How to save memory from unpopular/cold Redis?

Question

We have a lot of Redis instances, consuming TBs of memory and hundreds of machines.

With our business activities goes up and down, some Redis instances are just not used that frequent any more -- they are "unpopular" or "cold". But Redis stores everything in memory, so a lot of infrequent data that should have been stored in cheap disk are occupying expensive memory.

We are exploring a way to save the memory from these unpopular/cold Redis, as to reduce our machines usage.

We cannot delete data, nor can we migrate to other database. Are there some way to achieve our goals?

PS: We are thinking of some Redis compatible product that can "mix" memory and disk, i.e. it stores hot data in memory but cold in disk, and USING LIMITED RESOURCES. We know RedisLabs' "Redis on Flash(ROF)" solution, but it uses RocksDB, which is very memory unfriendly. What we want is a very memory restrained product. Besides, ROF is not open source :(

Thanks in advance!

Answer 1

ElastiCache Redis now supports data tiering. Data tiering provides a new cost optimal option for storing data in Redis by utilizing lower-cost local NVMe SSDs in each cluster node in addition to storing data in memory. It is ideal for workloads that access up to 20 percent of their overall dataset regularly, and for applications that can tolerate additional latency when accessing data on SSD. More details about data tiering can be found here.