3 ms·

But it doesn't store the data on disk. It should be compared to Memcached, not to a real storage engine.

• dchichkov 12y ago
  Unlike Memcached or Redis, RAMCloud provides durability: * Automatic replication, crash recovery, and fail-over (no loss of availability if a server fails) * Durability guarantee: data is always replicated and durable before operations return, without significant performance hit (subject to the requirement for persistent buffers on backups).
  • imaginenore 12y ago
    So? Power goes out in your data center, all the data is lost. Nothing stops you from replicating memcached.
  • grogers 12y ago
    You can't make a durable write to disk in 15us. SSDs are around 2 orders of magnitude slower than that. 15us is about right for in memory on two nodes in a single data center though. Most people wouldn't consider that durable though.