86 lines
3.1 KiB
Markdown
86 lines
3.1 KiB
Markdown
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# Resource Consumer
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## Overview
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Resource Consumer is a tool which allows to generate cpu/memory utilization in a container.
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The reason why it was created is testing kubernetes autoscaling.
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Resource Consumer can help with autoscaling tests for:
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- cluster size autoscaling,
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- horizontal autoscaling of pod - changing the size of replication controller,
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- vertical autoscaling of pod - changing its resource limits.
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## Usage
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Resource Consumer starts an HTTP server and handle sent requests.
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It listens on port given as a flag (default 8080).
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Action of consuming resources is send to the container by a POST http request.
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Each http request creates new process.
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Http request handler is in file resource_consumer_handler.go
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The container consumes specified amount of resources:
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- CPU in millicores,
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- Memory in megabytes,
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- Fake custom metrics.
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###Consume CPU http request
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- suffix "ConsumeCPU",
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- parameters "millicores" and "durationSec".
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Consumes specified amount of millicores for durationSec seconds.
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Consume CPU uses "./consume-cpu/consume-cpu" binary (file consume-cpu/consume_cpu.go).
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When CPU consumption is too low this binary uses cpu by calculating math.sqrt(0) 10^7 times
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and if consumption is too high binary sleeps for 10 millisecond.
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One replica of Resource Consumer cannot consume more that 1 cpu.
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###Consume Memory http request
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- suffix "ConsumeMem",
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- parameters "megabytes" and "durationSec".
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Consumes specified amount of megabytes for durationSec seconds.
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Consume Memory uses stress tool (stress -m 1 --vm-bytes megabytes --vm-hang 0 -t durationSec).
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Request leading to consuming more memory then container limit will be ignored.
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###Bump value of a fake custom metric
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- suffix "BumpMetric",
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- parameters "metric", "delta" and "durationSec".
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Bumps metric with given name by delta for durationSec seconds.
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Custom metrics in Prometheus format are exposed on "/metrics" endpoint.
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###CURL example
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```console
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$ kubectl run resource-consumer --image=gcr.io/google_containers/resource_consumer:beta --expose --service-overrides='{ "spec": { "type": "LoadBalancer" } }' --port 8080
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$ kubectl get services resource-consumer
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```
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There are two IPs. The first one is internal, while the second one is the external load-balanced IP. Both serve port 8080. (Use second one)
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```console
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$ curl --data "millicores=300&durationSec=600" http://<EXTERNAL-IP>:8080/ConsumeCPU
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```
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300 millicores will be consumed for 600 seconds.
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## Image
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Docker image of Resource Consumer can be found in Google Container Registry as gcr.io/google_containers/resource_consumer:beta
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## Use cases
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###Cluster size autoscaling
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1. Consume more resources on each node that is specified for autoscaler
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2. Observe that cluster size increased
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###Horizontal autoscaling of pod
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1. Create consuming RC and start consuming appropriate amount of resources
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2. Observe that RC has been resized
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3. Observe that usage on each replica decreased
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###Vertical autoscaling of pod
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1. Create consuming pod and start consuming appropriate amount of resources
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2. Observed that limits has been increased
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[]()
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