statusRndc:connect Failed:127.0.0.1#953:connection refusedNamed dead but Subsys lockedTwo: Configure server side to use RNDC control client[Email protected] etc]# rndc-confgen |grep-v ' ^# '//as before to generate new Rndc.key and rndc.confKey "Rndckey" {Algorithm HMAC-MD5;Secret "p3dukvxgufspbzdavzy1ya==";};Options {Default-key "Rndckey";Default-client 127.0.0.
DNS Service/etc/rndc. key was found solution after the dns service is configured in RHEL6, the following problems may occur. rndc cannot find the key, and the named service runs normally. In fact, it can also be used, however, based on the principle that one problem cannot be spared, the solution [root @ server named] #/etc/init. d/named statusrndc: neither/etc/rndc
First two BIND DNS servers to function correctly.Primary DNS server ip:192.168.1.100Client DNS server ip:192.168.1.1011 Primary DNS-side configuration:cd/etc/Generate Rndc.conf FileRndc-confgen > rndc.confView FilesCat rndc.conf# Start of Rndc.confKey "Rndc-key" {Algorithm HMAC-MD5;Secret "vcl5wc2ghczcu7ju+ajc1q==";};Options {Default-key "Rndc-key";Default-server 127.0.0.1;Default-port 953;};# End of Rndc.c
RNDC: Remote Control DNS Server[[email protected] ~]# vim randomThere is no random generator on the server, manually forge a file instead of the/dev/random function create a new random file and enter a string of numbers, remember to longVim RandomAsdkfjalsjdflajsldfjlasjdflajsldfjalsjdflajslfjalsjflasjfl[Email protected] ~]# Rndc-confgen >/etc/rndc.conf[[email protected] ~]#
rndc-Instructions for useRNDC Settings (local)Produce/etc/rndc.keyAfter executing the "rndc-confgen-a" command, the Rndc.key file is generated in the/etc directory,The resulting file contents are as follows:"Algorithm Hmac-md5" means that we use the "HMAC-MD5" algorithm to generateEach execution of "secret" produces a different "secret".Generate/etc/rndc.conf File1. After executing the instruction, the rndc
After passing the zone file through rsync. Need to direct RNDC from DNS so ... I can write a script to finish it at once. It's convenient.
There are several conditions to remotely RNDC DNS
First: In the name.conf on the server to be controlled by RNDC, you must write this:
Controls {inet 192.168.1.241 Port 953Allow {127.0.0.1;192.168.1.243} keys {"
Left JOIN and right connections:Left JOIN: The query is based on left table, the left table data are all displayed, the right table shows all the data matching the left table, the mismatch is shown as nullRight connection (opposite to left join): the right table as the benchmark for the query, the right table data are all displayed, the left table and the right table matches the data are all displayed, the mismatch is displayed as nullFull
Recently, the company is recruiting people. My colleagues asked a few questions about database connection that I think the database can be applied ~
Now I want to write about their functions here.
Assume that the following table is used:
One is the voting master table, and the other is the voter information table ~ Record the IP address of the voter and the corresponding voting type. The left-right connection
PrefaceThe connection types are divided into three categories: inner connection , outer connection , Cross connection . Inner joins use the INNER join keyword, INNER join matches a common value in two tables, and only rows that meet the join condition are used to build the result set, INNER Join is the default join
, teacher) (4, principal)Internal connection results:Select a.*,b.* from A inner join B on a.id=b.id;1 31 students2 Li 42 TeacherLeft JOIN Connection results:Select a.*,b.* from A left join B on A.id=b.id;1 31 students2 Li 42 Teacher3 Harry NULL NULLRight Join Result:Select a.*,b.* from A right join B on a.id=b.id;1 31 students2 Li 42 TeacherNull NULL 4 PrincipalFull connectivity ResultsSelect a.*,b.* from
Four Oracle connections: left outer connection, right outer connection, inner connection, and full connection. Right outer connection of oracle
Today, when looking at a data table of a legacy system, we found that the view we usually look for is full out join. As a result,
1. Inner Connection(A typical join operation, using a comparison operator like = or Inner joins use comparison operators to match rows in two tables based on the values of the columns that are common to each table. For example, retrieve all lines of the students and courses table with the same student identification number.2, outer joins. An outer join can be a left outer join, a right outer join, or a full outer join.When you specify an outer join in
Tags: external connection customer cross join NULL Value Table association test implement Union constraint1. Inner Connection(A typical join operation, using a comparison operator like = or Inner joins use comparison operators to match rows in two tables based on the values of the columns that are common to each table. For example, retrieve all lines of the students and courses table with the same student i
1. Inner Connection(A typical join operation, using a comparison operator like = or Inner joins use comparison operators to match rows in two tables based on the values of the columns that are common to each table. For example, retrieve all lines of the students and courses table with the same student identification number.2, outer joins. An outer join can be a left outer join, a right outer join, or a full outer join.When you specify an outer join in
1. Inner Connection(A typical join operation, using a comparison operator like = or 2, outer joins. An outer join can be a left outer join, a right outer join, or a full outer join. When you specify an outer join in the FROM clause, you can specify it by one of the following sets of keywords:1) Left JOIN or left OUTER joinThe result set of the left outer join includes all rows of the left table specified in the outer clause, not just the rows that mat
Tags: blog http using OS data ar problem divSQL joins the join cases Urealyticum. (left connection, right connection, full connection, inner connection, cross connection, self-connection) recently the company is hiring, colleagues
Tags: Connection Method field name comparison field record right outer connection outer JOIN mode use 1-- inner connection: INNER JOIN It represents a matching record that returns two tables or Recordset join fields, representing the portions
of the two tables that are contained in each other 2 Select * from Inner Join On Student.sno= sc.sno; 3 -- outer j
Label:The join condition can be specified in the From or WHERE clause, and it is recommended that the join condition be specified in the FROM clause. The WHERE and having clauses can also contain search criteria to further filter the rows selected by the join condition.Connections can be divided into the following categories:internal connections. (typical join operation, using a comparison operator like = or equal connections and natural connections . An inner join uses a comparison operator to
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