The authentication problem occurs because redis has set the authentication password
after startup, enter the following command:
127.0.0.1:6379> auth yourpassword
My password is redis123
127.0.0.1:6379> set name hello
(error) NOAUTH Authentication required.
127.0.0.1:6379> (error) NOAUTH Authentication required.
(error) ERR unknown command '(error)'
127.0.0.1:6379> auth redis123
ok
Redis can be operated normally.
When we set up redis master-slave replication, we may encounter the following problems due to various problems:
error condition on socket for Sync: no route to host
Solution:
First, modify the related configurations in redis.conf:
#Original configuration
bind 127.0.0.1
#Modify to
bind 0.0.0.0
# Although it is said that commenting it out can also solve the above problem, it is not recommended to comment out this method. Because another problem will occur.
#or comment it out
#bind 127.0.0.1
Turn off the firewall of the host. Note: it is the firewall of the host, and then restart the service.
In CentOS 7, systemctl stop firewalld turns off the firewall. Other versions can turn off the firewall through service iptables stop.
Turn off the firewall:
systemctl stop firewalld
Turn off redis service
ps -ef |grep -i redis # Find a process
kill -9 3667 #Shut down the process
Restart related services
EPOL
Errors during downloading metadata for repository 'EPOL':
-Status code: 404 for htpp://repo.openeuler.org/openEuler-21.09/EPOL/repomd.xmlPlease note that:
sudo vi/etc/yum.rest.d/openeuler.repo
Please note that
[EPOL]
name=EPOL
baseurl=http://repo.openeuler.org/openEuler-21.09/EPOL/$basearch/
enabled=1
gpgcheck=1
gpgkey=http://repo.openeuler.org/openEuler-21.09/OS/$basearch/RPM-GPG-KEY-openEulerThe correct address is:
name=EPOL
baseurl= http://repo.openeuler.org/openEuler-21.09/EPOL/main/ $basearch/
Save, exit and execute again.
Client error: could not get a resource from the pool
1. Reason & Solution
Concurrency is indeed too high, and the link pool configuration parameters are unreasonable. Solution: adjust the configuration parameters; The execution queue of the capacity expansion node redis is occupied by a large number of operations or time-consuming operations. Solution: optimize slow operations; Slow operation is prohibited. There is a hot key solution: split the key and distribute the pressure to each redis node; Increase the local memory. First check the local memory, and then go to a node in redis. The link pool is exhausted. Solution: solve the problem of data skew, execute time-consuming commands, resulting in Ping timeout. Solution: disable time-consuming commands, such as: keys *; Optimize the time-consuming operation. There is a bug in the lower version of jedis package. Solution: upgrade the jedis version
2. Hot key scene sorting
Question 01:
Frequent IP access in a region
Solution:
Increase the application local cache and LRU maintain a certain number of hot IP addresses
Question 02:
Frequently query a large Zset set
Solution:
Split by business dimension; Split by data number segment
3. Sort out the scenario when a node’s link pool is exhausted
Homicide caused by hashtag abuse
An error occurred when starting redis: # handleservicecommands: system error thought. Error code = 1056, message = startservice failed: unknown error
in fact, the current redis server has been started, and then an error is reported when you start it again. Just turn off and restart.
redis-server --service-stop
redis-server --service-start
redis-cli.exe -h 127.0.0.1 -p 6379
Error reporting reason
Java compiler setting error in project structure or setting
resolvent
1. Project structure
Click f I l e → P R O j e c t s t r u c t u r e file \ rightarrow project structurefile → projectstructure
Ensure that the SDK versions under project are the same
2、Preferences
error 1
WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128
The length of the largest listening queue of each port does not meet this high-load environment and needs to be adjusted
Solution:echo 2048 > /proc/sys/net/core/somaxconn
error 2
WARNING overcommit_memory is set to 0! Background save may fail under low memory condition
Memory excess warning, setting the current memory to 0 will cause the background save to fail
Solution:
echo "vm.overcommit_memory=1" > /etc/sysctl.conf
#Refresh the configuration file to ensure it takes effect
sysctl vm.overcommit_memory=1
error 3
WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis
Enabling transparent huge page (THP) support in the kernel will cause Redis delays and memory usage issues
Solution:
echo never > /sys/kernel/mm/transparent_hugepage/enabled
error 4
Error condition on socket for SYNC: Connection reset by peer
The connection was refused because the main server may have bound its own IP address
Solution:
#Modify the master node configuration file
vim /etc/redis/6379.conf
bind 0.0.0.0 #Modify the listening address on line 70 to 0.0.0.0
After redis is connected, a (error) noauth authentication required. error is returned after executing the monitor command
[root@m214 src]# ./redis-cli -p 6412
127.0.0.1:6412> monitor
(error) NOAUTH Authentication required.
The reason is that you did not log in with password authentication
Solution:
view the redis configuration file to see the corresponding pass.
# Generated by CONFIG REWRITE
masterauth "2651080c6814a4a9d62da69a12f962b6"
requirepass "2651080c6814a4a9d62da69a12f962b6"
Then, after logging in with redis cli, execute the command auth + password, and then execute the monitor command
[root@m214 src]# ./redis-cli -p 6412
127.0.0.1:6412> auth 2651080c6814a4a9d62da69a12f962b6
OK
127.0.0.1:6412> monitor
OK
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
Execute
Error message
Node 127.0.0.1:30001 is not configured as a cluster node
Error reason:
/Cluster enabled yes is commented out in the root/soft/redis-5.0.5/redis.conf file
Solution:
VI redis.conf uncomment and save.
Restart redis
If it still fails to start, refer to redis cluster tutorial – redis
https://redis.io/topics/cluster-tutorial
Installation starts here
This error is encountered in the redis interface
127.0.0.1:6379> select 0
(error) NOAUTH Authentication required.
This error is caused by lack of authorization. You can enter a password to solve it at this time.
127.0.0.1:6379> auth "your Password"
Or specify a password when accessing the ‘redis’ client
redis-cli -h 127.0.0.1 -p 6379 -a "your Password"
Error in starting redis service under Windows creating server TCP listening socket 127.0.0.1:6379: bind: no error
Solution:
