I’d say being able to set I/O limits can be much more useful than CPU limits regardless of platform. Less chance of bringing an entire host to a halt.
For the Love of God, Stop Using CPU Limits on Kubernetes
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Re: For the Love of God, Stop Using CPU Limits on Kubernetes
#12Almost 2-yo post and still as wrong as it was when it was posted.
What’s wrong about it? I haven’t managed k8s much and don’t have enough experience to evaluate their claim.
K8s works best (economically) when it can bin pack things. The only way it can bin pack things safely is by having user provided limits--its not smart enough to right size your app (out of the box at least). Not setting them means you're going to end up paying more or have resource contention/outages.
It's better to set the limits higher than you need than to not set them at all. Ideally this is easily done since you're profiling/load testing your app and you understand the appropriate sizing for it, right?
Re: For the Love of God, Stop Using CPU Limits on Kubernetes
#13Earlier quoted context omitted.
What’s wrong about it? I haven’t managed k8s much and don’t have enough experience to evaluate their claim.
K8s works best (economically) when it can bin pack things. The only way it can bin pack things safely is by having user provided limits--its not smart enough to right size your app (out of the box at least). Not setting them means you're going to end up paying more or have resource contention/outages. It's better to set the limits higher than you need than to not set them at all. Ideally this is easily done since you…
Unless your app can use all the cpu you assign it
Re: For the Love of God, Stop Using CPU Limits on Kubernetes
#14Earlier quoted context omitted.
What’s wrong about it? I haven’t managed k8s much and don’t have enough experience to evaluate their claim.
Users come to expect the performance that was never promised or even properly requested. Once you efficiently load the system they complain because you overdelivered and they got used to it.
We've been fixing that over time and now no one expects a computer to be as fast as it accidentally was in 2010.
Re: For the Love of God, Stop Using CPU Limits on Kubernetes
#15Earlier quoted context omitted.
What’s wrong about it? I haven’t managed k8s much and don’t have enough experience to evaluate their claim.
K8s works best (economically) when it can bin pack things. The only way it can bin pack things safely is by having user provided limits--its not smart enough to right size your app (out of the box at least). Not setting them means you're going to end up paying more or have resource contention/outages. It's better to set the limits higher than you need than to not set them at all. Ideally this is easily done since you…
Ha! Always end with a joke, I love it.
Re: For the Love of God, Stop Using CPU Limits on Kubernetes
#16Earlier quoted context omitted.
What’s wrong about it? I haven’t managed k8s much and don’t have enough experience to evaluate their claim.
Users come to expect the performance that was never promised or even properly requested. Once you efficiently load the system they complain because you overdelivered and they got used to it.
I'm sorry, in what way are modern servers not fast enough to serve a few hundred CRUD requests per second?
Re: For the Love of God, Stop Using CPU Limits on Kubernetes
#17Earlier quoted context omitted.
Users come to expect the performance that was never promised or even properly requested. Once you efficiently load the system they complain because you overdelivered and they got used to it.
We've been fixing that over time and now no one expects a computer to be as fast as it accidentally was in 2010.
Why, by 2030, computers ought to be even slower!
Re: For the Love of God, Stop Using CPU Limits on Kubernetes
#18Can't your operating system manage your CPU resources for you already? Why does Kubernetes need to be involved in process scheduling?
Re: For the Love of God, Stop Using CPU Limits on Kubernetes
#19Can't your operating system manage your CPU resources for you already? Why does Kubernetes need to be involved in process scheduling?
Kubernetes is giving my operating system the cpu to manage.
Re: For the Love of God, Stop Using CPU Limits on Kubernetes
#20I used to be on the same page as the author. But then I saw tons of application teams not setting CPU limits, and coming to rely on the bursting (in other words, their requests were too low). Thus when the system came under load their application started slowing in unexpected ways. We've had success with CPU limits, and horizontal scaling.
He does address that at the end of the article with the dashboard that looks at historical usage to inform your cpu requests.