EBS vs EFS read and write latencies

Question

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?

Endowment

Answer 1

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.

Chronology

I have an application that stores lots of small files (about 1k) on EFS, and I see read latencies in the range of 2ms to 4ms. It's kinda like a magnetic hard drive instead of an SSD. – Gopherwood

Answer 2

As Chris pointed out, EFS is not the most performant solution. Another option would be to use FSx for NetApp ONTAP. It is a managed service like EFS, however, it is not as expensive and is much more performant, by providing sub-millisecond latency. It also supports a Multi AZ deployment, with automatically transparent failover.

Regarding performance, EFS maxes out at 1.500 MiBps per client throughput, whereas FSxN can get up to 4GB/s.

Colier

Answer 3

EFS is a Network Filesystem(NFS). It provides a file system interface, file system access semantics (such as strong consistency and file locking), and concurrently-accessible storage for up to thousands of Amazon EC2 instances. Ofcourse there would be read/write latency compared to EBS as EBS is designed for low-latency access to data.

EBS provides different volume types, which differ in performance characteristics and price, so that you can tailor your storage performance and cost to the needs of your applications.

EFS is easy to use and offers a simple interface that allows you to create and configure file systems quickly and easily. With Amazon EFS, storage capacity is elastic, growing and shrinking automatically as you add and remove files, so your applications have the storage they need, when they need it.

Perfromance Overview of EFS: http://docs.aws.amazon.com/efs/latest/ug/performance.html

Performance Overview of EBS:http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html

Metathesis