21.18 redis慢查询日志

21.18 redis慢查询日志

编辑配置文件/etc/redis.conf
针对慢查询日志，能够设置两个参数，一个是执行时长，单位是微秒，另外一个是慢查询日志的长度。当一个新的命令被写入日志时，最老的一条会从命令日志队列中被移除。
slowlog-log-slower-than 1000 //单位ms，表示慢于1000ms则记录日志
slowlog-max-len 128 //定义日志长度，表示最多存128条
slowlog get //列出全部的慢查询日志
slowlog get 2 //只列出2条
slowlog len //查看慢查询日志条数

##redis慢查询日志默认是开启的：
[root@Dasoncheng ~]# vim /etc/redis.conf
# The following time is expressed in microseconds, so 1000000 is equivalent
# to one second. Note that a negative number disables the slow log, while
# a value of zero forces the logging of every command.
slowlog-log-slower-than 10000

# There is no limit to this length. Just be aware that it will consume memory.
# You can reclaim memory used by the slow log with SLOWLOG RESET.
slowlog-max-len 128

这里咱们将执行时常修改成10微秒，看看效果：

# The following time is expressed in microseconds, so 1000000 is equivalent
# to one second. Note that a negative number disables the slow log, while
# a value of zero forces the logging of every command.
slowlog-log-slower-than 10  ##正常实验环境下，查询都会超过10微秒

# There is no limit to this length. Just be aware that it will consume memory.
# You can reclaim memory used by the slow log with SLOWLOG RESET.
slowlog-max-len 128
#保存退出
[root@Dasoncheng ~]# killall redis-server
[root@Dasoncheng ~]# redis-server /etc/redis.conf 
[root@Dasoncheng ~]# redis-cli 
127.0.0.1:6379> slowlog get   ##这里显示0为1条慢查询日志
1) 1) (integer) 0
   2) (integer) 1507942013
   3) (integer) 899
   4) 1) "COMMAND"
   5) "127.0.0.1:40790"
   6) ""
127.0.0.1:6379> keys *
 1) "k3"
 2) "key2"
 3) "setc"
 4) "hash1"
 5) "s1"
 6) "lista"
 7) "set1"
 8) "l1"
 9) "setd"
10) "set2"
11) "list"
12) "key10"
13) "setb"
14) "key1"
15) "k2"
16) "sete"
17) "k1"
18) "seta"
19) "set3"
127.0.0.1:6379> get k3
"3"
127.0.0.1:6379> get key2
"200"
127.0.0.1:6379> slowlog get
1) 1) (integer) 3
   2) (integer) 1507942047
   3) (integer) 58
   4) 1) "get"
      2) "key2"
   5) "127.0.0.1:40790"
   6) ""
2) 1) (integer) 2
   2) (integer) 1507942031
   3) (integer) 29
   4) 1) "keys"
      2) "*"
   5) "127.0.0.1:40790"
   6) ""
3) 1) (integer) 1
   2) (integer) 1507942021
   3) (integer) 22
   4) 1) "slowlog"
      2) "get"
   5) "127.0.0.1:40790"
   6) ""
4) 1) (integer) 0
   2) (integer) 1507942013
   3) (integer) 899
   4) 1) "COMMAND"
   5) "127.0.0.1:40790"
   6) ""
127.0.0.1:6379> slowlog get 2  ##只获取最近两条慢查询日志；
1) 1) (integer) 4
   2) (integer) 1507942052
   3) (integer) 41
   4) 1) "slowlog"
      2) "get"
   5) "127.0.0.1:40790"
   6) ""
2) 1) (integer) 3
   2) (integer) 1507942047
   3) (integer) 58
   4) 1) "get"
      2) "key2"
   5) "127.0.0.1:40790"
   6) ""
127.0.0.1:6379> slowlog len  ##显示全部慢查询日志条数；
(integer) 6

21.19 php安装redis扩展模块

cd /usr/local/src
 wget https://coding.net/u/aminglinux/p/yuanke_centos7/git/raw/master/21NOSQL/phpredis.zip
 unzip phpredis.zip
 cd phpredis-develop
 /usr/local/php-fpm/bin/phpize
 ./configure --with-php-config=/usr/local/php-fpm/bin/php-config
 make 
 make install
 vim /usr/local/php.ini//增长extension=redis.so
 /usr/local/php-fpm/bin/php -m|grep redis//看是否有redis模块
 重启php-fpm服务

21.20 redis存储session

• vim /usr/local/php-fpm/etc/php.ini//更改或增长
  session.save_handler = "redis"
  session.save_path = "tcp://127.0.0.1:6379"
• 或者apache虚拟主机配置文件中也能够这样配置：
  php_value session.save_handler " redis"
  php_value session.save_path " tcp://127.0.0.1:6379" 
• 或者php-fpm配置文件对应的pool中增长：
  php_value[session.save_handler] = redis
  php_value[session.save_path] = " tcp://127.0.0.1:6379 "

wgt http://study.lishiming.net/.mem_se.txt
mv .mem_se.txt /usr/local/apache2/htdocs/session.php
其中session.php内容能够参考https://coding.net/u/aminglinux/p/yuanke_centos7/git/blob/master/21NOSQL/session.php
curl localhost/session.php //结果相似于1443702394<br><br>1443702394<br><br>i44nunao0g3o7vf2su0hnc5440
命令行链接redis，也能够查看到该key以及对应的值
若是想用php链接redis cluster，须要使用predis扩展
安装方法相似phpredis，predis扩展地址https://github.com/nrk/predis

21.21 redis主从配置

为了节省资源，咱们能够在一台机器上启动两个redis服务
cp /etc/redis.conf /etc/redis2.conf
vim /etc/redis2.conf //须要修改port,dir,pidfile,logfile
还要增长一行
slaveof 127.0.0.1 6379
若是主上设置了密码，还须要增长
masterauth aminglinux>com //设置主的密码
启动以前不要忘记建立新的dir目录
redis-server /etc/redis2.conf
测试：在主上建立新的key，在从上查看
注意：redis主从和mysql主从不同，redis主从不用事先同步数据，它会自动同步过去

[root@Dasoncheng ~]# vim /etc/redis2.conf 
[root@Dasoncheng ~]# mkdir /data/redis2
[root@Dasoncheng ~]# redis-server /etc/redis2.conf
[root@Dasoncheng ~]# ps aux |grep redis
root       6411  0.2  0.2 142920  2284 ?        Ssl  08:46   0:02 redis-server 127.0.0.1:6379
root       6498  0.1  0.2 142788  2136 ?        Ssl  09:06   0:00 redis-server 127.0.0.1:6333
root       6505  0.0  0.0 112660   964 pts/2    S+   09:06   0:00 grep --color=auto redis
[root@Dasoncheng ~]# redis-cli -h 127.0.0.1 -p 6333
127.0.0.1:6333> keys *
 1) "set1"
 2) "seta"
 3) "key2"
 4) "l1"
 5) "key10"
 6) "lista"
 7) "s1"
 8) "k1"
 9) "k2"
10) "set3"
11) "key1"
12) "k3"
13) "setd"
14) "set2"
15) "sete"
16) "list"
17) "setc"
18) "setb"
19) "hash1"