Skip to main content

Monitoring & Logging in Kubernetes


Monitoring cluster components of Kubernetes (K8s)

There are various type of monitoring we can perform at the cluster, node level and pod level. At cluster level we can monitor like number nodes running, how many are healthy, performance status, network usage etc.


 At the POD level we can monitor disk and cpu, memory utilisation, Performance metrics of each POD about its resources.

To utilise the experience of monitoring on kubernetes cluster we can use “Metrics server” 

We can have 1 metrics server per cluster. It's retrieves the information about Nodes , PODS aggregate them and store them into memory. 

Matrics server is IN-MEMORY solution where the data or information which it fatch from nodes and pod will be in memory and does not store it in disk. 

As Metrics server is "IN-MEMORY" where it's not possible to retrieve the historical data about the kubernetes resources. To get the historical data its require to use advance tool or proprietors monitoring tool supporting kubernetes

So how does the Metrics Server get data?? 

As you know each nodes having an agent called KUBLET which is responsible to get information from API server for running and assigning pods.


KUBELET is also running sub component which called cAdvisor or container advisor.

cAdvisor is responsible for exposing performance metrics from POD and exposing it to API server then it get the data available to Metrics server.

For enabling feature use below:

For minikube : Use below code to enable metrics-server.
>minikube addons enable metrics-server


For all other environment Clone the metrics server from GitHub repository.
>git clone https://github.comkubernetes-incubator/metrics-server.git

  • Kubectl create -f deploy/1.8+/ ( run this command after cloning. It may take time to install and configure MATRICS server so be patience.

  • Kubectl top nodes ( to view the metrics about nodes)

  • Kubectl top pod ( to view the metrics about PODS)

Application logging

For watching logs of containers into the POD we can use command “kubectl log -f (pod name) . This will give you the list of events  which fetch all the containers events.

What if we want to fetch event of specific containers in a pod. For gaining this objective we need to add one parameter into the pod definition file under spec section.

  • Name : image-processor
    image: some-image-processor
 Now to get the logs for the container using below command



Kubectl log -f (pod name) (container name)


Happy learning..... :)
Labels:

Comments

Post a Comment

Popular posts from this blog

VCF 9 Networking : Centralized vs Distributed Connectivity

  VCF 9 Networking : Centralized vs Distributed Connectivity With the release of VMware Cloud Foundation 9 (VCF 9.0) , VMware has redefined the private cloud networking model by introducing both centralized and distributed connectivity. This dual approach provides flexibility for organizations to choose between traditional edge-based routing and modern, host-level distributed networking. Why New Networking in VCF 9? Prior to VCF 9, NSX networking was largely edge-centric—requiring dedicated Edge clusters to handle north-south traffic. This created scaling and operational overheads. VCF 9 introduces a cloud-like networking abstraction with: Native VPCs (Virtual Private Clouds) for tenant isolation. Transit Gateways (TGW) to interconnect VPCs and external networks. Simplified bootstrapping – NSX VIBs are embedded in ESXi for easier enablement. Improved lifecycle and visibility via integrated VCF Operations. These enhancements align with VMware’s goal of offer...
Post a Comment
Read more

Changing the FQDN of the vCenter appliance (VCSA)

This article states how to change the system name or the FQDN of the vCenter appliance 6.x You may not find any way to change the FQDN from the vCenter GUI either from VAMI page of from webclient as the option to change the hostname always be greyed out. Now the option left is from the command line of VCSA appliance. Below steps will make it possible to change the FQDN of the VCSA from the command line. Access the VCSA from console or from Putty session. Login with root permission Use above command in the command prompt of VCSA : /opt/vmware/share/vami/vami_config_net Opt for option 3 (Hostname) Change the hostname to new name Reboot the VCSA appliance.   After reboot you will be successfully manage to change the FQDN of the VCSA . Note: Above step is unsupported by VMware and may impact your SSL certificate and face problem while logging to vSphere Web Client. If you are using self-signed certificate, you can regenerate the certificate with...
2 comments
Read more

High-Speed Networking for VMs: VMXNET3 Now Supports Up to 65 Gbps

The VMXNET3 adapter is VMware's high-performance virtual network adapter, designed for optimized performance in vSphere environments. It is the default and recommended adapter for most modern workloads on ESXi , delivering high throughput, low latency, and support for advanced networking features. With the release of vSphere ESXi 8.0 Update 2 , VMXNET3 introduces new capabilities that significantly enhance virtual network performance. What’s New in ESXi 8.0 Update 2 for VMXNET3? Traditionally, VMXNET3 reports a default link speed of 10 Gbps to the guest operating system. However, the actual achievable throughput often exceeds this value—thanks to technologies such as multi-queue support , Receive Side Scaling (RSS) , and Large Packet Offload . Starting with ESXi 8.0 Update 2 , this limitation can now be overridden , and VMXNET3 can be configured to support custom link speeds of up to 65 Gbps . This enhancement enables improved flexibility and throughput for high-performance w...
Post a Comment
Read more