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SSDs have become fast, except in the cloud

databasearchitects.blogspot.com

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Re: SSDs have become fast, except in the cloud

#421

Post by bmicraft »

seabrookmx wrote: post #420
bmicraft wrote: post #419

Earlier quoted context omitted.

What this tells me is that the price of running inefficient cpus seemingly isn't nearly as high as I thought it would or should be (in terms of usd/kWh)

Well they bill you for the instance not for some unit of computation. I'd imagine many users of E2 instances don't realize that they could be getting much much worse performance per vcore than if they picked a different instance type. From Google's perspective, if the hardware is paid for, still reliable, and they can still make money on it, they can put new hardware in new racks rather than replacing the old hardwar…

Well not exactly. In my mind the price of running such old cpus for say the last (say, 4?) years would have been higher than buying new+new runtime costs. Those would definitely be considered opportunity costs that ought to be avoided.

Re: SSDs have become fast, except in the cloud

#422

Post by redwood »

_Rabs_ wrote: post #15
pclmulqdq wrote: post #11

This was a huge technical problem I worked on at Google, and is sort of fundamental to a cloud. I believe this is actually a big deal that drives peoples' technology directions. SSDs in the cloud are attached over a network, and fundamentally have to be. The problem is that this network is so large and slow that it can't give you anywhere near the performance of a local SSD. This wasn't a problem for hard drives, whi…

So much of this. The amount of times I've seen someone complain about slow DB performance when they're trying to connect to it from a different VPC, and bottlenecking themselves to 100Mbits is stupidly high. Literally depending on where things are in a data center... If you're looking for closely coupled and on a 10G line on the same switch, going to the same server rack. I bet you performance will be so much more co…

Your comment implies that a network hop between two VPCs is inherently slow. My understanding is the VPCs are akin to a network encryption isolation boundary but should not meaningfully slow down network transfers between each other..

I think you may be conflating the fact that across two VPCs you may be slightly more likely to be doing a cross availability zone or potentially even cross region network hop? I just think it's important to be on the pulse of what's really going on here

Re: SSDs have become fast, except in the cloud

#423

Post by seabrookmx »

bmicraft wrote: post #421
seabrookmx wrote: post #420

Earlier quoted context omitted.

Well they bill you for the instance not for some unit of computation. I'd imagine many users of E2 instances don't realize that they could be getting much much worse performance per vcore than if they picked a different instance type. From Google's perspective, if the hardware is paid for, still reliable, and they can still make money on it, they can put new hardware in new racks rather than replacing the old hardwar…

Well not exactly. In my mind the price of running such old cpus for say the last (say, 4?) years would have been higher than buying new+new runtime costs. Those would definitely be considered opportunity costs that ought to be avoided.

> the price of running such old cpus for say the last (say, 4?) years would have been higher than buying new+new runtime costs

I don't think this is true, because the old chips don't use more power outright[1][2][3]. In fact in many cases new chips use more power due to the higher core density. The new chips are way more efficient because they do more work per watt, but like I said in my previous comment you aren't paying for a unit of work. The billing model for the cloud providers is that of a rental: you pay per minute for the instance.

There's complexity here like being able to pack more "instances" (VM's) onto a physical host with the higher core count machines, but simply saying the new hardware is cheaper to run I don't think is clear cut.

[1]: https://cloud.google.com/compute/docs/cpu-platforms#intel_pr...

[2]: https://www.intel.com/content/www/us/en/products/sku/93792/i...

[3]: https://www.intel.com/content/www/us/en/products/sku/231746/...

Re: SSDs have become fast, except in the cloud

#424

Post by singleshot_ »

driftnet wrote: post #379
arrakeenrevived wrote: post #299

Earlier quoted context omitted.

Clouds (like, the big fluffy things in the sky) are made up of many droplets of liquid. Using "droplet" to refer to the things that make up cloud computing is a pretty natural nickname for any cloud provider, not just DO. I do imagine that DO uses "droplet" as a public product branding because it works well with their "Ocean" brand, though. ...now I'm actually interested in knowing if "droplet" is derived from "ocean…

Clouds are water vapor, not droplets.

Clouds are condensed water droplets in the air. The air below the cloud has just about the same amount of water in it, but at the altitude of the bottom of the cloud, the atmosphere is cool enough for that water vapor to condense, forming the cloud.

Search terms include “lapse rate” if you would like to learn more.

Re: SSDs have become fast, except in the cloud

#425

Post by bmicraft »

seabrookmx wrote: post #423
bmicraft wrote: post #421

Earlier quoted context omitted.

Well not exactly. In my mind the price of running such old cpus for say the last (say, 4?) years would have been higher than buying new+new runtime costs. Those would definitely be considered opportunity costs that ought to be avoided.

> the price of running such old cpus for say the last (say, 4?) years would have been higher than buying new+new runtime costs I don't think this is true, because the old chips don't use more power outright[1][2][3]. In fact in many cases new chips use more power due to the higher core density. The new chips are way more efficient because they do more work per watt, but like I said in my previous comment you aren't p…

True, although they could very well do upgrades on the kind of VPS' where they were already oversubscribed. If you're not paying for physical cores I don't think that argument works.

Re: SSDs have become fast, except in the cloud

#426

Post by highfrequency »

sprachspiel wrote: post #88
nik_0_0 wrote: post #75

Earlier quoted context omitted.

Is it? The line preceding the bullet list on that page seems to state otherwise: “” Each storage volume can deliver the following performance (all measured using 4 KiB blocks): * Up to 8000 MB/second of sequential reads “”

Just tested a i4i.32xlarge: $ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS loop0 7:0 0 24.9M 1 loop /snap/amazon-ssm-agent/7628 loop1 7:1 0 55.7M 1 loop /snap/core18/2812 loop2 7:2 0 63.5M 1 loop /snap/core20/2015 loop3 7:3 0 111.9M 1 loop /snap/lxd/24322 loop4 7:4 0 40.9M 1 loop /snap/snapd/20290 nvme0n1 259:0 0 8G 0 disk ├─nvme0n1p1 259:1 0 7.9G 0 part / ├─nvme0n1p14 259:2 0 4M 0 part └─nvme0n1p15 259:3 0 106M 0…

The aggregate throughput matches the advertised number of 22,400 MB/s: https://aws.amazon.com/blogs/aws/new-storage-optimized-amazo...

Re: SSDs have become fast, except in the cloud

#427

Post by seabrookmx »

bmicraft wrote: post #425
seabrookmx wrote: post #423

Earlier quoted context omitted.

> the price of running such old cpus for say the last (say, 4?) years would have been higher than buying new+new runtime costs I don't think this is true, because the old chips don't use more power outright[1][2][3]. In fact in many cases new chips use more power due to the higher core density. The new chips are way more efficient because they do more work per watt, but like I said in my previous comment you aren't p…

True, although they could very well do upgrades on the kind of VPS' where they were already oversubscribed. If you're not paying for physical cores I don't think that argument works.

Sure but my comment was about Google's E2 instances specifically, which are billed this way. For Cloud Run or the Google Services they host, I agree it would be odd for them to use old chips given the inefficiency.
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