Tip: Slow Wi-FI Speed due to the second Monitor

 Symptom:

  The wifi speed dropped to half after we connected a second monitor for extended display.

Tip:

  It is likely the 2 monitors have different refresh rate,60 Hertz vs 59 Hertz. Make them the same could help.

How to find which type of VMs pods are running via promQL

Requirement:

     Users need to know which type of VMs their pods are running. i.e. users wanna verify pods are running on GPU VMs

Solution:

In Prometheus, we have 2 metrics:  kube_pod_info{} and kube_node_lables{}

kube_node_labels often has a label to tell which type of VM it is. 

We can use "node" to join these 2 metrics to provide a report to users

sum( kube_pod_info{}) by(pod,node) *on(node) group_left(label_beta_kubernetes_io_instance_type) sum(kube_node_labels{}) by (node,label_beta_kubernetes_io_instance_type)

Please refer official promQL doc 

Tip: create grafana API for it:

curl -g -k -H "Authorization: Bearer ******" https://grafana.testtest.com/api/datasources/proxy/1/api/v1/query?query=sum\(kube_pod_info{}\)by\(pod,node\)*on\(node\)group_left\(label_beta_kubernetes_io_instance_type\)sum\(kube_node_labels{}\)by\(node,label_beta_kubernetes_io_instance_type\)

Als refer my blog how to convert promQL into grafana API call

How to convert PromQL into Grafana API call

Requirement:

     We use promQL to fetch some metadata of a Kubernetes cluster. i.e existing namespaces

sum(kube_pod_info) by (namespace)

We would like to convert it to a grafana API call, so other apps can consume this metadata

Solution:

• First, we need to generate an API token. Refer grafana doc 
• Second, below is a curl example to consume it:

curl -k -H "Authorization: Bearer e*****dfwefwef0=" https://grafana-test.testtest.com/api/datasources/proxy/1/api/v1/query?query=sum\(kube_pod_info\)by\(namespace\)