Meta is Saving Millions of Dollars for This Clever Memory Hack
Engineers at Facebook’s parent company Meta have revealed how they’ve been able to offer free memory using a software solution called Transparent Memory Offloading (TMO).
it’s part of now Linux The kernel and, in essence, automatically offloads data to other storage tiers (such as Samsung’s CX memory expander) that are less expensive and more power efficient than memory.
Savings are important; TMO is running on millions of Facebook Server For over a year, a memory saving of about a third per server. While this is likely to be negligible across dozens or even hundreds of servers, FacebookThe sheer scale of the field presents a unique challenge.
Analysis: Facebook’s overwhelming appetite for RAM
The world’s largest social network has approximately three billion monthly active users and millions of servers spread across approximately 21 locations around the world. Should each server have an average of 128GB of RAM, that would be 256 million GB (or 256PB) to hit Which, at an average cost of $4 per GB (DDR4 ECC RAM), is roughly $1 billion worth of memory. This is on the assumption that Facebook has at least two million servers (Facebook’s blog quoted “millions of servers” in early July 2018), the actual number is likely to be far higher.
Numbers submitted by the team working on TMO showed that memory costs accounted for a third of Meta’s server bill, with compressed RAM and SSD accounting for less than 11%. More worryingly, since Facebook launched its first generation of servers, the cost burden of RAM (as a percentage of total infrastructure) has more than doubled (it currently ranks fourth). .
Adopting TMO also comes with some drawbacks; Most notably, performance degradation. But the benefits, in terms of power and memory savings, combined with hardware improvements far outweigh the disadvantages and future iterations (eg faster ssd or CXL drives) will offer even less.