In our practice, the production environment's ops is often quickly goes up and down and there will be tremendous key evictions when ops rises rapidly due to many user buffers. We're seeking a way to solve this.
Maybe we should distinct keyspace used memory from other uses.
related issue: #4438 #4496 #4213

By the way we're using version 3.0.7 and 4.0.11. I had a glance at version 5, but there seems no changes about this.