I am storing users' code in file system, at present EBS in AWS. I am looking improving the availability and want to reduce the chances of outage due to EBS going down. EFS appears to be a reasonable option.
I understand EFS will be slower than EBS and EFS is more expensive than EBS. I want to know, if there is any performance benchmark done to measure the read and write latencies of EFS and comparison with EBS?
This AWS forums thread shows you some of the problems that some customers have had with eFS latency and AWS reaction. Some customers assert they have had 1+ second latency, to which AWS support say that's not normal, they'll investigate.
My current experience in EU-West appears to suggest that for a series of 150,000 small read operations of about 2.5KB each, my EC2<->EFS is maxing out at 200 read ops per second, so we might guess at no more than 1/200th of a second or 5ms for typical effective latency.
I say "effective latency" because that's really reporting a bandwidth, not a latency. I haven't written timing code to measure round-trip latency.
You can improve it by paying for a bigger drive (which includes bigger IOPS in the price) or for reserved IOPS.