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How Seriously Does Your Cloud Hosting Provider Take Redundancy?

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Re: How Seriously Does Your Cloud Hosting Provider Take Redundancy?

#11

Post by michaelbuckbee »

NDizzle wrote: post #7
vilpponen wrote: post #5

Earlier quoted context omitted.

Thanks for the comment! A 100% SLA is actually a promise of future uptime. Nobody can of course guarantee their uptime, no matter what the SLA percentage. Thus, the company includes compensation in the agreement if the service level is not met. All this of course is decided based on historical data and what makes business sense for the company, ie. how much money are they willing to lose if their services go down.

Would you buy a car that guaranteed to never break down? Do you not understand how ridiculous a 100% uptime claim is? I don't even consider companies stupid enough to put out a blurb like that.

The key here is that that is for a SLA. So it's not that they'll never be down, but rather for every minute they are down they'll pay out money to you for the trouble.

To extend the car analogy, it's more like a lifetime warranty on a car: the car might break down all the time, but its still covered.

Re: How Seriously Does Your Cloud Hosting Provider Take Redundancy?

#12

Post by vilpponen »

NDizzle wrote: post #7
vilpponen wrote: post #5

Earlier quoted context omitted.

Thanks for the comment! A 100% SLA is actually a promise of future uptime. Nobody can of course guarantee their uptime, no matter what the SLA percentage. Thus, the company includes compensation in the agreement if the service level is not met. All this of course is decided based on historical data and what makes business sense for the company, ie. how much money are they willing to lose if their services go down.

Would you buy a car that guaranteed to never break down? Do you not understand how ridiculous a 100% uptime claim is? I don't even consider companies stupid enough to put out a blurb like that.

I would definitely buy a car if they advertised it to never break down - if the compensation on the promise would be good enough!

But seriously speaking, a 99.99% SLA is not more realistic or achievable in itself than any other SLA promise. It all depends on the provider (how they strive to reach that promise) and what they promise in return if the promise is broken.

Re: How Seriously Does Your Cloud Hosting Provider Take Redundancy?

#13

Post by lvh »

NDizzle wrote: post #7
vilpponen wrote: post #5

Earlier quoted context omitted.

Thanks for the comment! A 100% SLA is actually a promise of future uptime. Nobody can of course guarantee their uptime, no matter what the SLA percentage. Thus, the company includes compensation in the agreement if the service level is not met. All this of course is decided based on historical data and what makes business sense for the company, ie. how much money are they willing to lose if their services go down.

Would you buy a car that guaranteed to never break down? Do you not understand how ridiculous a 100% uptime claim is? I don't even consider companies stupid enough to put out a blurb like that.

Nobody claims they will give you 100% uptime. The service level agreement is at 100%, that just means that the service should be up 100%; when it isn't, you get compensated. They're saying that any percentage of downtime (modulo time limits) is bad, not that it won't happen.

Re: How Seriously Does Your Cloud Hosting Provider Take Redundancy?

#14

Post by tbrownaw »

NDizzle wrote: post #7
vilpponen wrote: post #5

Earlier quoted context omitted.

Thanks for the comment! A 100% SLA is actually a promise of future uptime. Nobody can of course guarantee their uptime, no matter what the SLA percentage. Thus, the company includes compensation in the agreement if the service level is not met. All this of course is decided based on historical data and what makes business sense for the company, ie. how much money are they willing to lose if their services go down.

Would you buy a car that guaranteed to never break down? Do you not understand how ridiculous a 100% uptime claim is? I don't even consider companies stupid enough to put out a blurb like that.

How is it ridiculous?

They're explicitly not saying that it will never go down. They're saying that if it ever does go down, they will pay their customers a penalty. Without having any "acceptable" amount of downtime that they don't have to pay a penalty for.

Really, too-many-9s SLAs are what's ridiculous. So you say you "guarantee" 99.99% uptime, but only interruptions of 30min or more actually count? 2 incidents of 29 minutes would put you over that .001% that you claim, without either counting.

Re: How Seriously Does Your Cloud Hosting Provider Take Redundancy?

#15

Post by switch007 »

There's nothing in that post about your data centers, just your "stack". Of what does your service stack comprise?

Why did you not opt for 2N?

Do you co-locate? What tier is the DC? If you colo, especially <= T3, your colo company has likely cut corners somewhere and that you don't know about some of the weaknesses in their infrastructure.

Re: How Seriously Does Your Cloud Hosting Provider Take Redundancy?

#16

Post by tbrownaw »

kordless wrote: post #2

SLAs are an artifact of the current business model where you have compute resources and I buy them from you. If we alter that model slightly where everyone buys compute from everyone else, the need for SLAs disappears completely. It's not surprising such a model would carry an immense amount of trust for availability, given it would be difficult for everyone to be 'down' all at once. The table listing the "confidence…

If we alter that model slightly where everyone buys compute from everyone else, the need for SLAs disappears completely

How long does failover take (and how reliable is it)? How much bandwidth is available for replication between your 3+ separate providers living in separate datacenters and cities, and how much does the latency for this slow your system down?

True fully-distributed systems are a Hard Problem. SLAs aren't an artifact of business models, so much as they (along with those business models) are a non-technical workaround for technical limitations.

Re: How Seriously Does Your Cloud Hosting Provider Take Redundancy?

#17

Post by vilpponen »

srcmap wrote: post #10

Just suffered my first app down for a few hours after 460+ days of uptime. The cause was SSD read errors, which trigger ext4 journaling errors and Linux turn fs into read only mode. From that point on the app failed because logging api failed. Just curious, does your SLA cover such outage case? My service provide said everything is normal from their POV which is kind of true.

If I've understood your situation correctly - then yes, this would be an issue that is covered by our SLA. Our customer data is actually hosted on two separate storage backends for issues like failing disk drives.

Our approach on this is that when we offer a service to you, you should not be worried about how the physical equipment functions - it should just work. Hence all issues on that front would be our responsibility. Glad to talk more on this if you're interested. My contact details can be found on our company website.

Re: How Seriously Does Your Cloud Hosting Provider Take Redundancy?

#18

Post by vilpponen »

dkokelley wrote: post #8

Strong SLAs are nice, but wouldn't the best measure be historical outages as a percentage of whole infrastructure uptime? For most application, receiving compensation for an SLA breach is negligible compared to the cost of an outage to the customer. One hour of downtime for an application paying $20,000/month for cloud services is worth $27.78. Even with a 100x multiplier the customer would be due a check/credit for…

"Given the choice, I'm sure most rational businesses would prefer the uptime over the credit."

How would you propose to compensate with uptime (if I've understood correctly)? Interested to learn your thoughts on this.

Re: How Seriously Does Your Cloud Hosting Provider Take Redundancy?

#19

Post by dkokelley »

vilpponen wrote: post #18
dkokelley wrote: post #8

Strong SLAs are nice, but wouldn't the best measure be historical outages as a percentage of whole infrastructure uptime? For most application, receiving compensation for an SLA breach is negligible compared to the cost of an outage to the customer. One hour of downtime for an application paying $20,000/month for cloud services is worth $27.78. Even with a 100x multiplier the customer would be due a check/credit for…

"Given the choice, I'm sure most rational businesses would prefer the uptime over the credit." How would you propose to compensate with uptime (if I've understood correctly)? Interested to learn your thoughts on this.

I'm not sure the best way to approach it. The issue is that there is (or can be) a huge imbalance between cost and impact for cloud service downtime. A business-critical application coming down for even an hour has the potential to cause significant heartache to the customer's business. The imbalance is so high that I'm not sure it's possible to justifiably compensate for your customer's business impact, based on what the market is for cloud services.

My thoughts on the matter are this:

* Nearly any compensation is "not enough" to a customer. They would have rather had the service not come down.

* It is nearly always better to use extravagant SLA breach compensation for higher redundancy. [1]

* Because 100% uptime is prohibitively expensive, transparency about historical uptime is vital for a prospect making a buying decision.

* The most fair way to compensate a customer for downtime is to take out an insurance policy against your service for the cost of downtime to your customer. (This is unique to each customer, and service should be priced accordingly.) [1]

1: Customers should be compensated for downtime, if at the very least because they aren't able to use the service they paid for. If additional money can't be used for additional redundancy/reliability, it can be used to insure against the cost of downtime.

Edit: After re-reading your question, I see that I misunderstood your question. I don't mean to say "Your customer was down for an hour, give them an hour (or more) for free." I actually meant "Your customer was down for an hour. That costs them $XX,XXX in headache. You can't expect to compensate them enough to cover that, so it would be better to avoid the downtime."

Re: How Seriously Does Your Cloud Hosting Provider Take Redundancy?

#20

Post by Khaine »

dkokelley wrote: post #19
vilpponen wrote: post #18

Earlier quoted context omitted.

"Given the choice, I'm sure most rational businesses would prefer the uptime over the credit." How would you propose to compensate with uptime (if I've understood correctly)? Interested to learn your thoughts on this.

I'm not sure the best way to approach it. The issue is that there is (or can be) a huge imbalance between cost and impact for cloud service downtime. A business-critical application coming down for even an hour has the potential to cause significant heartache to the customer's business. The imbalance is so high that I'm not sure it's possible to justifiably compensate for your customer's business impact, based on wha…

If an application is that business critical, then shouldn't the organisation be running it across multiple cloud providers, or ensuring it can run it internally?
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