oc_adm_top.md

Using oc adm top to Present Platform Usage Statistics

The oc adm top command analyzes resources managed by the platform and presents current usage statistics. The information provided by this command gives operations valuable insight into cluster capacity.

Step 1

Ensure that you're logged into the cluster with the cluster-admin cluster role.

# oc login -u system:admin

Step 2

Now lets see what oc adm top has to offer by listing it's --help output

# oc adm top --help

Show usage statistics of resources on the server 

This command analyzes resources managed by the platform and presents current usage statistics.

Usage:
  oc adm top [options]

Available Commands:
  images       Show usage statistics for Images
  imagestreams Show usage statistics for ImageStreams
  node         Display Resource (CPU/Memory/Storage) usage of nodes
  pod          Display Resource (CPU/Memory/Storage) usage of pods

Use "oc adm <command> --help" for more information about a given command.
Use "oc adm options" for a list of global command-line options (applies to all commands).

Step 3

Now lets see how our all our nodes are doing.

# oc adm top nodes

NAME                  CPU(cores)   CPU%      MEMORY(bytes)   MEMORY%   

master.example.com    600m         30%       11560Mi         73%       
node1.example.com     98m          2%        10306Mi         65%       
node2.example.com     287m         7%        6495Mi          41%  
node3.example.com     100m         2%        9515Mi          60%       

Step 4

Next lets look at what sort of capacity our pods are using in our "logging" project.

# oc adm top pods -n logging

NAME                                      CPU(cores)   MEMORY(bytes)   
logging-fluentd-2mcgk                     11m          115Mi           
logging-fluentd-nqlsk                     40m          108Mi           
logging-es-data-master-vprbj3wm-1-zrcwp   205m         5117Mi          
logging-kibana-1-rg7rr                    8m           104Mi           
logging-fluentd-8ltfv                     11m          88Mi            
logging-curator-1-txd6r                   0m           17Mi            
logging-fluentd-k9g7m                     11m          126Mi           

You can also list all the pods in your whole cluster by using the --all-namespaces switch.

# oc adm top pods --all-namesapaces

Conclusion

In this lab you learned how to use oc adm top to analyze resources managed by the platform and present current usage statistics.