Redis is an open-source, in-memory data structure store that can serve as a database, cache, and message broker. It stores data structures such as hashes, lists, strings, sets, sorted sets with range queries, hyper logs, bitmaps, and geospatial indexes with radius queries.
Due to its simplistic nature, storing data in memory and its key-value architecture, Redis is blazingly fast, making it an efficient choice as a caching mechanism for other database.
Redis also offers a very powerful CLI with built-in tools and features. One tool is the Redis
To follow along with this tutorial, you will need to ensure you have a Redis server installed and running on your system
You can check the resources below to learn more.
Redis Check if Server is Up using
Redis ping is a simple command that you can use to test whether your Redis server is up and running. To use Redis ping, type the following into your terminal:
If your server is up, you will see the following output:
Otherwise, Reis will return an error message indicating it cannot connect to the server.
An example error message is as shown:
Could not connect to Redis at 127.0.0.1:6379: Connection refused
Troubleshooting your Redis Server
There are a few reasons why your Redis server might be down. It could be that the Redis service is not running or that there is a firewall blocking the Redis port.
To check if the Redis service is running, you can use the following command:
ps -ef | grep redis-server
If you see such an output, then it means that the Redis service is running:
root 29673 1 0 Jan03 ? 00:00:01 /usr/local/bin/redis-server 127.0.0. redis 29680 29673 0 Jan03 pts/0 00:00:00 grep --color=auto redis-server
You will need to start the Redis service if you don't see any output or if the output shows the Redis service is not running.
To start the Redis service, you can use the following command:
sudo systemctl start redis-server.service
Once the Redis service is started, you can check if the server is up and running by pinging it again or using
sudo systemctl status redis.service
If you still don't see the "PONG" response, then it is most likely that there is a firewall blocking the Redis port.
To allow Redis traffic through the firewall, you can use the following command:
sudo ufw allow redis-server
Once you allow Redis traffic through the firewall, you should be able to ping the Redis server and see the "PONG" response.
So there you have it! Now you know how to use Redis-cli to ping your Redis server to check if it's alive and several ways to troubleshoot your server if it is down. Stay tuned for more tips and tricks on working with Redis.
If you need assistance, drop your questions in the comments.
Thanks for reading!