How to view server version of Redis

Question: How to view the Redis server version? Use the command line tool redis-cli --version to view the version of the connected server. Use the INFO server command to view the server's internal version and need to parse and return information. In a cluster environment, check the version consistency of each node and can be automatically checked using scripts. Use scripts to automate viewing versions, such as connecting and printing version information with Python scripts.

How to view the server version of Redis? This question seems simple, but it actually has a secret. On the surface, one command can be handled, but it involves Redis's architecture, command execution mechanism, and even network communication details. Do you think it's just a version number? No, there is a lot of knowledge in this!

Let’s talk about the most direct method first, redis-cli command line tool, which is a guy that veteran drivers are familiar with. You just need to open the terminal, connect to your Redis server, and then type in:

 <code class="bash">redis-cli --version</code>

It's that simple? That's right, it's that simple! But this is just the tip of the iceberg. redis-cli itself is a client program that communicates with the Redis server through a network protocol. The commands you enter will be packaged into network data packets, sent to the server, the server parses the commands, performs operations, and then packages the results and sends them back to the client. This seemingly simple process actually contains a lot of details, such as network delay, protocol resolution, command processing, etc. A slow network, or an overloaded server, can cause this simple command to execute slowly or even fail.

If you want to view the version internally on the Redis server, you have to use some "internal power". Redis itself provides an INFO command, which can return various information about the server, including version number:

 <code class="redis">INFO server</code>

After executing this command, you will get a lot of information, which contains the redis_version field, which is your Redis version number. Note that the INFO command returns a lot of information, and you need to parse and find the version number yourself. You can use scripts or programming languages ​​to process this information and extract the parts you want. This is a bit more complicated than using redis-cli --version directly, but it gives you a deeper understanding of the operating status of the Redis server.

Both methods have their own advantages and disadvantages. redis-cli --version is simple and crude, suitable for fast viewing of versions, but it can only view the server version of the client connected to, and it depends on the client program. INFO server provides more comprehensive information, but requires additional processing to extract the version number, and it requires you to already connect to the Redis server.

Going deeper, if you are in a cluster environment, you need to consider whether the version of each node is consistent. Version inconsistency can lead to various problems such as data incompatibility, command not supported, etc. So, in a cluster environment, you need to execute INFO server commands on each node, or write a script to automatically check the versions of all nodes.

Finally, I will share another tip. If you need to check the Redis version frequently, consider writing a simple script to automate the process. For example, use Python:

 <code class="python">import redis r = redis.Redis(host='localhost', port=6379) info = r.info('server') print(f"Redis version: {info['redis_version']}")</code>

This code is concise and clear, easy to understand and maintain. It can automatically connect to the Redis server, obtain version information, and print it out. You only need to modify host and port parameters to adapt to different environments. Remember that the readability and maintainability of the code are equally important, don't write it into an incomprehensible "pasta code". Good code, like elegant dance, pleasing to the eye and easy to understand. On the contrary, it is like a pot of stewing, which makes people feel troublesome. This is the real way to programming!

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