loudwhisper

No, it's not true. A single system has less failure scenarios, because it doesn't depend on external controllers or anything that makes the system distributed and that can fail causing a failure to your system (which may or may not be tolerated).

This is especially true from a security standpoint: complexity adds attack surface.

Simple example: a kubernetes cluster has more failure scenarios than a single node. With the node you have hardware failure, misconfiguration of the node, network failure. With a kubernetes cluster you have all that for each node (each with marginally less impact, potentially, because it depends for example on stateful storage, that if you mitigate you are introducing other failure scenarios as well), plus the fact that if the control plane goes in flames your node is useless, if the etcd data corrupts your node is useless, anything that happens with resources (a bug, a misuse of the API, etc.) can break your product. You have more failure scenarios because your product to run is dependent on more components to work at the same time. This is what it means that complexity brings fragility. Looking from the security side: an instance can be accessed only from SSH, if you are worried about compromise you have essentially one service to secure. Once you run on kubernetes you have the CI/CD system, the kubernetes API, the kubernetes supply-chain, etcd, and if you are in cloud you have plenty of cloud permissions that can indirectly grant you access to the control plane and to a console. Now you need to secure 5-6-7 entrypoints to a node.

Mind you, I am not advocating against the use of complex systems, sometimes they are necessary, but if the complexity is not fully managed and addressed, you have a more fragile system. Essentially complexity is a necessary evil to respond to some other necessities.

This is the reason why nobody would recommend to someone who needs to run a single static website to run it on Kubernetes, for example.

You say "a well designed system", but designing well is harder the more complexity exists, obviously. Redundancy doesn't always work, because redundancy needs coordination, needs processes that also depend on external components.

In any case, I agree that you can build a robust system within Cloud! The argument I am trying to make is that:

• you need to be aware that you are introducing complexity that needs attention and careful design if you don't want it to result in more fragility and exposure
• you need to spend way more money
• you need to balance the cost with the actual benefits you are gaining

And mind you, everything you can do in Cloud you can also do on your own, if you invest on it.

If your compute needs expand that much everyday, and possibly shrink in others, than your use-case is one that can benefit from Cloud (I covered this in the post).

That said, if provisioning means recycle, then it's obviously not a problem.

This is a very rare requirement. Most companies' load is fairly stable and relatively predictable, which means that with a proper capacity planning, increasing compute resources is something that happens rarely too. So rarely that even a lead time for hardware is acceptable.

So if I may ask (and you can tell), what is the purpose of provisioning that many systems each day? Are they continuously expanding?

With a lot of stuff on top!

Not OP, but they are comparable efforts, especially since it's a relatively infrequent activity. You can rent dedicated boxes with off-the-sheld hardware almost instantly, if you don't want to deal with the hardware procurement, and often you can do that via APIs as well. And of course both options are much, much, much cheaper than the Cloud solution.

For sure speed in general is something Cloud provide. I would say it's a very bad metric though in this context.

Of course the problem is solved, but that doesn't mean that the solution is easy. Also, distributed protocols still need to work on top of a complicated network and with real-life constraints in terms of performances (to list a few). A bug, misconfiguration, oversight and you have a problem.

Just to make an example, I remember a Kafka cluster with 5 replicas completely shitting its pants for 6h to rebalance data during a planned maintenance where one node was brought offline. It caused one of the longest outages to date with the websites which relied on it offline. Was it our fault? Was it a misconfiguration? A bug? It doesn't matter, it's a complex system which was implemented and probably something was missed.

Technology is implemented by people, complexity increased the chances of mistakes, not sure this can be argued.

Making it harder to identify SPOF means you might miss your SPOF, and that means having liabilities, and having anyway scenarios where your system can crash, in addition for paying quite a lot to build a resilience that you don't achieve.

A single instance with 2 failure scenarios (disk failure and network failure) - to make an example - is not more fragile than a distributed system with 20 failure scenarios. Failure scenarios and SPOF can have compensating controls and be mitigated successfully. A complex system where these can't be fully identified can't have compensating control and residual risk might be much harder. So yes, a single disk can fail more likely than 3 disks at once, but this doesn't give the whole picture.

Thanks, that is a very good observation! I will try to sneak an edit later today where I can add some appendix about acronyms and abbreviations.

Edit:

While it might not look great, I have added at the bottom an Appendix with all (hopefully, I might have missed some) acronyms and abbreviations. Thanks for the suggestion!

I wish it worked like that, but I donct think it does. Connecting clouds means introducing many complex problems. Data synchronization and avoiding split-brain scenarios, a network setup way more complex, stateful storage that needs to take into account all the quirks and peculiarities of all services across all clouds, service accounts and permissions that need to be granted and segregated for all of them, and way more. You may gain resilience in some areas, but you introduce a lot more things that can fail, be misconfigured or compromised.

Plus, a complex setup makes it harder by definition to identify SPOFs, especially considering it's very likely nobody in the workforce is going to be an expert in all the clouds in use.

To keep using your simile of the disks, a single disk with a backup might be a better solution for many people, considering you otherwise might need a RAID controller that can fail and all the knowledge to handle and manage a RAID array properly, in addition to paying 4 or 5 times the storage. Obviously this is just to make a point, I don't actually think that RAID 5 vs JBOD introduces comparable complexity compared to what multi-cloud architecture does to single-cloud.

Complexity brings fragility. It's not about doing the job right, is that "right" means having to deal with a level of complexity, a so high number of moving parts and configuration options, that the bar is set very high.

Also, I would argue that a large number of organizations don't actually need the resilience that they pay a very high price for.

Yeah in general you can't mess the building blocks from the PoV of availability or internal design. That is true, since you are outsourcing it. You can still mess them up from other points of view (think about how many companies got breached due to misconfigured S3 buckets).

Thanks! I went and tried on my phone and indeed setting Firefox to light mode indeed causes that horrendous and unreadable result. I will need to figure out way, eventually, and provide an alternative light scheme.

cognito auth

But then at that point you are already vendor-locked, right? At that point, running on bare ec2 instances and taking more control in your hands (vs using even more AWS-specific services) is going to help very little, when your whole user management is now tied to a specific provider.

How do you get this? Anything that tries to force a light mode?

This is how the site is supposed to look like (there is no light/dark theme selection):