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Do I Need Kubernetes?

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Re: Do I Need Kubernetes?

#71

Post by Yizahi »

spost wrote: post #23

I work for a startup whose product is small (half a dozen servers, if relatively beefy ones) clusters that will be run on-prem by customers, at least sometimes in a low-to-no-touch capacity. Most of our application components are micro-ish services that are run on all hosts in the cluster for either extra capacity or fault tolerance. We currently run everything on mesos/marathon, but are looking to switch away from i…

One reason for example can be providing better reliability to the customers who were using certain application on premises and need/want to continue doing so. I've observed how our solution switched from monolithic blob of cpp code which crashed everything upon major failures; to the several modules - now your monitoring may crash and restart but hopefully service won't be interrupted, but when performance part crashed - all service stopped, and maintenance time was long; to the k8s - when all parts are split into separate containers and performance part is split into smaller chunks completely redundant, so when one crashes it is a) restarted without affecting 99% of other users, b) it is restarted much quicker, ten times quicker, meaning less down time to 1% affected users.

But k8s introduced non trivial amount of complexity and its own bugs and maintenance cost, meaning new separate engineers to maintain and develop just k8s tooling. And we had to rewrite a lot of legacy code. But the trade off is much better for a big project. Cutting downtimes by an order of magnitude and being able to boast it to the board - apparently priceless :) .

Re: Do I Need Kubernetes?

#73

Post by throwaway894345 »

overgard wrote: post #65

I think one of the underrated parts of using something like Kubernetes early (or even w/ simpler orchestrators like swarm or rancher), is that it encourages (and sometimes enforces) architecture best practices from the start. IE, you won't be storing state locally, you'll be able to handle servers being randomly killed, you'll already have horizontal scaling, etc. In my experience the hard part of migrating to contai…

I’m not avidly opposed to k8s by any means, but you can get these same properties from any of a variety of easier-to-use schedulers such as Fargate, Heroku, or even EC2 autoscaling groups. Of course, there are probably Kubernetes distributions that lower the threshold of using Kubernetes (and if there aren’t, there really should be) by providing solutions for logging, monitoring, certificate management, Functions (a la AWS Lambda), load balancing / ingress, state management (databases as a service), etc preconfigured out of the box (similar to what you get with AWS or Heroku).

Re: Do I Need Kubernetes?

#74

Post by moomin »

overgard wrote: post #65

I think one of the underrated parts of using something like Kubernetes early (or even w/ simpler orchestrators like swarm or rancher), is that it encourages (and sometimes enforces) architecture best practices from the start. IE, you won't be storing state locally, you'll be able to handle servers being randomly killed, you'll already have horizontal scaling, etc. In my experience the hard part of migrating to contai…

Seriously though, the world needs a solution for Kubernetes like problems that involve UDP and multicast.

Re: Do I Need Kubernetes?

#75

Post by gatvol »

gatvol wrote: post #72

Probably not. Why not utilise ECS/ Fargate and attach managed services, rather then tending a whole now flock of things?

Using Docker-compose for local dev works very well for our teams, and we avoid the overhead of running and learning K8s operationally. That said this approach may change for us if we were large Health or insurance company scale, but we're not.

Re: Do I Need Kubernetes?

#76

Post by threeseed »

throwaway894345 wrote: post #73
overgard wrote: post #65

I think one of the underrated parts of using something like Kubernetes early (or even w/ simpler orchestrators like swarm or rancher), is that it encourages (and sometimes enforces) architecture best practices from the start. IE, you won't be storing state locally, you'll be able to handle servers being randomly killed, you'll already have horizontal scaling, etc. In my experience the hard part of migrating to contai…

I’m not avidly opposed to k8s by any means, but you can get these same properties from any of a variety of easier-to-use schedulers such as Fargate, Heroku, or even EC2 autoscaling groups. Of course, there are probably Kubernetes distributions that lower the threshold of using Kubernetes (and if there aren’t, there really should be) by providing solutions for logging, monitoring, certificate management, Functions (a…

The problem with your approach is that you're firmly locked in to the vendor.

And in the case of Fargate, Heroku etc you're paying significantly more than if you had made use of Spot instances or shopped around for a cheaper vendor.

Re: Do I Need Kubernetes?

#77

Post by threeseed »

k__ wrote: post #68

This sounds like people try to compare K8s with what was before and sure, that all holds true. You get all of this with serverless (be it with managed services or FaaS), with reduced (albeit not zero) complexity compared to K8s.

And with serverless you get significant lock-in, are overpaying for resources, have less ability to debug when things go wrong, have basically zero flexibility and it's very difficult to have a local setup mirror your production one.

It's fine for certain use cases but you get the benefits of both worlds by just using a managed K8s service like AWS EKS.

Re: Do I Need Kubernetes?

#79

Post by otterley »

jrott wrote: post #36
peterwwillis wrote: post #13

Here's a quick reference: 1) Are you on AWS? Then you don't need Kubernetes. Use Fargate. 2) Are you on Google Cloud? Then you don't need Kubernetes. Use Cloud Run. 3) Are you on Azure? Then you don't need Kubernetes. Use Azure Container Instances. 4) Are you on a PaaS like Heroku? Then you don't need Kubernetes. 5) Are you on a random VPC provider / bare metal machines? You could probably still do without Kubernetes…

I get that feeling however I know for fargate there are some vertical scaling limitations that don't exist with kubernetes. Also at this point there is a ton of stuff out there that assumes you are deploying to kubernetes and makes that the path of least resistance.

> I know for fargate there are some vertical scaling limitations that don't exist with kubernetes

To overcome those limitations, you can use EC2 Container Instances with ECS. And instance auto scaling can now be automated for you via ECS Capacity Providers.

Re: Do I Need Kubernetes?

#80

Post by ezekiel68 »

Axsuul wrote: post #67

I need Kubernetes since we're outgrowing Docker Swarm. Docker Swarm has a lot of issues we deal with on a constant basis so it's becoming quite painful. Can anyone suggest a good migration guide from Docker Swarm -> Kubernetes?

My gentle suggestion is to avoid phrases like "a lot of issues" and instead to list some of the top ones. This could give some people a chance to share how they have overcome some of those specific challenges.

At a recent employer, we moved cold turkey from Swarm to Kubernetes (K8s in the rest of this reply). But we did this one microservice at a time. We didn't want our resulting K8s solution to be compromised by a misguided attempt to foist Swarm concept into the K8s way. Probably the biggest decision to make is whether to manage the cluster from scratch (not recommended), by using kops to deploy on a cloud platform, or use a cloud-native solution like EKS on AWS. After that -- here's a good guide to help with the differences in configuring the services[1]

[1] https://kubernetes.io/docs/tasks/configure-pod-container/tra...

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