Hacker News Reader

Comment by fb03 | Hacker News Reader

Has anyone here made the jump? I'm considering testing some components or our infrastructure on Gravitron processors but going all the way in with the database sounds risky but I don't really have a technical data point to justify my bias.

View on HN

I made the jump on one of my databases soon after Graviton 2 was officially supported on RDS. I'm running a small (~500 GB stored data) DB on db.m6g.large with PG 12.4. It's a tiny bit cheaper and performs modestly better than the Intel based instance it was running on before. There haven't been any problems or externally visible changes since the switch.

We did is and is amazing! All the claims are true and worth it. If your stack is Linux Based you can be up and running within hours: Our stack is based on NodeJS, PostgreSQL, Nginx, Redis, MongoDB, MySQL

FWIW, our experience was different: I benchmarked our Node apps on C6g, C5n, and M5zn and found Graviton to be 10-25% slower in our CPU-bound NodeJS code than the same code on x86. Graviton give you better relative performance per dollar, but for absolute single-thread performance M5zn is still the best choice for us.

Arguably, if you're using AWS, you've already compromised to a point where scaling horizontally is your path forward.

You've likely given up much more than 10-25% by using AWS in the first place (note to the false dichotomist: this doesn't mean owning your own servers). And paid a premium for the privilege.

If you're CPU-bound, get a E-2288G (or whatever the commodity chip that maximized price/$$ is right now) and set mitigations=off.

Which cloud providers are better? What do you use?

I think Google Cloud requires less domain-specific-knowledge, which is a big plus. And, as a consequence, you're less likely to end up with an expensive and complicated mess.

But if price or performance or user privacy is a concern, none.

I'm a big believe in dedicated hosting. There's tens of thousands of options. Not affiliated with any, but in the past/present what I have/am using and would recommend: webnx.com, reliablesite.net, hivelocity.com, hetzner.com, ovh.com (and their other brands), leaseweb.com we're currently considering phoenixnap.com for a warm-standby DR site (but no experience with them yet). Also, Softlayer pre-IBM acquisition, but that's just sour grapes.

Depending on your specific needs, then Hetzner seems to be good value:

https://www.hetzner.com/dedicated-rootserver/matrix-ax

They have a good reputation for stability too, unlike (say) Scaleway. ;)

Mitigations=off?

I’m going to assume it’s the Intel HyperThreading exploit mitigations?

Yes, starting with Linux 5.2, a bunch of mitigations can be disabled with that 1 boot option. But that's just a small part of where the performance gain comes from. The real win is just recent, dedicated and non-virtualized hardware.

I moved ElastiCache & RDS instances over. A bit faster, a bit cheaper exactly as expected and no time required other than a “terraform apply”.

I’ve played with graviton instances and compiled a few bits of C I use for benchmarking. Not a scientific test but I found them to be good but nowhere near the performance per core as the intel offerings. As a comparison they are nowhere near the Apple M1 either. But that doesn’t mean they’re a bad option.

I think they end up close to same price/performance as the Intel offerings as well once you invoke the compiler optimiser. The main benefit is better core scalability and lower energy usage which may work out as a net gain for database workloads.

As always it’s best to measure these things yourself with your expected workload.

Gravitron's value prop is you get 2x the physical cores for a slightly cheaper price. Intel wins at single-thread performance, but for parallel workloads Intel's hyperthreaded vCPUs can't keep up.

But you're right in that in the end it all depends on your workload.

I use it with RDS. If something fucks up, you can always blame AWS. Otherwise have had no issues with it.

For my side projects waiting for them to do the burstable / cheaper versions in RDS. It's a bit funny that the cheaper chip is not available in the cheaper instance options - seems like that would be a good market (whoever is too cheap to do M instances etc).

Edit: T4g's are available on EC2.

https://blog.aawadia.dev/2021/01/06/upgrading-pg-10-to-12/ wrote a bit about it

> Has anyone here made the jump?

Waiting for the t4 instances.

Uh, they've been available for several months now.

https://aws.amazon.com/blogs/aws/new-t4g-instances-burstable...

Not for RDS (or beanstalk).

Reply on news.ycombinator.com