Mining and loading
Publish: 2021-05-16 21:34:03
1. Of course, it's a miner. You can only buy leeks. Ethereum mining machine is now famous. I recommend Feixun's Ethereum mining machine C8. First of all, C8 reces the mining threshold, eliminates the mining machine's cost, and allows everyone to enter the blockchain. It also saves effort, and does not need to install their own machines. I have bought several, Now I'm in the process of installation and storage. I'll wait for the official excavation. Then I just need to look at the Ethereum wallet every day.
2. Because now many people choose solid-state hard disk to install,
although mining does not need a large capacity storage device, it is not bad to use a small capacity solid-state hard disk, and the whole mining system will run more efficiently.
although mining does not need a large capacity storage device, it is not bad to use a small capacity solid-state hard disk, and the whole mining system will run more efficiently.
3.
First of all, the answer: Linux system has more advantages than windows
The main advantages ofare as follows:
< UL >
operation is relatively more stable and maintenance is more convenient
the cost of system resources is small (that is, the hardware requirements are not high), and the mining cost is saved
the installation and debugging are simple, and the technical threshold is lower
fully open source system, free legal edition, more stable and further save mining cost? In fact, you only need two steps to mine under Linux system:
< UL >open the website, enter the mobile phone number, select how many CPUs you want to use to mine, the default is to use 50% of the CPU to mine, click to generate your exclusive command and
is such a simple operation
4. Sikuai technology has been founded for many years. Its founder is Feng Guodong, an investment enterprise of xiongan fund. At the same time, he is also an engineer of the whole stack, and a technology bull. Blockchain technology plays an increasingly important role in life and work.
5. It's hard to say. It depends on the model of your installed machine, the different model, the different miner manufacturer, the different size of miner and the different refrigeration equipment. The number of miners installed is different. You can ask a professional big miner about this. There are more mines deployed in Inner Mongolia, because the rent and electricity price are very low there.
6. Mining is divided into underground mining, open-pit mining, melting mining, deep-sea mining, and various equipment used are also different. Take the most common open-pit and underground mining for example
open pit mining mainly involves large-scale excavation, down the hole drill, cone drill, front loader, mining truck (with loading capacity ranging from several tons to tens of tons or even hundreds of tons), and explosive transportation vehicles. Listen to the hard stories of celebrities
according to different mining methods, underground mining mainly includes: ① hoist, ② fan (it is divided into axial flow fan and cyclone according to specific conditions), ③ drainage pump and ④ air compressor, which are the main equipment and the biggest energy consumption of the mine
other equipments include rock drilling jumbo, various rock drills, local fans and tramcars according to mining needs. Rock loader, electric rake, crusher, electric locomotive, cage (skip), etc
when it comes to site selection and smelting, it is a set of more complex equipment, such as flotation machine, ball mill, rod mill, etc.
open pit mining mainly involves large-scale excavation, down the hole drill, cone drill, front loader, mining truck (with loading capacity ranging from several tons to tens of tons or even hundreds of tons), and explosive transportation vehicles. Listen to the hard stories of celebrities
according to different mining methods, underground mining mainly includes: ① hoist, ② fan (it is divided into axial flow fan and cyclone according to specific conditions), ③ drainage pump and ④ air compressor, which are the main equipment and the biggest energy consumption of the mine
other equipments include rock drilling jumbo, various rock drills, local fans and tramcars according to mining needs. Rock loader, electric rake, crusher, electric locomotive, cage (skip), etc
when it comes to site selection and smelting, it is a set of more complex equipment, such as flotation machine, ball mill, rod mill, etc.
7. According to Blizzard's setting, Warcraft uses five farmers to collect gold, and more than five will be idle population
hope to adopt
hope to adopt
8.
package main
import "fmt"
func main() {
var a interface{}
var b string
a = "asdasdasdasd"
b = a.(string)
fmt.Println(a, b)
9. ① Open the previously prepared form, and directly enter in cell A2: = & quot; A"& TEXT(ROW()-1," 00000") The meaning of the formula will be introced later
press enter to get the result a00001, which is obtained by formula instead of manual input
③ move the mouse to the lower right corner of the cell, and the + sign will appear. Double click to complete the filling. Because all the data is calculated according to the formula, it is only related to changing the line. Deleting another line will not affect itself
formula meaning
text (numeric value, cell format): converts a numeric value to a text in a specified number format
row(): returns the row number of the cell
first, use row () - 1 to return 1, then use the text function to set 1 to 00001, and finally concatenate a with 00001.
press enter to get the result a00001, which is obtained by formula instead of manual input
③ move the mouse to the lower right corner of the cell, and the + sign will appear. Double click to complete the filling. Because all the data is calculated according to the formula, it is only related to changing the line. Deleting another line will not affect itself
formula meaning
text (numeric value, cell format): converts a numeric value to a text in a specified number format
row(): returns the row number of the cell
first, use row () - 1 to return 1, then use the text function to set 1 to 00001, and finally concatenate a with 00001.
10. What is LDAP
the full English name of LDAP is lightweight directory access protocol, which is generally referred to as LDAP. It is based on the X.500 standard,
but it is much simpler and can be customized according to needs. Unlike X.500, LDAP supports TCP / IP, which is necessary to access the Internet. The core specification of LDAP
is defined in RFC, and all RFCs related to LDAP can be found in ldapman RFC web page. Now LDAP technology is not only developing rapidly, but also exciting. Implementation of LDAP in the enterprise can make all applications running on almost all computer platforms get information from LDAP directory. LDAP directory can store various types of data: e-mail address, e-mail routing information, human resource data, public key, contact list, etc. By taking LDAP directory as an important part of system integration, it can simplify the steps for employees to
query information within the enterprise, and even the main data sources can be placed anywhere
advantages of LDAP directory
if it is necessary to develop a system to provide public information query, the general design method may be based on Web database design, that is, the front-end
uses browser, and the back-end uses web server and relational database. The typical implementation of back end in windows may be Windows NT + IIS + ACESS
database or SQL server. IIS and database are connected through ASP technology using ODBC to achieve the function of querying data by filling in forms
the typical implementation of back-end in Linux system may be Linux + Apache + PostgreSQL. Apache and database are connected through the functions provided by PHP3. The disadvantage of using the above method is that the introction of back-end relational database leads to the performance degradation of the system as a whole and the management of the system is cumbersome, because it needs to verify the data type and the integrity of the transaction continuously; In addition, the front-end user's control of data is not flexible enough. Generally, the user's permissions can only be set at the table level, not at the record level
the introction of directory service is mainly to solve the problems existing in the above databases. Similar to relational database, directory refers to a descriptive set of records based on attributes, but its data type is mainly character type. In order to search, syntax (Syntax) such as bin (binary data), CIS (ignore case), CES
(case sensitive), Tel (telephone type) is added instead of integer, floating-point number, etc. provided by relational database For date, currency and other types,
also does not provide a large number of functions, such as those commonly used in relational databases. It is mainly oriented to data query service (query and modification operation ratio is generally greater than
10:1), and does not provide transaction rollback mechanism. Its data modification uses a simple locking mechanism to achieve all or nothing, Its goal
is fast response and large capacity query, and provides information replication function of multi directory server
now it's time to talk about the advantages of LDAP directory. The popularity of LDAP is the result of many factors. Perhaps the biggest advantage of LDAP is that it can access LDAP directory on any computer platform with an increasing number of easily available LDAP client programs. And it's easy to
customize the application and add LDAP support to it
LDAP protocol is a cross platform and standard protocol, so applications don't have to worry about what kind of server the LDAP directory is placed on. In fact, LDAP
is widely accepted by the instry because it is the standard of Internet. Manufacturers are willing to add LDAP support to their procts, because they don't need to
consider what the other end (client or server) is like. LDAP server can be any source code developed or commercial LDAP directory server (or a relational database with LDAP interface) because it can interact with LDAP server with the same protocol, client connection software package and query command. Different from LDAP, if software manufacturers want to integrate DBMS support in software procts, they usually need to customize each database service
server separately. Unlike many commercial relational databases, you don't have to pay for every LDAP client connection or license agreement. Most LDAP servers are easy to install, maintain and optimize<
the LDAP server can part or all of the data by "push" or "pull", for example, it can "push" the data to the remote office to increase the security of
data. Replication technology is built into the LDAP server and is easy to configure. If you want to use the same replication function in a DBMS, the database
manufacturer will charge you extra and it is difficult to manage
LDAP allows you to use ACI (commonly known as ACL or access control list) to control the read and write permissions of data as needed. For example, the device administrator can
change the employee's work location and office number, but it is not allowed to change other fields in the record. Aci can control the access of data according to who accesses the data, what number of data to access, where the data exists and others. Because these are all done by the LDAP directory server, there is no need to worry about whether to check the security of the client application
LDAP (Lightweight Directory acess protocol) is the implementation of directory service over TCP / IP (RFC 1777 V2 and RFC 2251
V3). It is a porting of X500 directory protocol, but it simplifies the implementation method, so it is called lightweight directory service. In LDAP, the directory is organized according to the tree structure. The directory is composed of entries, which are equivalent to the records of tables in relational database; An entry is a set of attributes with distinguished
name (DN), which is equivalent to the keyword (primary
key) in the relational database table; Attribute is composed of type and values, which is equivalent to that the field in relational database is composed of domain name and data type,
just for the convenience of retrieval, the type in LDAP can have multiple values, instead of each
field that is required to be implemented in relational database to rece the rendancy of data. The organization of entries in LDAP is usually organized according to geographical location and organizational relationship, which is very intuitive. LDAP stores data in
files. To improve efficiency, we can use index based file database instead of relational database. LDAP protocol set also specifies DN naming method, storage
access control method, search format, method, URL format, development interface, etc.
LDAP is most useful for storing such information, that is, data needs to be read from different places, but it does not need to be updated frequently
for example, it is very effective to store these information in the LDAP directory:
l telephone directory and organization chart of company employees
L contact information of customers
l information needed for computer management, including NIS mapping, email pseudonym, And so on
L software package configuration information
L public certificate and security key
when to use LDAP to store data
most LDAP servers are specially optimized for read intensive operations. Therefore, when reading data from LDAP server, it will be one order of magnitude faster than reading data from relational database optimized for
OLTP. Most LDAP directory servers are not suitable for storing data that needs to be changed frequently. For example, using LDAP server to store phone numbers is a good choice, but it can't be used as a database server for
e-commerce sites
if the answer to each of the following questions is "yes", it is a good idea to store the data in LDAP
l do you need to be able to read data on any platform
L does each indivial record item change very little every day
l can data be stored in flat database instead of relational database? In other words, no matter what paradigms are not
paradigms, put everything in a record (almost as long as the first paradigm is satisfied)
the last question may frighten some people. In fact, it is very common to use flat database to store some relational data. For example, a company employee
record can contain the manager's login name. It is convenient to store this kind of information with LDAP. A simple way to judge: if you can store the data
in one card after another, you can easily store it in the LDAP directory
Security and access control
LDAP provides very complex access control or ACI at different levels. Because these accesses can be controlled on the server side, it is much safer than using the client software to ensure the
security of data<
with ACI of LDAP, users can change their own phone number and home address, but they are limited to read-only access to other data (such as job name, manager login,
etc.)
L "HR admins & quot; Everyone in the group has permission to change the information of the following users: manager, job name, employee number, department name and department number
but no write permission to other domains
L no one is allowed to query the user password on the LDAP server, but the user can be allowed to change his or her own password
l give managers read-only access to their superior's home phone, but forbid other people to have this access
L "host admins & quot; Anyone in the group can create, delete and edit all the information related to the computer host stored in the LDAP server
L through the web, allowing "foobar Sales & quot; Members of the group selectively grant or prohibit themselves from reading part of customer contact data. This
will allow them to download customer contact information to their local laptop or personal digital assistant (PDA) If the salesperson's software supports LDAP,
this will be very useful)
L through the web, group owners are allowed to delete or add members of their own groups. For example, you can allow the sales manager to give or prohibit the sales staff from changing the web
page permissions. You can also allow the owner of the email alias to delete or add users directly from the email alias without going through it technicians
"public" mailing lists should allow users to add or remove themselves (but only themselves) from their pseudonyms. The IP address or host name can also be
restricted. For example, some domains only allow users with IP addresses beginning with 192.168.200 * to have read permission, or use
the full English name of LDAP is lightweight directory access protocol, which is generally referred to as LDAP. It is based on the X.500 standard,
but it is much simpler and can be customized according to needs. Unlike X.500, LDAP supports TCP / IP, which is necessary to access the Internet. The core specification of LDAP
is defined in RFC, and all RFCs related to LDAP can be found in ldapman RFC web page. Now LDAP technology is not only developing rapidly, but also exciting. Implementation of LDAP in the enterprise can make all applications running on almost all computer platforms get information from LDAP directory. LDAP directory can store various types of data: e-mail address, e-mail routing information, human resource data, public key, contact list, etc. By taking LDAP directory as an important part of system integration, it can simplify the steps for employees to
query information within the enterprise, and even the main data sources can be placed anywhere
advantages of LDAP directory
if it is necessary to develop a system to provide public information query, the general design method may be based on Web database design, that is, the front-end
uses browser, and the back-end uses web server and relational database. The typical implementation of back end in windows may be Windows NT + IIS + ACESS
database or SQL server. IIS and database are connected through ASP technology using ODBC to achieve the function of querying data by filling in forms
the typical implementation of back-end in Linux system may be Linux + Apache + PostgreSQL. Apache and database are connected through the functions provided by PHP3. The disadvantage of using the above method is that the introction of back-end relational database leads to the performance degradation of the system as a whole and the management of the system is cumbersome, because it needs to verify the data type and the integrity of the transaction continuously; In addition, the front-end user's control of data is not flexible enough. Generally, the user's permissions can only be set at the table level, not at the record level
the introction of directory service is mainly to solve the problems existing in the above databases. Similar to relational database, directory refers to a descriptive set of records based on attributes, but its data type is mainly character type. In order to search, syntax (Syntax) such as bin (binary data), CIS (ignore case), CES
(case sensitive), Tel (telephone type) is added instead of integer, floating-point number, etc. provided by relational database For date, currency and other types,
also does not provide a large number of functions, such as those commonly used in relational databases. It is mainly oriented to data query service (query and modification operation ratio is generally greater than
10:1), and does not provide transaction rollback mechanism. Its data modification uses a simple locking mechanism to achieve all or nothing, Its goal
is fast response and large capacity query, and provides information replication function of multi directory server
now it's time to talk about the advantages of LDAP directory. The popularity of LDAP is the result of many factors. Perhaps the biggest advantage of LDAP is that it can access LDAP directory on any computer platform with an increasing number of easily available LDAP client programs. And it's easy to
customize the application and add LDAP support to it
LDAP protocol is a cross platform and standard protocol, so applications don't have to worry about what kind of server the LDAP directory is placed on. In fact, LDAP
is widely accepted by the instry because it is the standard of Internet. Manufacturers are willing to add LDAP support to their procts, because they don't need to
consider what the other end (client or server) is like. LDAP server can be any source code developed or commercial LDAP directory server (or a relational database with LDAP interface) because it can interact with LDAP server with the same protocol, client connection software package and query command. Different from LDAP, if software manufacturers want to integrate DBMS support in software procts, they usually need to customize each database service
server separately. Unlike many commercial relational databases, you don't have to pay for every LDAP client connection or license agreement. Most LDAP servers are easy to install, maintain and optimize<
the LDAP server can part or all of the data by "push" or "pull", for example, it can "push" the data to the remote office to increase the security of
data. Replication technology is built into the LDAP server and is easy to configure. If you want to use the same replication function in a DBMS, the database
manufacturer will charge you extra and it is difficult to manage
LDAP allows you to use ACI (commonly known as ACL or access control list) to control the read and write permissions of data as needed. For example, the device administrator can
change the employee's work location and office number, but it is not allowed to change other fields in the record. Aci can control the access of data according to who accesses the data, what number of data to access, where the data exists and others. Because these are all done by the LDAP directory server, there is no need to worry about whether to check the security of the client application
LDAP (Lightweight Directory acess protocol) is the implementation of directory service over TCP / IP (RFC 1777 V2 and RFC 2251
V3). It is a porting of X500 directory protocol, but it simplifies the implementation method, so it is called lightweight directory service. In LDAP, the directory is organized according to the tree structure. The directory is composed of entries, which are equivalent to the records of tables in relational database; An entry is a set of attributes with distinguished
name (DN), which is equivalent to the keyword (primary
key) in the relational database table; Attribute is composed of type and values, which is equivalent to that the field in relational database is composed of domain name and data type,
just for the convenience of retrieval, the type in LDAP can have multiple values, instead of each
field that is required to be implemented in relational database to rece the rendancy of data. The organization of entries in LDAP is usually organized according to geographical location and organizational relationship, which is very intuitive. LDAP stores data in
files. To improve efficiency, we can use index based file database instead of relational database. LDAP protocol set also specifies DN naming method, storage
access control method, search format, method, URL format, development interface, etc.
LDAP is most useful for storing such information, that is, data needs to be read from different places, but it does not need to be updated frequently
for example, it is very effective to store these information in the LDAP directory:
l telephone directory and organization chart of company employees
L contact information of customers
l information needed for computer management, including NIS mapping, email pseudonym, And so on
L software package configuration information
L public certificate and security key
when to use LDAP to store data
most LDAP servers are specially optimized for read intensive operations. Therefore, when reading data from LDAP server, it will be one order of magnitude faster than reading data from relational database optimized for
OLTP. Most LDAP directory servers are not suitable for storing data that needs to be changed frequently. For example, using LDAP server to store phone numbers is a good choice, but it can't be used as a database server for
e-commerce sites
if the answer to each of the following questions is "yes", it is a good idea to store the data in LDAP
l do you need to be able to read data on any platform
L does each indivial record item change very little every day
l can data be stored in flat database instead of relational database? In other words, no matter what paradigms are not
paradigms, put everything in a record (almost as long as the first paradigm is satisfied)
the last question may frighten some people. In fact, it is very common to use flat database to store some relational data. For example, a company employee
record can contain the manager's login name. It is convenient to store this kind of information with LDAP. A simple way to judge: if you can store the data
in one card after another, you can easily store it in the LDAP directory
Security and access control
LDAP provides very complex access control or ACI at different levels. Because these accesses can be controlled on the server side, it is much safer than using the client software to ensure the
security of data<
with ACI of LDAP, users can change their own phone number and home address, but they are limited to read-only access to other data (such as job name, manager login,
etc.)
L "HR admins & quot; Everyone in the group has permission to change the information of the following users: manager, job name, employee number, department name and department number
but no write permission to other domains
L no one is allowed to query the user password on the LDAP server, but the user can be allowed to change his or her own password
l give managers read-only access to their superior's home phone, but forbid other people to have this access
L "host admins & quot; Anyone in the group can create, delete and edit all the information related to the computer host stored in the LDAP server
L through the web, allowing "foobar Sales & quot; Members of the group selectively grant or prohibit themselves from reading part of customer contact data. This
will allow them to download customer contact information to their local laptop or personal digital assistant (PDA) If the salesperson's software supports LDAP,
this will be very useful)
L through the web, group owners are allowed to delete or add members of their own groups. For example, you can allow the sales manager to give or prohibit the sales staff from changing the web
page permissions. You can also allow the owner of the email alias to delete or add users directly from the email alias without going through it technicians
"public" mailing lists should allow users to add or remove themselves (but only themselves) from their pseudonyms. The IP address or host name can also be
restricted. For example, some domains only allow users with IP addresses beginning with 192.168.200 * to have read permission, or use
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