Redis, as an open-source tool, is free to use in its basic form. You can download and use it without any cost. This makes it an attractive solution for businesses of all sizes who want a robust in-memory data store or cache.
Here's how you might install Redis on a Unix-like system, such as Ubuntu. It's straightforward and free:
However, when you start considering managed Redis services or enterprise offerings, costs will become a factor. These services handle administrative tasks such as setup, scaling, and backups, but they come with a price tag.
For example, AWS offers ElastiCache for Redis, while Microsoft Azure offers Azure Cache for Redis, which both offer managed Redis services. But, these services are not free and their pricing depends on factors like the instance type, region, and additional features.
Also, remember that while the software itself might be free, running it isn't necessarily without costs. Hardware, electricity, maintenance time, etc., will all need to be factored into the total cost of ownership of running Redis, especially at scale.
In conclusion, whether Redis is "expensive" or not largely depends on your specific use case, infrastructure, scale, and whether you're willing or able to manage it yourself. If you're using a cloud provider's managed service, you should consult their specific pricing details.