Aladdin: a maxflow model based scheduler

Aladdin is a new apporach to cluster scheduling that models the problem of scheduling as a network flow optimization problem. Aladdin aims on providing:

• Max-number tasks scheduling
• Lower latency on scheduling decisions
• Inter tasks constraint support

Aladdin is an Go implementation of the scheduler. The goal of this project is to integrate Aladdin in Kubernetes as an alternative scheduler.

Current State of Project:

The project so far is an early stage prototype with max-number tasks scheduling and Kubernetes integrate implemented. Aladdin uses the Kubernetes API allowing it to batch schedule pods. Currently the implementation has no support for inter tasks constraint, and we will implement it for the foreseeable future.

Trying it Out:

To get the scheduler up and running there are 2 ways to currently test it out.

Running on a live kubernetes cluster in a container

Step 1:

You need to clone this repo, and move to <RepoPath>/cmd/kube-scheduler/, and build this repo with commandenv GOOS=linux GOARCH=amd64 go build scheduler.go

Step 2:

You can test the scheduler by running it inside of a container on the kubernetes master node. You can build the image from build/Dockerfile yourself, before that you need to move excutable scheduler binary file to /build path, then build image with command.

docker build -t aladdin-scheduler:1.0 .
docker --push larryyang/aladdin-scheduler:1.0

Step 3:

We created a Deployment configuration file and ran it in an existing Kubernetes cluster, using the Deployment resource rather than creating a Pod resource directly because the Deployment resource can better handle the case of a scheduler running node failure. Here is the Deployment configuration example, saved as the aladdin-scheduler.yaml file:

apiVersion: v1
kind: Deployment
metadata: 
 labels:
  component: scheduler
  tier: control-plane
 name: custom-scheduler
 namespace: kube-system
spec:
  selector:
    matchLabels:
      component: scheduler
      tier: control-plane
  replicas: 1
  template:
    metadata:
      annotations:
        scheduler.alpha.kubernetes.io/critical-pod: ""
creationTimestamp: null
      labels:
        component: scheduler
        tier: control-plane
      name: aladdin-scheduler
      namespace: kube-system
    spec:
      containers:
        - command:
          - /usr/local/bin/aladdin-scheduler
          - --address=0.0.0.0
          - --scheduler-name=aladdin-scheduler
          - --kubeconfig=/etc/kubernetes/scheduler.conf
          - --leader-elect=false
          - --port=10253
          image: aladdin-scheduler:1.0
          imagePullPolicy: IfNotPresent
          livenessProbe:
            failureThreshold: 8
            httpGet:
              path: /healthz
              port: 10253
              scheme: HTTP
            initialDelaySeconds: 15
            timeoutSeconds: 15
          name: custom-scheduler
          resources:
            requests:
              cpu: 100m
            volumeMounts:
              - mountPath: /etc/kubernetes/scheduler.conf 
                name: kubeconfig
                readOnly: true
      hostNetwork: true
      priorityClassName: system-cluster-critical 
      volumes:
        - hostPath:
            path: /etc/kubernetes/scheduler.conf
            type: FileOrCreate
          name: kubeconf

Step 4

Create Deployment resource in Kubernetes cluster

kubectl create -f aladdin-scheduler.yaml

Running on a live kubernetes cluster using Goland IDE

Step 1:

You need to clone this repo, and make it a Go Project which means that you need to make upper directories src/ and pkg/. And then you need to make a sub directory k8s.io/ in src/ directory move Aladdin project to k8s.io/ directory, renaming aladdin/ as kubernetes/. After you finish all these, the path of Project should be like this: <GolandRootPath>/src/k8s.io/kubernetes

Step 2:

Open the repo kubernetes/ in Goland IDE, then add arguments for go build command in Run——>Edit Configurations——>go build——>go build scheduler.go——>Program arguments, the arguments is --kubeconfig <GolandRootPath>/src/k8s.io/kubernetes/cmd/kube-scheduler/config --leader-elect=false --scheduler-name flow-scheduler, click OK.

Step 3:

You need to replace Config file for cmd/kube-scheduler/config using your Kubernetes cluster certifacation file.

Step 4:

Add <Kubernetes master IP address> <domain name in Config file> in your /etc/hosts file, just like 39.107.241.0 iZ2ze86eplnjdkjfil6oahZ.

Step 5:

Run cmd/kube-scheduler/schduler.go