Redis slow query log:
vim /etc/redis.conf
slowlog-log-slower-than 10000
Redis also has a slow query log similar to MySQL. This parameter defines that a query execution time exceeding 10000 microseconds will be recorded in the log. Among them, 1 second = 1,000,000 microseconds.
slowlog-max-len 128
This parameter defines the maximum number of slow query logs. In fact, Redis's slow log is also stored in memory, which is also a k/v form of data.
supplement:
slowlog get //List all slow query logs
slowlog get 2 //Only list 2
slowlog len //View the number of slow query logs
Use Redis in PHP (installed in the previous document without installing php)
php install redis extension module-install using pecl
/usr/local/php-fpm/bin/pecl install redis
报错：Cannot find autoconf. Please check your autoconf installation and the$PHP_AUTOCONF environment variable. Then, rerun this script.
ERROR: `phpize' failed
Solution: yum -y install m4 autoconf
Re-install using pecl:
/usr/local/php-fpm/bin/pecl install redis
vim /usr/local/php/etc/php.ini //Add extension = redis.so in the last line
Check if there is a redis module
/usr/local/php-fpm/bin/php -m
Install from source code
wget http://pecl.php.net/get/redis-5.3.2.tgz
tar -xzvf redis-5.3.2.tgz
cd redis-5.3.2
/usr/local/php-fpm/bin/phpize
./configure --with-php-config=/usr/local/php-fpm/bin/php-config
make && make install
vi /usr/local/php/etc/php.ini //Add extension = redis.so
Use **redis -storage ** session** in php **
vim /usr/local/php-fpm/etc/php.ini
;session.save_handler = files
Add two lines below
session.save_handler = "redis"
session.save_path = "tcp://127.0.0.1:6379"
Or it can be configured like this in the apache virtual host configuration file:
php_value session.save_handler "redis"
php_value session.save_path "tcp://127.0.0.1:6379"
Or add to the pool corresponding to the php-fpm configuration file:
php_value[session.save_handler] = redis
php_value[session.save_path] = "tcp://127.0.0.1:6379"
Create test file
wget http://study.lishiming.net/.mem_se.txt
mv .mem_se.txt session.php
Test: /usr/local/php-fpm/bin/php session.php
Redis master-slave configuration
Through the persistence function, Redis guarantees that data will not be lost (or a small amount of loss) even when the server is restarted. However, since the data is stored on a server, if the server fails, such as the hard disk is broken, It can also cause data loss.
In order to avoid a single point of failure, we need to deploy multiple copies of data on multiple different servers. Even if one server fails, other servers can continue to provide services.
This requires that when the data on one server is updated, the updated data is automatically synchronized to other servers. At this time, Redis master-slave replication is used.
Two linux:
Main redis: 192.168.111.136
From redis: 192.168.111.140
Main redis set password:
vim /etc/redis.conf
requirepass admin123
appendonly yes
bind 127.0.0.1 192.168.111.136
Modify the configuration from redis
vim /etc/redis.conf
# replicaof <masterip> <masterport>
replicaof 192.168.111.136 6379
# masterauth <master-password>
masterauth admin123
bind 127.0.0.1 192.168.111.140
Restart the master-slave redis service
systemctl restart redis
Test: The master redis creates a key to see if the slave redis is displayed synchronously
Main redis:
[root@jinkai redis-6.0.6]# redis-cli
127.0.0.1:6379> auth admin123
OK
127.0.0.1:6379> info replication
# Replication
role:master
connected_slaves:1
slave0:ip=192.168.111.140,port=6379,state=online,offset=294,lag=0
master_replid:a678d12ebaea9481bc9d322ef9b9fcc8330a2c3d
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:294
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:294
127.0.0.1:6379> flushall
OK
127.0.0.1:6379> set km1 vm1
OK
127.0.0.1:6379> get km1
"vm1"
From redis:
[root@jinkai redis-6.0.6]# redis-cli -a admin123
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
Warning: AUTH failed
127.0.0.1:6379> info replication
# Replication
role:slave
master_host:192.168.111.136
master_port:6379
master_link_status:up
master_last_io_seconds_ago:3
master_sync_in_progress:0
slave_repl_offset:350
slave_priority:100
slave_read_only:1
connected_slaves:0
master_replid:a678d12ebaea9481bc9d322ef9b9fcc8330a2c3d
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:350
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:99
repl_backlog_histlen:252
127.0.0.1:6379> get km1
"vm1"
The default replica-read-only yes for writing data to slave redis, if it is no, you can write data to slave
127.0.0.1:6379> set ks1 vs1
(error) READONLY You can't write against a read only replica.