Hi Lz, Thanks for sharing your ideas.
I have to admin that I prefer the limit factor to set the resource limit, not the percentage to set the resource request. Because usually the resource request is configured or calculated by Flink, and it indicates user required resources. It has the same semantic for all deployments(e.g. Yarn, K8s). Especially for the memory resource, giving a discount for the resource request may cause OOM. BTW, I am wondering why the users do not allocate fewer resources if they do not need. @Denis Cosmin NUTIU <dnu...@bitdefender.com> I really appreciate for that you want to work on this feature. Let's first to reach a consensus about the implementation. And then opening a PR is welcome. Best, Yang spoon_lz <spoon...@126.com> 于2021年9月1日周三 下午4:36写道： > > Hi,everyone > I have some other ideas for kubernetes resource Settings, as described by > WangYang in [flink-15648], which increase the CPU limit by a certain > percentage to provide more computational performance for jobs. Should we > consider the alternative of shrinking the request to start more jobs, which > would improve cluster resource utilization? For example, for some > low-traffic tasks, we can even set the CPU request to 0 in extreme cases. > Both limit enlargement and Request shrinkage may be required > > Best, > Lz > On 09/1/2021 16:06，Denis Cosmin NUTIU<dnu...@bitdefender.com> > <dnu...@bitdefender.com> wrote： > > Hi Yang, > > I have limited Flink internals knowledge, but I can try to implement > FLINK-15648 and open up a PR on GitHub or send the patch via email. How > does that sound? > I'll sign the ICLA and switch to my personal address. > > Sincerely, > Denis > > On Wed, 2021-09-01 at 13:48 +0800, Yang Wang wrote: > > Great. If no one wants to work on this ticket FLINK-15648, I will try to > get this done in the next major release cycle(1.15). > > Best, > Yang > > Denis Cosmin NUTIU <dnu...@bitdefender.com> 于2021年8月31日周二 下午4:59写道： > > Hi everyone, > > Thanks for getting back to me! > > > 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. > > I think that's correct. In the current behavior Flink will override the > resources settings "The memory and cpu resources(including requests and > limits) will be overwritten by Flink configuration options. All other > resources(e.g. ephemeral-storage) will be retained.'[1]. After reading the > comments from FLINK-15648[2], I'm not sure that it can be done in a clean > manner with pod templates. > > > 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. > > I agree with you! I have limited knowledge of Flink internals but the > kubernetes.jobmanager.limit-factor and kubernetes.taskmanager.limit-factor > seems to be the right way to do it. > > [1] Native Kubernetes | Apache Flink > <https://ci.apache.org/projects/flink/flink-docs-master/docs/deployment/resource-providers/native_kubernetes/#pod-template> > [2] [FLINK-15648] Support to configure limit for CPU and memory > requirement - ASF JIRA (apache.org) > <https://issues.apache.org/jira/browse/FLINK-15648> > > ------------------------------ > *From:* Yang Wang <danrtsey...@gmail.com> > *Sent:* Tuesday, August 31, 2021 6:04 AM > *To:* Alexis Sarda-Espinosa <alexis.sarda-espin...@microfocus.com> > *Cc:* Denis Cosmin NUTIU <dnu...@bitdefender.com>; matth...@ververica.com > <matth...@ververica.com>; user@flink.apache.org <user@flink.apache.org> > *Subject:* Re: Deploying Flink on Kubernetes with fractional CPU and > different limits and requests > > 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 <alexis.sarda-espin...@microfocus.com> > 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 <dnu...@bitdefender.com> > *Sent:* Donnerstag, 26. August 2021 15:55 > *To:* matth...@ververica.com > *Cc:* user@flink.apache.org; danrtsey...@gmail.com > *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: > > 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 < > dnu...@bitdefender.com> 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 > > > > >
