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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

#321

Post by kristopolous »

esafak wrote: post #300
kristopolous wrote: post #286

Earlier quoted context omitted.

You aren't going to get there. The risks and complexity of a startup are high to begin with. Adding artificial roadblocks because of aspirational fantasies is going to hold you back. Look at the big successes such as youtube, twitter, facebook, airbnb, lyft, google, yahoo - exactly zero of them did this preventatively. Even altavista and babelfish, done by DEC and running on Alphas, which they had plenty of, had to b…

Do you remember the companies that did not scale? friendster did well until it failed to scale, and Facebook took over. So the converse argument might be: don't bungle it up because you failed to plan. Provision for at least 10x growth with every (re-)implementation. https://highscalability.com/friendster-lost-lead-because-of-...

Hold on... You think Facebook took over from Friendster because of scaling problems?!

MySpace was the one that took the lead over Friendster and it withered after it got acquired for $500 million by news corp because that was the liquidity event. That's when Facebook gained ground. Your timeline is wrong.

The MySpace switch was because of themes and other features the users found more appealing. Twitter had similar crashes with its fail whale for a long time and they survived it fine. The teen exodus of Friendster wasn't because of TTLB waterfall graphs.

Also MySpace did everything on cheap Microsoft IIS 6 servers in ASP 2.0 after switching from Coldfusion in Macromedia HomeSite, they weren't genuises. It was a knockoff created by amateurs with a couple new twists. (A modern clone has 2.5 mil users: see https://spacehey.com/browse still mostly teenagers)

Besides, when the final Friendster holdout of the Asian market had exponential decline in 2008, the scaling problems of 5 years ago had long been fixed. Faster load times did not make up for a product consumers no longer found compelling.

Also Facebook initially was running literally out of Mark's dorm room. In 2007, after they had won the war, their code got leaked because they were deploying the .svn directory in their deploy strategy. Their code was widely mocked. So there we are again.

I don't care if you can find someone who agrees with you on the Friendster scaling thing, almost every collapsed startup has someone that says "we were just too successful and couldn't keep up" because thinking you were just too awesome is the gentler on the ego than realizing a bunch of scrappy hackers just gave people more of what they wanted and either you didn't realize it or you thought your lack of adaption was a virtue.

Re: SSDs have become fast, except in the cloud

#322

Post by phanimahesh »

wmf wrote: post #260
wstuartcl wrote: post #226

Earlier quoted context omitted.

the tests were for these local (metal direct connect ssds). The issue is not network overhead -- its that just like everything else in cloud the performance of 10 years ago was used as the baseline that carries over today with upcharges to buy back the gains. there is a reason why vcpu performance is still locked to the typical core from 10 years ago when every core on a machine today in those data scenters is 3-5x o…

vcpu performance is still locked to the typical core from 10 years ago No. In some cases I think AWS actually buys special processors that are clocked higher than the ones you can buy.

The parent claims that though aws uses better hardware, they bill in vcpus whose benchmarks are from a few years ago, so that they can sell more vcpu units per performant physical cpu. This does not contradict your claim that aws buys better hardware.

Re: SSDs have become fast, except in the cloud

#323

Post by kuchenbecker »

aarmenaa wrote: post #175
echelon wrote: post #17

Earlier quoted context omitted.

The reasons to switch away from cloud keep piling up. We're doing some amount of on-prem, and I'm eager to do more.

I've previously worked for a place that ran most of their production network "on-prem". They had a few thousand physical machines spread across 6 or so colocation sites on three continents. I enjoyed that job immensely; I'd jump at the chance to build something like it from the ground up. I'm not sure if that actually makes sense for very many businesses though.

I'm getting that opportunity, however I expect it will be the last as most have migrated to the cloud and smaller companies are appealing to me; smallest company (of 5) I've worked for had 4.4k employees and large companies have the resources to roll their own.

Unless there is an onprem movement I expect cloud to be the future as maintaining the tech stack onprem is difficult and we need to nake decisions down to the hardware we order.

Re: SSDs have become fast, except in the cloud

#324

Post by stingraycharles »

jasonwatkinspdx wrote: post #221
pclmulqdq wrote: post #143

Earlier quoted context omitted.

That's the abstraction they want you to work with, yes. That doesn't mean it's what is actually happening - at least not in the same way that you're thinking. As a hint for you, I said " a network", not " the network." You can also look at public presentations about how Nitro works.

Both the documentation and Amazon employees are in here telling you that you're wrong. Can you resolve that contradiction or do you just want to act coy like you know some secret? The latter behavior is not productive.

The parent thinks that AWS' i3 NVMe local instance storage is using a PCIe switch, which is not the case. EBS (and the AWS Nitro card) use a PCIe switch, and as such all EBS storage is exposed as e.g. /dev/nvmeXnY . But that's not the same as the i3 instances are offering, so the parent is confused.

Re: SSDs have become fast, except in the cloud

#325

Post by flaminHotSpeedo »

wstuartcl wrote: post #226
jsnell wrote: post #71

Earlier quoted context omitted.

I think you're wrong about that. AWS calls this class of storage "instance storage" [0], and defines it as: > Many Amazon EC2 instances can also include storage from devices that are located inside the host computer, referred to as instance storage. There might be some wiggle room in "physically attached", but there's none in "storage devices located inside the host computer". It's not some kind of AWS-only thing eit…

the tests were for these local (metal direct connect ssds). The issue is not network overhead -- its that just like everything else in cloud the performance of 10 years ago was used as the baseline that carries over today with upcharges to buy back the gains. there is a reason why vcpu performance is still locked to the typical core from 10 years ago when every core on a machine today in those data scenters is 3-5x o…

> there is a reason why vcpu performance is still locked to the typical core from 10 years ago

That is transparently nonsense.

You can disprove that claim in 5 minutes, and it makes literally zero sense for offerings that aren't oversubscribed

Re: SSDs have become fast, except in the cloud

#326

Post by flaminHotSpeedo »

mike_hearn wrote: post #134
ianburrell wrote: post #118

Earlier quoted context omitted.

The reason for having most instances use network storage is that it makes possible migrating instances to other hosts. If the host fails, the network storage can be pointed at the new host with a reboot. AWS sends out notices regularly when they are going to reboot or migrate instances. Their probably should be more local instance storage types for using with instances that can be recreated without loss. But it is si…

Sure, I understand that, but this user is claiming that on GCP even local SSDs aren't really local, which raises the question of why not. I suspect the answer is something to do with their manufacturing processes/rack designs. When I worked there (pre GCP) machines had only a tiny disk used for booting and they wanted to get rid of that. Storage was handled by "diskful" machines that had dedicated trays of HDDs conne…

They're claiming so, but they're wrong.

Re: SSDs have become fast, except in the cloud

#327

Post by CoolCold »

vitus wrote: post #263
scottlamb wrote: post #188

Earlier quoted context omitted.

Again, I'm not talking about spikes (though better tail latency is always desirable) but poor latency in the 50%ile case. And for high-QoS applications, not batch stuff. The snap paper linked elsewhere in the thread shows 10 µs latencies; they've put in some optimization to achieve that, but I don't really understand why we don't expect close to that with standard kernel networking and TCP.

> The snap paper linked elsewhere in the thread shows 10 µs latencies; they've put in some optimization to achieve that, but I don't really understand why we don't expect close to that with standard kernel networking and TCP. You can get similar results by looking at comparisons between DPDK and kernel networking. Most of the usual gap comes from not needing to context-switch for kernel interrupt handling, zero-copy…

Great reading, thanks for the link on vanilla vs dpdk

Re: SSDs have become fast, except in the cloud

#328

Post by hypercube33 »

bcaxis wrote: post #302
tumult wrote: post #288

Earlier quoted context omitted.

My experience lately is that consumer drives will also lie and use a cache, but then drop your data on the floor if the power is lost or there’s a kernel panic / BSOD. (Samsung and others.)

Rumors of that. I've never actually seen it myself.

Only thing I ever have seen is some cheap Samsung drives slow to a crawl when their buffer fills or those super old Intel ssds that power loss to 8mb due to some firmware bug.

Re: SSDs have become fast, except in the cloud

#329

Post by wmf »

phanimahesh wrote: post #322
wmf wrote: post #260

Earlier quoted context omitted.

vcpu performance is still locked to the typical core from 10 years ago No. In some cases I think AWS actually buys special processors that are clocked higher than the ones you can buy.

The parent claims that though aws uses better hardware, they bill in vcpus whose benchmarks are from a few years ago, so that they can sell more vcpu units per performant physical cpu. This does not contradict your claim that aws buys better hardware.

It's so obviously wrong that I can't really explain it. Maybe someone else can. To believe that requires a complete misunderstanding of IaaS.

Re: SSDs have become fast, except in the cloud

#330

Post by flaminHotSpeedo »

nine_k wrote: post #269
Twirrim wrote: post #57

Disclaimer: I work for OCI, opinion my own etc. We offer faster NVMe drives in instances. Our E4 Dense shapes ship with SAMSUNG MZWLJ7T6HALA-00AU3, which supports Sequential Reads of 7000 MB/s, and Sequential Write 3800 MB/s. From a general perspective, I would say the _likely_ answer to why AWS doesn't have faster NVMes at the moment is likely to be lack of specific demand. That's a guess, but that's generally how t…

I very much expect AWS SSD / NVMe upgrades to be well thought-out ahead of time, and optimized for both upfront cost and for longevity / durability. Speed may be a third consideration.

Yeah, hardware and forecasting for cloud providers is basically the definition of deliberate.

If anything I'd guess it's a procurement issue, parity between regions is a big thing and it's hard to supply dozens of regions around the world with the latest hardware hotness

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