The lifeblood of any online retailer is the speed of its IT infrastructure. Shoppers aren’t infinitely patient. Sluggish infrastructure performance can make shoppers wait precious seconds longer than they can stand, sending them fleeing to other sites for a faster purchase. Our federal government’s halting rollout of the Health Insurance Marketplace website is a glaring example of what can happen when IT infrastructure isn’t solid. A few bad user experiences that go viral can be damaging enough. Tens of thousands can be crippling.
In hyperscale datacenters, any number of problems including network issues, insufficient scaling and inconsistent management can undermine end users’ experience. But one that hits home for me is the impact of slow storage on the performance of databases, where the data sits. With the database at the heart of all those online transactions, retailers can ill afford to have their tier of database servers operating at anything less than peak performance.
Slow storage undermines database performance
Typically, Web 2.0 and e-commerce companies run relational databases (RDBs) on these massive server-centric infrastructures. (Take a look at my blog last week to get a feel for the size of these hyperscale datacenter infrastructures). If you are running that many servers to support millions of users, you are likely using some kind of open-sourced RDB such as MySQL or other variations. Keep in mind that Oracle 11gR2 likely retails around $30K per core but MSQL is free. But the performance of both, and most other relational databases, suffer immensely when transactions are retrieving data from storage (or disk). You can only throw so much RAM and CPU power at the performance problem … sooner rather than later you have to deal with slow storage.
Almost everyone in industry – Web 2.0, cloud, hyperscale and other providers of massive database infrastructures – is lining up to solve this problem the best way they can. How? By deploying flash as the sole storage for database servers and applications. But is low-latency flash enough? For sheer performance it beats rotational disk hands down. But … even flash storage has its limitations, most notably when you are trying to drive ultra-low latencies for write IOs. Most IO accesses by RDBs, which do the transactional processing, are a mix or read/writes to the storage. Specifically, the mix is 70%/30% reads/writes. These are also typically low q-depth accesses (less than 4). It is those writes that can really slow things down.
PCIe flash reduces write latencies
The good news is that the right PCIe flash technology in the mix can solve the slowdowns. Some interesting PCIe flash technologies designed to tackle this latency problem are on display at AIS this week. DRAM and in particular NVDRAM are being deployed as a tier in front of flash to really tackle those nasty write latencies.
Among other demos, we’re showing how a Nytro™ 6000 series PCIe flash card helps solve the MySQL database performance issues. The typical response time for a small data read (this is what the database will see for a Database IO) from an HDD is 5ms. Flash-based devices such as the Nytro WarpDrive® card can complete the same read in less than 50μs on average during testing, an improvement of several orders-of-magnitude in response time. This response time translates to getting much higher transactions out of the same infrastructure – but with less space (flash is denser) and a lot less power (flash consumes a lot lower power than HDDs).
We’re also showing the Nytro 7000 series PCIe flash cards. They reach even lower write latencies than the 6000 series and very low q-depths. The 7000 series cards also provide DRAM buffering while maintaining data-integrity even in the event of a power loss.
For online retailers and other businesses, higher database speeds mean more than just faster transactions. They can help keep those cash registers ringing.
Tags: AIS, database, DRAM, e-commerce, flash, flash memory, hard disk drive, HDD, hyperscale datacenter, latency, MySQL, NVDRAM, Nytro 6000, Nytro 7000, Nytro WarpDrive, Oracle, PCIe flash, relational database, storage latency, web 2.0, write latency
You might be surprised to find out how big the infrastructure for cloud and Web 2.0 is. It is mind-blowing. Microsoft has acknowledged packing more than 1 million servers into its datacenters, and by some accounts that is fewer than Google’s massive server count but a bit more than Amazon.
Facebook’s server count is said to have skyrocketed from 30,000 in 2012 to 180,000 just this past August, serving 900 million plus users. And the social media giant is even putting its considerable weight behind the Open Compute effort to make servers fit better in a rack and draw less power. The list of mega infrastructures also includes Tencent, Baidu and Alibaba and the roster goes on and on.
Even more jaw-dropping is that almost 99.9% of these hyperscale infrastructures are built with servers featuring direct-attached storage. That’s right – they do the computing and store the data. In other words, no special, dedicated storage gear. Yes, your Facebook photos, your Skydrive personal cloud and all the content you use for entertainment, on-demand video and gaming data are stored inside the server.
Direct-attached storage reigns supreme
Everything in these infrastructures – compute and storage – is built out of x-86 based servers with storage inside. What’s more, growth of direct-attached storage is many folds bigger than any other storage deployments in IT. Rising deployments of cloud, or cloud-like, architectures are behind much of this expansion.
The prevalence of direct-attached storage is not unique to hyperscale deployments. Large IT organizations are looking to reap the rewards of creating similar on-premise infrastructures. The benefits are impressive: Build one kind of infrastructure (server racks), host anything you want (any of your properties), and scale if you need to very easily. TCO is much less than infrastructures relying on network storage or SANs.
With direct-attached you no longer need dedicated appliances for your database tier, your email tier, your analytics tier, your EDA tier. All of that can be hosted on scalable, share-nothing infrastructure. And just as with hyperscale, the storage is all in the server. No SAN storage required.
Open Compute, OpenStack and software-defined storage drive DAS growth
Open Compute is part of the picture. A recent Open Compute show I attended was mostly sponsored by hyperscale customers/suppliers. Many big-bank IT folks attended. Open Compute isn’t the only initiative driving growing deployments of direct-attached storage. So is software-defined storage and OpenStack. Big application vendors such as Oracle, Microsoft, VMware and SAP are also on board, providing solutions that support server-based storage/compute platforms that are easy and cost-effective to deploy, maintain and scale and need no external storage (or SAN including all-flash arrays).
So if you are a network-storage or SAN manufacturer, you have to be doing some serious thinking (many have already) about how you’re going to catch and ride this huge wave of growth.
Tags: Alibaba, Amazon, Baidu, cloud computing, DAS, direct attached storage, enterprise, enterprise IT, Google, hyperscale, Microsoft, Open Compute, OpenStack, Oracle, SAP, Tencent, VMware
I was lucky enough to get together for dinner and beer with old friends a few weeks ago. Between the 4 of us, we’ve been involved in or responsible for a lot of stuff you use every day, or at least know about.
Supercomputers, minicomputers, PCs, Macs, Newton, smart phones, game consoles, automotive engine controllers and safety systems, secure passport chips, DRAM interfaces, netbooks, and a bunch of processor architectures: Alpha, PowerPC, Sparc, MIPS, StrongARM/XScale, x86 64-bit, and a bunch of other ones you haven’t heard of (um – most of those are mine, like TriCore). Basically if you drive a European car, travel internationally, use the Internet , if you play video games, or use a smart phone, well… you’re welcome.
Why do I tell you this? Well – first I’m name dropping – I’m always stunned I can call these guys friends and be their peers. But more importantly, we’ve all been in this industry as architects for about 30 years. Of course our talk went to what’s going on today. And we all agree that we’ve never seen more changes – inflexions – than the raft unfolding right now. Maybe its pressure from the recession, or maybe un-naturally pent up need for change in the ecosystem, but change there is.
Changes in who drives innovation, what’s needed, the companies on top and on bottom at every point in the food chain, who competes with whom, how workloads have changed from compute to dataflow, software has moved to opensource, how abstracted code is now from processor architecture, how individual and enterprise customers have been revolting against the “old” ways, old vendors, old business models, and what the architectures look like, how processors communicate, and how systems are purchased, and what fundamental system architectures look like. But not much besides that…
Ok – so if you’re an architect, that’s as exciting as it gets (you hear it in my voice – right ?), and it makes for a lot of opportunities to innovate and create new or changed businesses. Because innovation is so often at the intersection of changing ways of doing things. We’re at a point where the changes are definitely not done yet. We’re just at the start. (OK – now try to imagine a really animated 4-way conversation over beers at the Britannia Arms in Cupertino… Yea – exciting.)
I’m going to focus on just one sliver of the market – but it’s important to me – and that’s enterprise IT. I think the changes are as much about business models as technology.
Hyperscale datacenters drive innovation
I’ll start in a strange place. Hyperscale datacenters (think social media, search, etc.) and the scale of deployment changes the optimization point. Most of us starting to get comfortable with rack as the new purchase quantum. And some of us are comfortable with the pod or container as the new purchase quantum. But the hyperscale dataenters work more at the datacenter as the quantum. By looking at it that way, they can trade off the cost of power, real estate, bent sheet metal, network bandwidth, disk drives, flash, processor type and quantity, memory amount, where work gets done, and what applications are optimized for. In other words, we shifted from looking at local optima to looking for global optima. I don’t know about you, but when I took operations research in university, I learned there was an unbelievable difference between the two – and global optima was the one you wanted…
Hyperscale datacenters buy enough (top 6 are probably more than 10% of the market today) that 1) they need to determine what they deploy very carefully on their own, and 2) vendors work hard to give them what they need.
That means innovation used to be driven by OEMs, but now it’s driven by hyperscale datacenters and it’s driven hard. That global optimum? It’s work/$ spent. That’s global work, and global spend. It’s OK to spend more, even way more on one thing if over-all you get more done for the $’s you spend.
That’s why the 3 biggest consumers of flash in servers are Facebook, Google, and Apple, with some of the others not far behind. You want stuff, they want to provide it, and flash makes it happen efficiently. So efficiently they can often give that service away for free.
Hyperscale datacenters have started to publish their cost metrics, and open up their architectures (like OpenCompute), and open up their software (like Hadoop and derivatives). More to the point, services like Amazon have put a very clear $ value on services. And it’s shockingly low.
Enterprises are paying attention
Enterprises have looked at those numbers. Hard. That’s catalyzed a customer revolt against the old way of doing things – the old way of buy and billing. OEMs and ISVs are creating lots of value for enterprise, but not that much. They’ve been innovating around “stickiness” and “lock-in” (yea – those really are industry terms) for too long, while hyperscale datacenters have been focused on getting stuff done efficiently. The money they save per unit just means they can deploy more units and provide better services.
That revolt is manifesting itself in 2 ways. The first is seen in the quarterly reports of OEMs and ISVs. Rumors of IBM selling its X-series to Lenovo, Dell going private, Oracle trying to shift business, HP talking of the “new style of IT”… The second is enterprises are looking to emulate hyperscale datacenters as much as possible, and deploy private cloud infrastructure. And often as not, those will be running some of the same open source applications and file systems as the big hyperscale datacenters use.
Where are the hyperscale datacenters leading them? It’s a big list of changes, and they’re all over the place.
But they’re also looking at a few different things. For example, global name space NAS file systems. Personally? I think this one’s a mistake. I like the idea of file systems/object stores, but the network interconnect seems like a bottleneck. Storage traffic is shared with network traffic, creates some network spine bottlenecks, creates consistency performance bottlenecks between the NAS heads, and – let’s face it – people usually skimp on the number of 10GE ports on the server and in the top of rack switch. A typical SAS storage card now has 8 x 12G ports – that’s 96G of bandwidth. Will servers have 10 x 10G ports? Yea. I didn’t think so either.
Anyway – all this is not academic. One Wall Street bank shared with me that – hold your breath – it could save 70% of its spend going this route. It was shocked. I wasn’t shocked, because at first blush this seems absurd – not possible. That’s how I reacted. I laughed. But… The systems are simpler and less costly to make. There is simply less there to make or ship than OEMs force into the machines for uniqueness and “value.” They are purchased from much lower margin manufacturers. They have massively reduced maintenance costs (there’s less to service, and, well, no OEM service contracts). And also important – some of the incredibly expensive software licenses are flipped to open source equivalents. Net savings of 70%. Easy. Stop laughing.
Disaggregation: Or in other words, Pooled Resources
But probably the most important trend from all of this is what server manufacturers are calling “disaggregation” (hey – you’re ripping apart my server!) but architects are more descriptively calling pooled resources.
First – the intent of disaggregation is not to rip the parts of a server to pieces to get lowest pricing on the components. No. If you’re buying by the rack anyway – why not package so you can put like with like. Each part has its own life cycle after all. CPUs are 18 months. DRAM is several years. Flash might be 3 years. Disks can be 5 to 7 years. Networks are 5 to 10 years. Power supplies are… forever? Why not replace each on its own natural failure/upgrade cycle? Why not make enclosures appropriate to the technology they hold? Disk drives need solid vibration-free mechanical enclosures of heavy metal. Processors need strong cooling. Flash wants to run hot. DRAM cool.
Second – pooling allows really efficient use of resources. Systems need slush resources. What happens to a systems that uses 100% of physical memory? It slows down a lot. If a database runs out of storage? It blue screens. If you don’t have enough network bandwidth? The result is, every server is over provisioned for its task. Extra DRAM, extra network bandwidth, extra flash, extra disk drive spindles.. If you have 1,000 nodes you can easily strand TBytes of DRAM, TBytes of flash, a TByte/s of network bandwidth of wasted capacity, and all that always burning power. Worse, if you plan wrong and deploy servers with too little disk or flash or DRAM, there’s not much you can do about it. Now think 10,000 or 100,000 nodes… Ouch.
If you pool those things across 30 to 100 servers, you can allocate as needed to individual servers. Just as importantly, you can configure systems logically, not physically. That means you don’t have to be perfect in planning ahead what configurations and how many of each you’ll need. You have sub-assemblies you slap into a rack, and hook up by configuration scripts, and get efficient resource allocation that can change over time. You need a lot of storage? A little? Higher performance flash? Extra network bandwidth? Just configure them.
That’s a big deal.
And of course, this sets the stage for immense pooled main memory – once the next generation non-volatile memories are ready – probably starting around 2015.
You can’t underestimate the operational problems associated with different platforms at scale. Many hyperscale datacenters today have around 6 platforms. If you think they are rolling out new versions of those before old ones are retired they often have 3 generations of each. That’s 18 distinct platforms, with multiple software revisions of each. That starts to get crazy when you may have 200,000 to 400,000 servers to manage and maintain in a lights out environment. Pooling resources and allocating them in the field goes a huge way to simplifying operations.
Alternate Processor Architecture
It didn’t always used to be Intel x86. There was a time when Intel was an upstart in the server business. It was Power, MIPs, Alpha, SPARC… (and before that IBM mainframes and minis, etc). Each of the changes was brought on by changing the cost structure. Mainframes got displaced by multi-processor RISC, which gave way to x86.
Today, we have Oracle saying they’re getting out of x86 commodity servers and doubling down on SPARC. IBM is selling off its x86 business and doubling down on Power (hey – don’t confuse that with PowerPC – which started as an architectural cut-down of Power – I was there…). And of course there is a rash of 64-bit ARM server SOCs coming – with HP and Dell already dabbling in it. What’s important to realize is that all of these offerings are focusing on the platform architecture, and how applications really perform in total, not just the processor.
Let me warp up with an email thread cut/paste from a smart friend – Wayne Nation. I think he summed up some of what’s going on well, in a sobering way most people don’t even consider.
“Does this remind you of a time, long ago, when the market was exploding with companies that started to make servers out of those cheap little desktop x86 CPUs? What is different this time? Cost reduction and disaggregation? No, cost and disagg are important still, but not new.
A new CPU architecture? No, x86 was “new” before. ARM promises to reduce cost, as did Intel.
Disaggregation enables hyperscale datacenters to leverage vanity-free, but consistent delivery will determine the winning supplier. There is the potential for another Intel to rise from these other companies. “