I have written an app in Rust, which can be deployed on my Kubernetes cluster as a daemonset and it will collect the resource usage data of all the nodes, and export those details to my server.
Now, node represents a machine (a real entity).
One can easily extract resource usage of a node with OS monitoring libraries (Ex. https://crates.io/crates/sysinfo). On the other hand pods are abstractions.
I also want to collect Kubernetes pod details.
currently, I am extracting pod usage using kube-rs SDK.
But, as my code is running inside the cluster, can I do something else that can give me even better performance for collecting pod / container metrics ?
In short, is there a better way of getting pod metrics from inside the cluster ? (a way which is Rust friendly !)
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We are planning on delivering small k8s clusters to clients with our application on top.
Currently we are struggling on see what resources we actually need. At average we are running 20-30 pods in the system.
While getting resources requests and limits per deployment is not hard to see.
It is hared to get full view of all requests or all limits resources for all pods that are running in the cluster. At least in an automated way.
Is there prebuild dashboard in Grafana or some kind of kubectl command that would collect all of the requests and limits for all pods running in the k8s cluster?
The result should be a "nice" report for all resource requirements.
Since we are delivering a "static" cluster to clients there is no hpa roles in our clusters.
So far we have done manual check per each pod and write it in Excel table which is not time efficient and repeatable.
Hi skolko you can use prometheus for monitoring your kubernetes cluster there are various options available like monitoring individual deployments, monitoring entire cluster and monitoring each pod individually. Follow this document for setting up the prometheus monitoring for kubernetes and this document for getting an overview on metrics available for monitoring.
We have a bunch of pods running in dev environment. The pods are auto-provisioned by an application on every business action. The problem is that across various namespaces they are accumulating and eating available resources in EKS.
Is there a way without jenkins/k8s jobs to simply put some parameter on the pod manifest to tell it to self destruct say in 24 hours?
Add to your pod.spec:
activeDeadlineSeconds: 86400
After deadline your Pod will be stopped for good with the status DeadlineExceeded
If I understood your situation properly, you would like to scale your cluster down in order to save resources.
Kubernetes is featured with the ability to autoscale your application in a cluster. Literally, it means that Kubernetes can start additional pods when the load is increasing and terminate excessive pods when the load is decreasing.
It is possible to downscale the application to zero pods, but, in this case, you will have a delay serving the first request while the pod is starting.
This functionality relies on performance metrics. From the practical side, it means that autoscaling doesn't happen instantly, because it takes some time to performance metrics reach the configured threshold.
The mentioned Kubernetes feature called HPA(horizontal pod autoscale) is described in this document.
In case you are running your cluster on GCP or GKE, you are able to go further and automatically start additional nodes for your cluster when you need more computing capacity and shut down nodes when they are not running application pods anymore.
More information about this functionality can be found following the link.
Last, but not least, you can use tool like Ansible to manage all your kubernetes assets (it can create/manage deployments via playbooks).
If you decide to give it a try, you might find this information useful:
Creating a Container cluster in GKE
70% cheaper Kubernetes cluster on AWS
How to build a Kubernetes Horizontal Pod Autoscaler using custom metrics
we are using k8s cluster for one of our application, cluster is owned by other team and we dont have full control over there… We are trying to find out metrics around resource utilization (CPU and memory), detail about running containers/pods/nodes etc. Need to find out how many parallel containers are running. Problem is they have exposed monitoring of cluster via Prometheus but with Prometheus we are not getting live data, it does not have info about running containers.
My query is , what is that API which is by default available in k8s cluster and can give all what we need. We dont want to read data form another client like Prometheus or anything else, we want to read metrics directly from cluster so that data is not stale. Any suggestions?
As you mentioned you will need metrics-server (or heapster) to get those information.
You can confirm if your metrics server is running kubectl top nodes/pods or just by checking if there is a heapster or metrics-server pod present in kube-system namespace.
Also the provided command would be able to show you the information you are looking for. I wont go into details as here you can find a lot of clues and ways of looking at cluster resource usage. You should probably take a look at cadvisor too which should be already present in the cluster. It exposes a web UI which exports live information about all the containers on the machine.
Other than that there are probably commercial ways of acheiving what you are looking for, for example SignalFx and other similar projects - but this will probably require the cluster administrator involvement.
I have played around a little bit with docker and kubernetes. Need some advice here on - Is it a good idea to have one POD on a VM with all these deployed in multiple (hybrid) containers?
This is our POC plan:
Customers to access (nginx reverse proxy) with a public API endpoint. eg., abc.xyz.com or def.xyz.com
List of containers that we need
Identity server Connected to SQL server
Our API server with Hangfire. Connected to SQL server
The API server that connects to Redis Server
The Redis in turn has 3 agents with Hangfire load-balanced (future scalable)
Setup 1 or 2 VMs?
Combination of Windows and Linux Containers, is that advisable?
How many Pods per VM? How many containers per Pod?
Should we attach volumes for DB?
Thank you for your help
Cluster size can be different depending on the Kubernetes platform you want to use. For managed solutions like GKE/EKS/AKS you don't need to create a master node but you have less control over our cluster and you can't use latest Kubernetes version.
It is safer to have at least 2 worker nodes. (More is better). In case of node failure, pods will be rescheduled on another healthy node.
I'd say linux containers are more lightweight and have less overhead, but it's up to you to decide what to use.
Number of pods per VM is defined during scheduling process by the kube-scheduler and depends on the pods' requested resources and amount of resources available on cluster nodes.
All data inside running containers in a Pod are lost after pod restart/deletion. You can import/restore DB content during pod startup using Init Containers(or DB replication) or configure volumes to save data between pod restarts.
You can easily decide which container you need to put in the same Pod if you look at your application set from the perspective of scaling, updating and availability.
If you can benefit from scaling, updating application parts independently and having several replicas of some crucial parts of your application, it's better to put them in the separate Deployments. If it's required for the application parts to run always on the same node and if it's fine to restart them all at once, you can put them in one Pod.
I have an issue that, at face value, appears to indicate that I have two deployments running in parallel within my kube cluster, but 'kubectl get pods' only shows one deployment.
My deployment is composed of a pod with two containers. One of the containers runs a golang application that creates an http API endpoint, and the other runs Telegraf to read metrics from the API endpoint and push them to InfluxDB. When writing the data to Influx I tag the data with the source host as the name of the pod. I use Grafana to plot the metrics and I can clearly see incoming streaming data coming from two hosts (e.g. I can set a "WHERE host=" query clause as either "application-pod-name-231620957-7n32f" and "application-pod-name-1931165991-x154c").
Based on the above, I'm fairly certain that two deployments of the pod are running, each with the two containers (one providing application metrics and the other with telegraf sending metrics to InfluxDB).
However, kube seems to think that one of the deployments doesn't exist. As mentioned, "kubectl get pods" doesn't display the 2nd pod name in any way shape or form. Only one of them.
Has anyone seen this? Any ideas on further troubleshooting? I've attempted to use the pod name (that I have within telegraf) to query more information using kubectl but always get the response that the pod doesn't exist... but it must exist! It's sending live data!
We had been experiencing issues with a node within the cluster. Specifically, the node was experiencing GC failures and communications into the cluster from that node was broken. Due to these failures, someone on our team performed a 'kubectl delete' on the node from within the cluster. By doing so the node continued running, but also the kubelet running on the node remained in a broken state, and so the node couldn't re-auto-register itself into the cluster. This node happened to be running the 2nd pod, and the pods running on the node continued running without issue. In our case, the node was running on AWS, in which case the way to avoid this situation is to reboot the node either from the AWS console or AWS API.