Luna Configuration

Labels, Annotations, and Exclusions

Labels

In order for Luna Manager to manage the pods scheduling, the following label must be applied:

metadata:
  labels:
    elotl-luna: "true"

Instance family exclusion(s)

It’s possible to instruct Luna to avoid starting a given instance family node for a given workload. Luna will look for a following annotation in the pod:

metadata:
  annotations:
    node.elotl.co/instance-family-exclusions: "t3,t3a"

This will prevent Luna from starting any t3. or t3a. instance type for this pod.

Instance family inclusion(s)

It’s also possible to instruct Luna to only use specific nodes from a given instance family for a given workload. Luna will look for a following annotation in the pod:

metadata:
  annotations:
    node.elotl.co/instance-family-inclusions: "c6g,c6gd,c6gn,g5g"

This will restrict Luna to using choosing from the following c6g.,c6gd.,c6gn.,g5g. instance types for this pod.

note

Pods with either of these annotations will be bin-selected, regardless of the pod’s resource requirements.

AWS Fargate

If you would like Luna to run your workload on Fargate nodes, please include the following annotation in your configuration so that Luna can identify your preference:

metadata:
    annotations:
       node.elotl.co/instance-offerings: "fargate"

Please note that this feature is specific to AWS. Additionally, during the Luna deployment process, you must indicate that you would like to use Fargate in order to utilize this feature.

GPU SKU annotation

It’s possible to instruct Luna to start an instance with a specific graphic card.

metadata:
  annotations:
    node.elotl.co/instance-gpu-skus: “v100”

This will start a node with a V100 GPU card.

note

Each pod with this annotation will be bin-selected, regardless of the pod’s resource requirements.

Additional Helm Values

In most cases these do not need to be changed.

1. labels is a list of comma separated key value pairs: key1=value1\,key2=value2pods with any of the labels will be considered by Luna. The default value is elotl-luna=true.
2. binSelectPodCpuThreshold and binSelectPodMemoryThreshold are parameters controlling bin-selection (see below)
3. binPackingNodeCpu, binPackingNodeMemory, binPackingNodeMinPodCount, and binPackingNodeTypeRegexp are parameters controlling bin-packing (see below)
4. clusterGPULimit is an integer that specifies the GPU limit of the cluster if gpu count in the cluster reaches this number, luna will stop scaling up GPU nodes

The keys and values are passed to the deploy script as the follows:

./deploy.sh <cluster-name> <cluster-region> \
    --set binSelectPodCpuThreshold=3.0 \
    --set binSelectPodMemoryThreshold=2G \
    --set binPackingNodeCpu=3250m \
    --set binPackingNodeMemory=7Gi \
    --set binPackingNodeMinPodCount=42 \
    --set binPackingNodeTypeRegexp='^t3a.*$' \
    --set labels='key1=value1,key2=value2'

Bin-selection

Bin-selection means running the pod on a dedicated node.

When a pod’s requirements are high enough Luna provisions a dedicated node to run it. Luna uses the pod’s requirements to determine the node’s optimal configuration, add a new node to the cluster, and run the pod on it. If the pod’s cpu requirement is above binSelectPodCpuThreshold and/or if the pod’s memory requirement is above binSelectPodMemoryThreshold, the pod will be bin-selected and run on a dedicated node.

Bin-packing

Bin-packing means running the pod with other pods on a shared node.

binPackingNodeCpu and binPackingNodeMemory let you configure the shared nodes’ requirement. If you have an instance type in mind, set these paramaters slightly below the node type you are targeting, to take into account the kubelet and kube-proxy overhead. For example if you would like to have nodes with 8 VCPU and 32 GB of memory, set binPackingNodeCpu to "7.5" and binPackingNodeMemory to "28G".

If a pod’s requirements are too much for bin-packing nodes, an over-sized node will be provisioned to handle this pod. For example if configured bin-packing typically have 1 VCPU, and a bin-packed pod needs 1.5 VCPU, a node with 1.5 VCPU will be provisioned by Luna to accommodate this pod. This will only happen when the bin selection thresholds are above the bin packing requirements.

Each node type can only run a limited number of pods. binPackingNodeMinPodCount lets you request a node that can support a minimum number of pods.

binPackingNodeTypeRegexp allows you to limit the instances that will be considered. For example is you would only like to run instances from "t3a" family in AWS you would do: binPackingNodeTypeRegexp='^t3a\..*$'