Question: How to restart Redis?

Answer

To restart Redis, you can use one of the following methods depending on your Redis setup:

1. Use Redis CLI

You can use the Redis command-line interface (CLI) to restart Redis.

First, connect to your Redis instance using the redis-cli command:

```
redis-cli
```

Then, issue the SHUTDOWN command:

```
SHUTDOWN
```

This will gracefully shut down Redis, saving any unsaved changes to disk and then restart it.

2. Use Redis init script

If Redis was installed using a package manager on Linux, such as apt or yum, it likely came with an init script that you can use to start, stop, or restart Redis.

On Ubuntu, for example, you can use the following command to restart Redis:

```
sudo service redis-server restart
```

On CentOS/RHEL, you can use:

```
sudo systemctl restart redis
```

3. Use Redis configuration file

You can also use the Redis configuration file to restart Redis. This method is useful if you want to change Redis settings before restarting it.

First, open the Redis configuration file in an editor:

```
sudo nano /etc/redis/redis.conf
```

Then, find the pidfile parameter and note down its value. This parameter specifies the path to the Redis process ID file.

```
pidfile /var/run/redis/redis-server.pid
```

Now, kill the Redis process using the kill command:

```
sudo kill $(cat /var/run/redis/redis-server.pid)
```

Finally, start Redis again:

```
sudo systemctl start redis
```

Make sure to replace the paths and commands above with the appropriate ones for your Redis setup.