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目录

一、Linux

1、Linux异常解决

1、JDK安装

1、Linux卸载JDK

2、Linux安装JDK

2、Redis安装

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一、Linux

1、Linux异常解决

1、Another app is currently holding the yum lock; waiting for it to exit...

解决办法:
rm -f /var/run/yum.pid1、杀死这个应用程序
ps aux | grep yum(查询有关yum的进程，找到那个更新进程)
命令：kill -s 9 2833 pid
kill 的用法： kill [信号代码] 进程ID
注：信号代码可以省略；我们常用的信号代码是 -s 9 ，表示强制终止；
2833是这个进程的ID
2、强制关掉yum进程，并重新运行yum
#rm -f /var/run/yum.pid
注：强制删除：#rm -f
解释：强制删除文件：  /var/run/yum.pid
如果上面方法不行的话，尝试使用下面的方法。

1、JDK安装

1、Linux卸载JDK

1、查看java -version查看linux系统是否已经安装jdk

[root@localhost java]# java -version
java version "1.8.0_202"
Java(TM) SE Runtime Environment (build 1.8.0_202-b08)
Java HotSpot(TM) 64-Bit Server VM (build 25.202-b08, mixed mode)

2、查看jdk安装的路径：which java

[root@localhost java]# which java
/usr/java/jdk1.8.0_202/bin/java

3、卸载jdk

rm -rf /usr/java/jdk1.8.0_202/bin/java

4、删除环境变量：export开头的三行

[root@localhost java]# vi /etc/profile
export JAVA_HOME=/usr/java/jdk1.8.0_202
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

5、检查下系统自带的jdk，并删除它

rpm -qa |grep java
rpm -qa |grep jdk
rpm -qa |grep gcj

2、Linux安装JDK

JDK官方下载地址

1、将文件jdk-21.0.1_linux-x64_bin.tar.gz移动到/usr/java下，usr下没有java文件夹，可以先创建java文件夹：mkdir java

[root@localhost java]# ls
jdk-21.0.1_linux-x64_bin.tar.gz

2、解压

[root@localhost java]# tar -zxvf jdk-21.0.1_linux-x64_bin.tar.gz

3、在/etc/profile文件中，配置环境变量，使JDK在所有用户中生效

编辑文件，在最后添加如下三行：

export JAVA_HOME=/usr/java/jdk-21.0.1
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

4、保存退出后，执行source /etc/profile使修改的环境变量生效

[root@localhost java]# source /etc/profile

5、使用java -version命令测试是否成功

[root@localhost etc]# java -version
java version "21.0.1" 2023-10-17 LTS
Java(TM) SE Runtime Environment (build 21.0.1+12-LTS-29)
Java HotSpot(TM) 64-Bit Server VM (build 21.0.1+12-LTS-29, mixed mode, sharing)

2、Redis安装

Redis是基于c语言编写的需要安装依赖，需要安装gcc：

yum install gcc-c++

查看gcc版本：

 gcc -v

下载Redis

wget http://download.redis.io/releases/redis-7.2.3.tar.gz[root@localhost redis]# wget http://download.redis.io/releases/redis-7.2.3.tar.gz                                                 --2023-11-24 00:18:22--  http://download.redis.io/releases/redis-7.2.3.tar.gz
Resolving download.redis.io (download.redis.io)... 45.60.125.1
Connecting to download.redis.io (download.redis.io)|45.60.125.1|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 3384816 (3.2M) [application/octet-stream]
Saving to: ‘redis-7.2.3.tar.gz’100%[========================================================================================>] 3,384,816    200KB/s   in 23s2023-11-24 00:18:56 (146 KB/s) - ‘redis-7.2.3.tar.gz’ saved [3384816/3384816]

解压并安装Redis

tar -zvxf redis-7.2.3.tar.gz

cd redis-7.2.3/

make[root@localhost redis-7.2.3]# make install
cd src && make install
which: no python3 in (/usr/java/jdk-21.0.1/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin)
make[1]: Entering directory `/usr/lwz_tools/redis/redis-7.2.3/src'CC Makefile.dep
make[1]: Leaving directory `/usr/lwz_tools/redis/redis-7.2.3/src'
which: no python3 in (/usr/java/jdk-21.0.1/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin)
make[1]: Entering directory `/usr/lwz_tools/redis/redis-7.2.3/src'Hint: It's a good idea to run 'make test' ;)INSTALL redis-serverINSTALL redis-benchmarkINSTALL redis-cli
make[1]: Leaving directory `/usr/lwz_tools/redis/redis-7.2.3/src'
[root@localhost redis-7.2.3]#

redis默认安装路径：/usr/local/bin

[root@localhost redis-7.2.3]# cd /usr/local/bin
[root@localhost bin]# ls
redis-benchmark  redis-check-aof  redis-check-rdb  redis-cli  redis-sentinel  redis-server

redis默认不是后台启动，更改启动方式

有关redis配置文件的一些说明：

然后修改redis.conf文件中的一些配置

# 允许访问的地址，默认是127.0.0.1，会导致只能在本地访问。修改为0.0.0.0则可以在任意IP访问，生产环境不要设置为0.0.0.0
bind 0.0.0.0
# 守护进程，修改为yes后即可后台运行
daemonize yes 
# 密码，设置后访问Redis必须输入密码
requirepass 123456# 监听的端口
port 6379
# 工作目录，默认是当前目录，也就是运行redis-server时的命令，日志、持久化等文件会保存在这个目录
dir .
# 数据库数量，设置为1，代表只使用1个库，默认有16个库，编号0~15
databases 1
# 设置redis能够使用的最大内存
maxmemory 512mb
# 日志文件，默认为空，不记录日志，可以指定日志文件名
logfile "redis.log"

启动redis-server服务

通过指定配置文件启动服务

redis-server redisconfig/redis.conf

使用redis-cli连接测试

redis-cli -p 6379[root@localhost bin]# redis-cli -p 6379
127.0.0.1:6379> ping
PONG
127.0.0.1:6379>#有密码需要 auth 你的密码

查看redis的进程是否开启（新开一个会话）

[root@localhost ~]# ps -ef|grep redis
root      7328     1  0 02:06 ?        00:00:00 redis-server 0.0.0.0:6379
root      7333  1565  0 02:06 pts/0    00:00:00 redis-cli -p 6379
root      7384  7345  0 02:12 pts/1    00:00:00 grep --color=auto redis
[root@localhost ~]#

如何关闭redis服务

127.0.0.1:6379> shutdown
not connected> exit
[root@localhost bin]#

再次查看服务：

[root@localhost ~]# ps -ef|grep redis
root      7386  7345  0 02:14 pts/1    00:00:00 grep --color=auto redis

设置Redis开机自启动

首先，新建一个系统服务文件：

vi /etc/systemd/system/redis.service

内容  /usr/local/bin/redis.conf指定配置文件路径可修改

[Unit]
Description=redis-server
After=network.target[Service]
Type=forking
ExecStart=/usr/local/bin/redis-server /usr/local/bin/redis.conf
PrivateTmp=true[Install]
WantedBy=multi-user.target

然后重载系统服务：

systemctl daemon-reload

现在，我们可以用下面这组命令来操作redis了：

# 启动
systemctl start redis
# 停止
systemctl stop redis
# 重启
systemctl restart redis
# 查看状态
systemctl status redis

执行下面的命令，可以让redis开机自启：

systemctl enable redis

性能测试

redis 性能测试的基本命令如下：

redis-benchmark [option] [option value]

测试100个并发链接，每个并发100000请求

redis-benchmark -h localhost -p 6379 -c 100 -n 100000

Summary:throughput summary: 10989.01 requests per secondlatency summary (msec):avg       min       p50       p95       p99       max5.135     1.600     4.479     9.823    13.223    25.231
====== LRANGE_600 (first 600 elements) ======100000 requests completed in 10.48 seconds     #100000个请求  所有请求在10.48秒完成100 parallel clients                           #100个客户端3 bytes payload                                #每次3个字节keep alive: 1                                  #活跃1个host configuration "save": 3600 1 300 100 60 10000host configuration "appendonly": nomulti-thread: noLatency by percentile distribution:
0.000% <= 1.463 milliseconds (cumulative count 1)
50.000% <= 5.175 milliseconds (cumulative count 50271)
75.000% <= 5.999 milliseconds (cumulative count 75004)
87.500% <= 8.087 milliseconds (cumulative count 87514)
93.750% <= 10.631 milliseconds (cumulative count 93761)
96.875% <= 13.255 milliseconds (cumulative count 96875)
98.438% <= 15.199 milliseconds (cumulative count 98438)
99.219% <= 17.823 milliseconds (cumulative count 99221)
99.609% <= 20.319 milliseconds (cumulative count 99611)
99.805% <= 23.279 milliseconds (cumulative count 99807)
99.902% <= 25.503 milliseconds (cumulative count 99903)
99.951% <= 26.863 milliseconds (cumulative count 99952)
99.976% <= 27.727 milliseconds (cumulative count 99976)
99.988% <= 28.351 milliseconds (cumulative count 99988)
99.994% <= 28.847 milliseconds (cumulative count 99994)
99.997% <= 29.087 milliseconds (cumulative count 99997)
99.998% <= 29.279 milliseconds (cumulative count 99999)
99.999% <= 29.391 milliseconds (cumulative count 100000)
100.000% <= 29.391 milliseconds (cumulative count 100000)

Linux常用命令

干我们这行，啥时候懈怠，就意味着长进的停止，长进的停止就意味着被淘汰，只能往前冲，直到凤凰涅槃的一天！