Hi all,
I think it is a good improvement to support different resource requests and
limits. And it is very useful
especially for the CPU resource since it heavily depends on the upstream
workloads.
Actually, we(alibaba) have introduced some internal config options to
support this feature. WDYT?
// The prefix of Kubernetes resource limit factor. It should not be
less than 1. The resource
// could be cpu, memory, ephemeral-storage and all other types
supported by Kubernetes.
public static final String KUBERNETES_JOBMANAGER_RESOURCE_LIMIT_FACTOR_PREFIX =
"kubernetes.jobmanager.limit-factor.";
public static final String KUBERNETES_TASKMANAGER_RESOURCE_LIMIT_FACTOR_PREFIX =
"kubernetes.taskmanager.limit-factor.";
BTW, we already have an old ticket for this feature[1].
[1]. https://issues.apache.org/jira/browse/FLINK-15648
Best,
Yang
Alexis Sarda-Espinosa <[email protected]> 于2021年8月26日周四
下午10:04写道：
> I think it would be nice if the task manager pods get their values from
> the configuration file only if the pod templates don’t specify any
> resources. That was the goal of supporting pod templates, right? Allowing
> more custom scenarios without letting the configuration options get bloated.
>
>
>
> Regards,
>
> Alexis.
>
>
>
> *From:* Denis Cosmin NUTIU <[email protected]>
> *Sent:* Donnerstag, 26. August 2021 15:55
> *To:* [email protected]
> *Cc:* [email protected]; [email protected]
> *Subject:* Re: Deploying Flink on Kubernetes with fractional CPU and
> different limits and requests
>
>
>
> Hi Matthias,
>
>
>
> Thanks for getting back to me and for your time!
>
>
>
> We have some Flink jobs deployed on Kubernetes and running kubectl top pod
> gives the following result:
>
>
>
>
> NAME CPU(cores)
> MEMORY(bytes)
> aa-78c8cb77d4-zlmpg 8m 1410Mi
> aa-taskmanager-2-2 32m 1066Mi
> bb-5f7b65f95c-jwb7t 7m 1445Mi
> bb-taskmanager-2-2 32m 1016Mi
> cc-54d967b55d-b567x 11m 514Mi
> cc-taskmanager-4-1 11m 496Mi
> dd-6fbc6b8666-krhlx 10m 535Mi
> dd-taskmanager-2-2 12m 522Mi
> xx-6845cf7986-p45lq 53m 526Mi
> xx-taskmanager-5-2 11m 507Mi
>
>
>
> During low workloads the jobs consume just about 100m CPU and during high
> workloads the CPU consumption increases to 500m-1000m. Having the ability
> to specify requests and limit separately would give us more deployment
> flexibility.
>
>
>
> Sincerely,
>
> Denis
>
>
>
> On Thu, 2021-08-26 at 14:22 +0200, Matthias Pohl wrote:
>
> *CAUTION:* This email originated from outside of our organization. Do not
> click links or open attachments unless you recognize the sender and know
> the content is safe.
>
> Hi Denis,
>
> I did a bit of digging: It looks like there is no way to specify them
> independently. You can find documentation about pod templates for
> TaskManager and JobManager [1]. But even there it states that for cpu and
> memory, the resource specs are overwritten by the Flink configuration. The
> code also reveals that limit and requests are set using the same value [2].
>
>
>
> I'm going to pull Yang Wang into this thread. I'm wondering whether there
> is a reason for that or whether it makes sense to create a Jira issue
> introducing more specific configuration parameters for limit and requests.
>
>
>
> Best,
> Matthias
>
>
>
> [1]
> https://ci.apache.org/projects/flink/flink-docs-master/docs/deployment/resource-providers/native_kubernetes/#fields-overwritten-by-flink
>
> [2]
> https://github.com/apache/flink/blob/f64261c91b195ecdcd99975b51de540db89a3f48/flink-kubernetes/src/main/java/org/apache/flink/kubernetes/utils/KubernetesUtils.java#L324-L332
>
>
>
> On Thu, Aug 26, 2021 at 11:17 AM Denis Cosmin NUTIU <
> [email protected]> wrote:
>
> Hello,
>
> I've developed a Flink job and I'm trying to deploy it on a Kubernetes
> cluster using Flink Native.
>
> Setting kubernetes.taskmanager.cpu=0.5 and
> kubernetes.jobmanager.cpu=0.5 sets the requests and limits to 500m,
> which is correct, but I'd like to set the requests and limits to
> different values, something like:
>
> resources:
> requests:
> memory: "1048Mi"
> cpu: "100m"
> limits:
> memory: "2096Mi"
> cpu: "1000m"
>
> I've tried using pod templates from Flink 1.13 and manually patching
> the Kubernetes deployment file, the jobmanager gets spawned with the
> correct reousrce requests and limits but the taskmanagers get spawned
> with the defaults:
>
> Limits:
> cpu: 1
> memory: 1728Mi
> Requests:
> cpu: 1
> memory: 1728Mi
>
> Is there any way I could set the requests/limits for the CPU/Memory to
> different values when deploying Flink in Kubernetes? If not, would it
> make sense to request this as a feature?
>
> Thanks in advance!
>
> Denis
>
>
