[oracle@hellow ~]$ lsnrctl start
LSNRCTL for Linux: Version 12.1.0.2.0 – Production on 04-Nov-2021 15:30:14
Copyright © 1991, 2014, Oracle. All rights reserved.
TNS-01106: Listener using listener name LISTENER has already been started
– The ps command did not find the listening process
[root@sh ~]# ps -ef | grep -i tns
root 36 2 0 Jan26 ?00:00:00 [netns]
root 14995 14824 0 15:30 pts/1 00:00:00 grep -i tns
– Check the listening status, error reported; TNS-01189
[oracle@sh ~]$ lsnrctl status
LSNRCTL for Linux: Version 12.1.0.2.0 – Production on 4-NOV-2021 15:57:39
Copyright © 1991, 2014, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=hello)(PORT=1521)))
TNS-01189: The listener could not authenticate the user
– There are basically 2 reasons for this problem,
1, the ip and hostname in /etc/hosts file are not the same
2, the listener.ora listener host is not the current host.
After checking, the listener.ora listener host is incorrectly filled in
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = hellow)(PORT = 1521))
)
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
)
)
After changing to the current host name, restart the listener to resume normal.
Tag Archives: database
[Solved] Redis Error: Unexpected exception while processing command
1. Background
Redis has been running for a long time, and an error is reported one day as follows:
2. Phenomenon
org.redisson.client.RedisException: Unexpected exception while processing command
at org.redisson.command.CommandAsyncService.convertException(CommandAsyncService.java:338)
at org.redisson.command.CommandAsyncService.get(CommandAsyncService.java:140)
at org.redisson.RedissonObject.get(RedissonObject.java:90)
at org.redisson.RedissonBucket.set(RedissonBucket.java:131)
3. Solution
Restart the Java application!
What exactly caused it,
You can only guess the link pool of the redis client. Due to network and other reasons, the redis client has not responded for a long time and collapsed!
perfect
Solution to the error of ODBC driver in windows installation of Postgres database
Solution to the error of ODBC driver in windows installation of Postgres database
Installing postgressql driver on Windows reports an error “the specified module cannot be found”
terms of settlement
Find another system of the same version, which can install the modified drive computer normally. Paste the contents of the two folders in the windows folder of drive C into the system that cannot be installed
copy the two folders in the above figure to the problem computer. Select duplicate files, ignore them, and do not select replacement, so as not to affect the use of the system
Solutions to errors in the final running of JDBC programming
An error is reported at the end of JDBC programming:
Exception in thread “main“ java.sql.SQLException: Unknown initial character set index ‘255‘ received
resolvent:
When establishing a connection between JDBC and the database, add the following after the URL:
?useUnicode=true&characterEncoding=utf-8
As shown in the figure: 
Add reason:
Mysql database uses GBK coding, while the project database uses UTF-8 coding.
An error occurs when pymysql uses% d to pass in parameters
Error:
When using pymysql, an error occurs when using% d to pass parameters in the SQL statement. As shown in the figure: 
Error information: typeerror:% d format: a number is required, not str
Cause of problem:
When a parameter of type int is passed in, it is converted to a parameter of type str. Therefore, the solution is to change% d into% s, pass in int type, and it can still be executed.
Modified: 
Data of type int passed in:
Can execute successfully
Solution:
When data of type int is passed in, the parameter is still passed with% s.
Error report of mongodb startup under Linux
Version:MongoDB 5.0.3
1. Use the configuration file to start the error 1:
View log:
The reason is an error in the configuration file:
#mongod.conf
net:
bindIp: localhost,172.20.10.9 # 172.20.10.9 LAN IP for host computer
After 172.20.10.9 of bindip is deleted, it can be started successfully, but the host cannot connect to mongodb. At this time, by changing bindip to bindipall: true, it means that all IPS are allowed to connect to this mongodb
If you want to configure multiple IP addresses but do not want all IP addresses to be accessible, the above instructions are used, and the partition cannot be started. Query the network and learn that it is configured through [IP1, IP2], and the result is also an error:
Conclusion: If it is only accessed locally, you can configure localhost in bindip,
If other IPS want to access, they can only configure bindip: 0.0.0.0 or bindipall: true
2. Use the configuration file to start error 2:
Problem cause: caused by abnormal shutdown
Solution: delete the. Lock file under the data directory, and then specify the data directory to start by — dbpaht or add the — repair parameter. After successful startup, start it by using the configuration file method
3. Add in replica set No response when arbitrating nodes
Problem: by executing the shell in the master node, rs.addarb (host: port) does not respond, and the arbitration node cannot be added. At this time, the version is 5.0.3
Solution: reduce the version to 4.0.1
[Solved] Mybatis.generator error: Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2
Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate (default-cli) on project pas-service-devops: Execution default-cli of goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate failed: Plugin org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2 or one of its dependencies could not be resolved: Failure to find com.oracle:ojdbc14:jar:10.2.0.3 in http://maven.aliyun.com/nexus/content/repositories/central/ was cached in the local repository, resolution will not be reattempted until the update interval of alimaven has elapsed or updates are forced
maven dependency did not enter
Re-select dependency version :14 before, change to 8
<dependency>
<groupId>com.oracle.database.jdbc</groupId>
<artifactId>ojdbc8</artifactId>
<version>21.1.0.0</version>
</dependency>
<dependency>
<groupId>cn.easyproject</groupId>
<artifactId>orai18n</artifactId>
<version>12.1.0.2.0</version>
</dependency>
The MAC system installs MySQL client, and the error is solved_ config not found
The MAC system installs MySQL client, and the error is solved_ config not found
Using PIP3 install MySQL_ Client error
The error message is as follows: prompt: oserror: MySQL_ config not found
python setup.py egg_ info Check the logs for full command output
mysql_ Config not found
Solve the problem according to the error report
Prompt that the file does not exist. Use find to find the file and verify whether the file exists
find/- name MySQL_ Config
you can see that the file exists. It is preliminarily judged that the environment variable 
is not configured
resolvent
Add the queried address to the environment variable
export path = $path:/usr/local/mysql-5.6.38-macos10.12-x86_ 64/bin
Verify again
Download again, the prompt is successful, and the problem is solved 
Problem regression
Because MySQL has been downloaded before, the environment variable configuration may be deleted when operating other contents. This method is not applicable to all cases
Insert datagram error: ISAM error: no free disk space
I made a mistake in migrating data times:
[error]: error inserting data
Error SQLCode：[-271]
Error message:Could not insert new row into the table:(-271) ISAM error:no free disk space(-131)
After checking the storage space, it is found that the space is free. After inquiry, it is found that the database built by Informix will often report an error when importing a large amount of data.
You can search for settings about Informix’s extend size and next size.
How Informix determines the extent size and next size_ The growth of database technology… – CSDN blog
Then my solution is as like as two peas: i migrated data, so I set up a table structure that is exactly the same as the database to be migrated in the destination database, but the value of extent size and next size is needed to build the table statement. For example, if I want to migrate a 34 g table, set the value of my extent size to 33554430 (the default unit is KB, which is the maximum value, 32g) and the next size to 1048576 (1 g or 2 g). Of course, the table space is extensible.
Create table table name（
id CHAR（64），
age INTEGER
）
extent size 33554430 next size 1048576;
In tablespace name;
The values of ext size and next size are about the same as the data size, because my table space is extensible. If it is not extensible, it is better to be larger than the data size.
[PostgreSQL tutorial] · PostgreSQL error prompt: “error 42501” or “permission denied”
Article catalog
1. Problem overview 2. Solution
1. Problem overview
log in to the PostgreSQL database service with the PSQL command. When querying data, you receive an error log prompt, as follows:
“Error 42501” or “Permission Denied”
2. Solution
PostgreSQL error code 42501 is a common error, which sometimes occurs when responding to PostgreSQL database queries. In most cases, the error code 42501 indicates that the user has insufficient permissions on the database. PostgreSQL responds with an error message whenever a user with insufficient permissions makes a query
to solve this problem, please check the database user permissions. If the user trying to query lacks permission, just change the permission accordingly. You can use “ grant select on table_name to public; ” to grant permission to the public. Or use the command “ grant select on table_name to user_name; ” for only a few users
An error is reported when kettle connects Oracle database and MySQL database
1. An error is reported when kettle connects to Oracle database
When kettle connects to Oracle database for the first time, it reports an error “wrong connection to database [Oracle] ”， This is because spoon lacks the jar package corresponding to Oracle. If Oracle or Oracle client is installed, you can copy the corresponding jar file from their installation directory to solve the error problem.
Solution:
Copy and paste all files starting with ojdbc in Oracle database, such as ojdbc5 and ojdbc6.jar, into the spoon directory, such as D: \ kettle \ data-integration-8.2.0.7-719 \ lib\ Just under the path.
2. An error is reported when kettle connects to MySQL database
The error contents are as follows:
This is caused by the missing jar connection package of MySQL.
Solution:
You need the jar connection package of MySQL database, such as mysql-connector-java-8.0.11.jar, copy and paste it into the spoon directory, such as D: \ kettle \ data-integration-8.2.0.7-719 \ lib\ Just under the path.
The attachment download link is as follows:
Kettle driver. TXT other document resources CSDN Download
[PostgreSQL tutorial] · out of memory issue
Article catalog
1. Problem description 2. Solution
1. Problem description
the PostgreSQL server running on the server receives an error log prompt message:
ERROR: out of memory 2021-11-24
DETAIL: Failed on request of size 1880.
2. Solution
the memory of each system is limited. When there is no memory left, PostgreSQL’s memory allocation function begins to fail. Please check your hardware configuration and limitations