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> With the in house server you need at least two, in case one fails. That doesn't really change much when the difference is a four figure sum spread over five

by zrm 7y ago

> With the in house server you need at least two, in case one fails. That doesn't really change much when the difference is a four figure sum spread over five years. > Then you need someone to plan, provision, troubleshoot, and maintain the physical servers. So at best a full time fully loaded position which costs the company roughly 2x the salary. Would it really take a full time position to maintain two physical servers? That's a day or two for initial installation and configuration which gets amortized over the full lifetime, OS updates managed by the same system you need in any case for the guests, maybe an hour a year if you get a power supply or drive failure. If the maintenance on two physical machines add up to a full week out of the year for the person already maintaining the guests, something has gone terribly wrong. Which itself gets balanced against the time it would take the same person to configure and interact with the cloud vendor's provisioning system -- probably not a huge difference in the time commitment. > And that's only if you know your workload so well that you can guarantee the shape of your hardware usage 3-5 years out. Rarely possible in practice. Most companies will do about the same business this year as they did last year plus or minus a few percent, so it's really the common case. And if you unexpectedly grow 200% one year then you use some of that unexpected revenue to buy a third server. Where the scalability could really help is if you could grow 200,000% overnight, but that's not really a relevant scenario to your average company operating a shopping mall or a steel mill.

eloff 7y ago
Certainly if you have someone already on the payroll who can take responsibility for the hardware part time, that makes it a lot cheaper. That's a different skill set though, so it's not true for every company. With respect to changing workloads, I wasn't thinking so much about scale, which I think isn't that hard to plan for, but more about changing requirements. If you add, remove, or change a piece of your stack the cloud gives a lot of flexibility. Add memcached, no problem, spin up some high mem instances. Need more IO on the database server, switch to an instance with fast SSDs, or a bigger instance. I think those kinds of changes are common and hard to plan for. Until it happens you probably don't know if you are disk, network, memory, or CPU bound. Once your stack is sufficiently mature and not changing much the workload gets a lot more predictable. The cloud is really good for starting out. The danger is it's also really good at locking you in, then you are stuck with it.
- zrm 7y ago
  > Certainly if you have someone already on the payroll who can take responsibility for the hardware part time, that makes it a lot cheaper. That's a different skill set though, so it's not true for every company. True, though all the physical hardware stuff is pretty straight forward, to the point that anybody competent could figure it out in real time just by looking at the pictures in the manual. Configuring a hypervisor is the main thing you actually have to learn, and that's a fundamentally similar skillset to systems administration for the guests. Or for that matter the cloud vendor's provisioning interface. It's just different tooling. > If you add, remove, or change a piece of your stack the cloud gives a lot of flexibility. Add memcached, no problem, spin up some high mem instances. Need more IO on the database server, switch to an instance with fast SSDs, or a bigger instance. I think those kinds of changes are common and hard to plan for. Until it happens you probably don't know if you are disk, network, memory, or CPU bound. I see what you're saying. My point would be that the hardware cost is now so low that it doesn't really matter. You may not be able to predict whether 8 cores will be enough, but the Epyc 7452 at $2025 has 32. 256GB more server memory is below $1000. Enterprise SSDs are below $200/TB. 10Gbps network ports are below $100/port. If you don't know what you need you could spec the thing to be able to handle anything you might reasonably want to throw at it and still not be spending all that much money, even ignoring the possibility of upgrading the hardware as needed. > Once your stack is sufficiently mature and not changing much the workload gets a lot more predictable. The cloud is really good for starting out. The danger is it's also really good at locking you in, then you are stuck with it. Right. And the cloud advantage when you're starting out is directly proportional to the cost of the hardware you might need to buy in the alternative at a time when you're not sure you'll actually need it. But as the cost per unit performance of the hardware comes down, that advantage is evaporating.
  - eloff 7y ago
    I don't think the hardware is that trivial. I used to think that, but I've learned a lot more respect for the people who understand how to troubleshoot it, how to purchase compatible components, and spot troublesome products and brands. It's a whole career, it has its nuances. But you make some good points. In general I agree it's cheaper to vastly over provision than to use the cloud. And you can do things like build an insane IO system for your database, which you can only sort of do in the cloud. Of course this is an advantage for hosting internal company stuff, for web facing things you may need to place hardware in remote datacenters, and then you do need people on location on call who can service it. You have to generally have much larger scale for that to make sense. Even Netflix, because of the variability of their load still use a combination of cloud and their own hardware.

by zrm 7y ago

eloff 7y ago

Certainly if you have someone already on the payroll who can take responsibility for the hardware part time, that makes it a lot cheaper. That's a different skill set though, so it's not true for every company. With respect to changing workloads, I wasn't thinking so much about scale, which I think isn't that hard to plan for, but more about changing requirements. If you add, remove, or change a piece of your stack the cloud gives a lot of flexibility. Add memcached, no problem, spin up some high mem instances. Need more IO on the database server, switch to an instance with fast SSDs, or a bigger instance. I think those kinds of changes are common and hard to plan for. Until it happens you probably don't know if you are disk, network, memory, or CPU bound. Once your stack is sufficiently mature and not changing much the workload gets a lot more predictable. The cloud is really good for starting out. The danger is it's also really good at locking you in, then you are stuck with it.

zrm 7y ago
> Certainly if you have someone already on the payroll who can take responsibility for the hardware part time, that makes it a lot cheaper. That's a different skill set though, so it's not true for every company. True, though all the physical hardware stuff is pretty straight forward, to the point that anybody competent could figure it out in real time just by looking at the pictures in the manual. Configuring a hypervisor is the main thing you actually have to learn, and that's a fundamentally similar skillset to systems administration for the guests. Or for that matter the cloud vendor's provisioning interface. It's just different tooling. > If you add, remove, or change a piece of your stack the cloud gives a lot of flexibility. Add memcached, no problem, spin up some high mem instances. Need more IO on the database server, switch to an instance with fast SSDs, or a bigger instance. I think those kinds of changes are common and hard to plan for. Until it happens you probably don't know if you are disk, network, memory, or CPU bound. I see what you're saying. My point would be that the hardware cost is now so low that it doesn't really matter. You may not be able to predict whether 8 cores will be enough, but the Epyc 7452 at $2025 has 32. 256GB more server memory is below $1000. Enterprise SSDs are below $200/TB. 10Gbps network ports are below $100/port. If you don't know what you need you could spec the thing to be able to handle anything you might reasonably want to throw at it and still not be spending all that much money, even ignoring the possibility of upgrading the hardware as needed. > Once your stack is sufficiently mature and not changing much the workload gets a lot more predictable. The cloud is really good for starting out. The danger is it's also really good at locking you in, then you are stuck with it. Right. And the cloud advantage when you're starting out is directly proportional to the cost of the hardware you might need to buy in the alternative at a time when you're not sure you'll actually need it. But as the cost per unit performance of the hardware comes down, that advantage is evaporating.
- eloff 7y ago
  I don't think the hardware is that trivial. I used to think that, but I've learned a lot more respect for the people who understand how to troubleshoot it, how to purchase compatible components, and spot troublesome products and brands. It's a whole career, it has its nuances. But you make some good points. In general I agree it's cheaper to vastly over provision than to use the cloud. And you can do things like build an insane IO system for your database, which you can only sort of do in the cloud. Of course this is an advantage for hosting internal company stuff, for web facing things you may need to place hardware in remote datacenters, and then you do need people on location on call who can service it. You have to generally have much larger scale for that to make sense. Even Netflix, because of the variability of their load still use a combination of cloud and their own hardware.