<p>The DevOps toolkit 2.3 book by Victor Farcic goes into some detail on this.</p>

<h1>What You Should Understand</h1>

<ul>
<li>You as a developer specify whatever requests/limits you like initially.</li>
<li>These values have no baring on reality.</li>
<li>In order to get "real" values, you must monitor your application's real resource usage.</li>
<li>This is best done through a monitoring tool like prometheus, instana, datadog etc.</li>
<li>E.g. in instana, I can see that I have 512MB set up for a pod's requests, 2G for its limits, but the pod only has one container currently taking 57MB.</li>
<li>But I can't just use 60MB as a value now... I need to load test my application and see how it behaves under real/stressed circumstances.</li>
<li>Then you review these values and you can adjust the requests/limits accordingly.</li>
</ul>

<h1>Determine Usage Without a Monitoring Tool</h1>

<p>You can use some kubectl commands to get these values as a one off (it's annoying at scale).  Here is an example of a different app I have running.</p>

<p>Notice that requests/limits are set to 1/4-2 CPUs and 4G-8G memory.  But the container is really using almost no CPU and 1.198G memory.  If I load tested this and those values did not move up, I would need to change them.  But I have load tested it and know that they would go up towards these realistic requests/limits, so it's okay.</p>

<pre><code>$ kubectl describe pod -n gazelle gazelle-ws-0-0-1-6d67cffcf-lvlhk

...
    Limits:
      cpu:     2
      memory:  8Gi
    Requests:
      cpu:      250m
      memory:   4Gi

$ kubectl top pod gazelle-ws-0-0-1-6d67cffcf-lvlhk -n gazelle --containers

POD                                NAME         CPU(cores)   MEMORY(bytes)   
gazelle-ws-0-0-1-6d67cffcf-lvlhk   gazelle-ws   5m           1198Mi 
</code></pre>

CC BY-SA 4.0
2020-02-28T15:18:46.407Z
2020-02-28T15:18:46.407Z
John Humphreys
<p>Say I have 2 nodes for a kubernetes cluster. Both has</p>

<pre><code>2 CPU → 4 Total
2G RAM → 4 Total
</code></pre>

<p>I have 4 pods to shcedule-- no replicas yet, 1 major pod that'll use 80% of resources, other use 5% each.
What resource limits should I specify for these pods?</p>

<p><strong>CURENT USAGE STATS</strong></p>

<pre><code># kubectl top pod --all-namespaces
NAMESPACE       NAME                        CPU(cores)   MEMORY(bytes)
default         pod1-64c455bcf8-mzxqc           1m          122Mi           
default         pod2-6f7b44478b-pn4tt           1m          33Mi            
default         pod3-867c956697-mf6zw           0m          48Mi            
default         pod4-844bd559dd-z96fh           0m          35Mi
</code></pre>

<kubernetes>
How To Determine Min/Max Resources For Kubernetes Pods?
Sollosa
# How To Determine Min/Max Resources For Kubernetes Pods?

(Asked by: username_0 on 2020-02-26)

Say I have 2 nodes for a kubernetes cluster. Both has
2 CPU → 4 Total
2G RAM → 4 Total

I have 4 pods to shcedule-- no replicas yet, 1 major pod that'll use 80% of resources, other use 5% each.
What resource limits should I specify for these pods?
CURENT USAGE STATS
# kubectl top pod --all-namespaces
NAMESPACE       NAME                        CPU(cores)   MEMORY(bytes)
default         pod1-64c455bcf8-mzxqc           1m          122Mi           
default         pod2-6f7b44478b-pn4tt           1m          33Mi            
default         pod3-867c956697-mf6zw           0m          48Mi            
default         pod4-844bd559dd-z96fh           0m          35Mi

**Tags:** kubernetes


---

## 1 answers

### Answer by username_1 on 2020-02-28. Score: 1 | Accepted answer

The DevOps toolkit 2.3 book by Victor Farcic goes into some detail on this.
What You Should Understand

You as a developer specify whatever requests/limits you like initially.
These values have no baring on reality.
In order to get "real" values, you must monitor your application's real resource usage.
This is best done through a monitoring tool like prometheus, instana, datadog etc.
E.g. in instana, I can see that I have 512MB set up for a pod's requests, 2G for its limits, but the pod only has one container currently taking 57MB.
But I can't just use 60MB as a value now... I need to load test my application and see how it behaves under real/stressed circumstances.
Then you review these values and you can adjust the requests/limits accordingly.

Determine Usage Without a Monitoring Tool
You can use some kubectl commands to get these values as a one off (it's annoying at scale).  Here is an example of a different app I have running.
Notice that requests/limits are set to 1/4-2 CPUs and 4G-8G memory.  But the container is really using almost no CPU and 1.198G memory.  If I load tested this and those values did not move up, I would need to change them.  But I have load tested it and know that they would go up towards these realistic requests/limits, so it's okay.
$ kubectl describe pod -n gazelle gazelle-ws-0-0-1-6d67cffcf-lvlhk

...
    Limits:
      cpu:     2
      memory:  8Gi
    Requests:
      cpu:      250m
      memory:   4Gi

$ kubectl top pod gazelle-ws-0-0-1-6d67cffcf-lvlhk -n gazelle --containers

POD                                NAME         CPU(cores)   MEMORY(bytes)   
gazelle-ws-0-0-1-6d67cffcf-lvlhk   gazelle-ws   5m           1198Mi


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