[大数据]redis的python使用

windows下

今天做一个练习需要用到python的redis模块，但安装了redis模块后，运行脚本却得到这样的结果：

PS H:\project\python course\python_pra> python producer.py
生产者生产了两个数字：3, 95
Exception in thread Thread-1:
Traceback (most recent call last):
  File "D:\Python39\lib\site-packages\redis\connection.py", line 567, in connect
    sock = self._connect()
  File "D:\Python39\lib\site-packages\redis\connection.py", line 625, in _connect
    raise err
  File "D:\Python39\lib\site-packages\redis\connection.py", line 613, in _connect
    sock.connect(socket_address)
ConnectionRefusedError: [WinError 10061] 由于目标计算机积极拒绝，无法连接。

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "D:\Python39\lib\threading.py", line 954, in _bootstrap_inner
    self.run()
  File "H:\project\python course\python_pra\producer.py", line 17, in run
    self.queue.rpush('producer', json.dumps((a, b)))
  File "D:\Python39\lib\site-packages\redis\commands\core.py", line 1809, in rpush
    return self.execute_command('RPUSH', name, *values)
  File "D:\Python39\lib\site-packages\redis\client.py", line 1068, in execute_command
    conn = self.connection or pool.get_connection(command_name, **options)
  File "D:\Python39\lib\site-packages\redis\connection.py", line 1173, in get_connection
    connection.connect()
  File "D:\Python39\lib\site-packages\redis\connection.py", line 571, in connect
    raise ConnectionError(self._error_message(e))
redis.exceptions.ConnectionError: Error 10061 connecting to localhost:6379. 由于目标计算机积极拒绝，无法连接。.

很长啊，啪的一下，就那么长了，这里主要是说，本机的redis服务没有启动，而我的电脑还么安装redis，所以现在先安装redis。
安装网址
点进去下载压缩包即可

然后解压缩在你需要安装的目录，然后我们来看看能不能启动redis服务

./redis-server redis.windows.conf

对应目录输入该命令，出现以下界面就表明redis服务已启动

接下来我们先看看我们的代码是否可用了

嗯，很流畅。那么接下来呢？结束啦？不是哦，你的redis服务现在是属于软件点击启动才启动，但我们每次使用redis模块都要到该目录下输入命令启动一次？太麻烦了，我们设置一下让它在电脑中跟随其他服务启动而启动。
同样是该目录下输入以下命令

PS D:\Redis-x64-3.2.100> ./redis-server --service-install redis.windows.conf --loglevel verbose
[11896] 04 Dec 17:39:05.607 # HandleServiceCommands: system error caught. error code=1073, message = CreateService failed: unknown error

PS D:\Redis-x64-3.2.100>

嗯。。。。。。失败了，为什么呢？
查了一下，它说之前已经安装了，所以启动同样的命令失败，嗯？所以我关闭了也算是服务在后台？我不确定，现在也不检验这个东西，那我们就先卸载一下然后在启动吧

PS D:\Redis-x64-3.2.100> ./redis-server --service-uninstall
[10332] 04 Dec 17:41:15.503 # Redis service successfully uninstalled.
PS D:\Redis-x64-3.2.100> ./redis-server --service-install redis.windows.conf --loglevel verbose
[1884] 04 Dec 17:42:04.596 # Granting read/write access to 'NT AUTHORITY\NetworkService' on: "D:\Redis-x64-3.2.100" "D:\Redis-x64-3.2.100\"
[1884] 04 Dec 17:42:04.596 # Redis successfully installed as a service.
PS D:\Redis-x64-3.2.100> ./redis-server --service-start
[13984] 04 Dec 17:42:41.424 # Redis service successfully started.
PS D:\Redis-x64-3.2.100>

然后我关闭了cmd终端，试验一下可行性

嗯，可以。哈哈哈。

linux的centos7云服务器

在windows系统中已经尝试过了，那linux环境呢？下面是我的腾讯服务器的实验，腾讯服务器装载的是centos7系统，它已经内置了python，所以我先安装了pip管理。

yum install python-pip

然后安装redis模块

pip install redis

但却出现以下错误：

 Downloading http://mirrors.tencentyun.com/pypi/packages/da/f6/c83229dcc3635cdeb51874184241a9508ada15d8baa337a41093fab58011/pip-21.3.1.tar.gz (1.7MB)
    100% |████████████████████████████████| 1.7MB 3.3MB/s 
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-VjaPWF/pip/setup.py", line 7
        def read(rel_path: str) -> str:
                         ^
    SyntaxError: invalid syntax
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-VjaPWF/pip/

查了一下，资料显示是我的python版本太老了，不支持该模块，所以要安装一下python3，然后安装redis，这里要用pip3

yum install python3
pip3 install redis

然后我们的模块都备全了，要开启一下服务。

redis-server

然后运行一下程序即可，注意之前是安装了python3，所以运行也得是它

[root@VM-0-17-centos ~]# python3 producer.py
生产者生产了两个数字：{a},{b}
生产者生产了两个数字：{a},{b}
生产者生产了两个数字：{a},{b}
生产者生产了两个数字：{a},{b}
生产者生产了两个数字：{a},{b}
生产者生产了两个数字：{a},{b}
^Z
[2]+  Stopped                 python3 producer.py

结果如上所示，可用，这里只是进行一下简单的使用，所以linux中的服务启动等就不继续了。
不过redis的启动在win11的ubuntu子系统上出错

457:M 04 Dec 2021 21:34:20.401 # Server initialized
457:M 04 Dec 2021 21:34:20.401 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
457:M 04 Dec 2021 21:34:20.402 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
457:M 04 Dec 2021 21:34:20.404 * Ready to accept connections

这里先做个记录吧，不进行了。