Task Topology Plugin User Guide

Environment setup

Install volcano

Refer to Install Guide to install volcano.

Update scheduler configmap

After installed, update the scheduler configuration:

kubectl edit configmap -n volcano-system volcano-scheduler-configmap

Register task-topology plugin in configmap

kind: ConfigMap
apiVersion: v1
metadata:
  name: volcano-scheduler-configmap
  namespace: volcano-system
data:
  volcano-scheduler.conf: |
    actions: "enqueue, allocate, backfill"
    tiers:
    - plugins:
      - name: priority
      - name: gang
      - name: conformance
    - plugins:
      - name: drf
      - name: predicates
      - name: task-topology
        arguments:
          task-topology.weight: 10
      - name: proportion
      - name: nodeorder
      - name: binpack

Running Jobs

Take tensorflow job as sample.

Install kubeflow/tf-operator

Refer to Install Guide to install kubeflow, tf-operator included.

Edit yaml of tfjob

1. add annotations in volcano job or tensorflow job in format below.

   1. affinity annotation indicates that tasks have connections between each other, so they should be set on same nodes;
   2. anti-affinity annotation indicates that tasks do not have connections between each other, so they should be set on different nodes;

   3. task-order annotation indicates the order that tasks should be allocated. For example, ps,worker means scheduler should schedule ps tasks first. After all ps tasks were allocated, scheduler started to schedule worker tasks. This annotation is not a required field.

          volcano.sh/task-topology-affinity: "ps,worker;ps,evaluator"
          volcano.sh/task-topology-anti-affinity: "ps;worker,chief;chief,evaluator"
          volcano.sh/task-topology-task-order: "ps,worker,chief,evaluator"