box 248
13.3.17 border 251
13.3.18 table model 252
13.3.19 tree model 255
13.4 control panel layout Manager 261
13.4.1 flow layout manager 261
13.4.2 boundary layout manager 262
13.4.3 grid layout manager 264
13.4.4 box layout manager 266
13.5 exercise 267
Chapter 4 Java distributed computing technology
Chapter 14 Java network programming 269
14.1tcp / ip269
14.1.1ip protocol and IP address 269
14.1.2tcp and port 271
14.1.3 customer /Server communication model 272
14.2udp272
14.3 Java based client / server program 273
14.3.1socket and its primitive 273
14.3.2 create server 274
14.3.3 create client 275
14.4socket class 278
14.4.1 create socket 278
14.4.2socket class getxx() method 280
14.4.3socket class setxx