NodeSet Controller

Table of Contents

• NodeSet Controller

  • Table of Contents

  • Overview

  • Design

    • Sequence Diagram

Overview

The nodeset controller is responsible for managing and reconciling the NodeSet CRD, which represents a set of homogeneous Slurm Nodes.

Design

This controller is responsible for managing and reconciling the NodeSet CRD. In addition to the regular responsibility of managing resources in Kubernetes via the Kubernetes API, this controller should take into consideration the state of Slurm to make certain reconciliation decisions.

Sequence Diagram

sequenceDiagram autonumber actor User as User participant KAPI as Kubernetes API participant NS as NodeSet Controller box Operator Internals participant SCM as Slurm Client Map participant SEC as Slurm Event Channel end %% Operator Internals participant SC as Slurm Client participant SAPI as Slurm REST API loop Watch Slurm Nodes SC->>+SAPI: Get Slurm Nodes SAPI-->>-SC: Return Slurm Nodes SC->>SEC: Add Event for Cache Delta end %% loop Watch Slurm Nodes note over KAPI: Handle CR Update SEC-->>NS: Watch Event Channel User->>KAPI: Update NodeSet CR KAPI-->>NS: Watch NodeSet CRD opt Scale-out Replicas NS->>KAPI: Create Pods end %% Scale-out Replicas opt Scale-in Replicas SCM-->>NS: Lookup Slurm Client NS->>+SC: Drain Slurm Node SC->>+SAPI: Drain Slurm Node SAPI-->>-SC: Return Drain Slurm Node Status SC-->>-NS: Drain Slurm Node alt Slurm Node is Drained NS->>KAPI: Delete Pod else NS->>NS: Check Again Later end %% alt Slurm Node is Drained end %% opt Scale-in Replicas