Karpenter @LightSpeed

Transcript

1. Karpenter @ Lightspeed
2. Charles Guertin Responsible for the reliability of three different Lightspeed Hospitality products Site Reliability Expert @ Lightspeed
3. 1 2 3 4 5 3 Deploying Karpenter Karpenter Provisioning Node Consolidation Cluster Overprovisioning Q&A Agenda
4. Deploying Karpenter
5. Deploying Karpenter
6. Karpenter Provisioning
7. Karpenter Provisioning • Different provisioners for each environment • Settings based on needs per environment, reliability requirements, capacity & costs
8. Node Consolidation
9. Node Consolidation • Allows rebalancing of your cluster nodes ◦ When enabled, Karpenter will optimize capacity so that you don’t have under-utilized nodes • Cost savings ◦ Lower costs due to consolidation / packing ◦ Less nodes = less money spent • Requirements ◦ Resources requests must be set, in order for Karpenter to properly resize a cluster
10. Node Consolidation • What about services that can’t tolerate rescheduling? ◦ Use the do-not-evict=true annotation ◦ Karpenter will not rebalance nodes running pods marked with this annotation • Scheduled Node consolidation in dev environment ◦ Enable consolidation at night ◦ Reduce rebalancing in busy clusters during the day - so that devs aren’t affected by it
11. Cluster Overprovisioning
12. Cluster Overprovisioning • Complimentary to Karpenter, separate Deployment ◦ image: registry.k8s.io/pause ◦ Each replica of this deployment fills a single node • Extra empty Nodes stand-by ◦ These nodes are waiting for Karpenter scale up so that new workloads can be scheduled on these fresh nodes ◦ This removes the waiting time of creating new nodes for upscaling workloads • TL;DR: Faster workload upscaling ◦ Karpenter upscaling time = 2 minutes ◦ Overprovisioning upscaling time = 0 minutes.
13. 13 Cluster Overprovisioning - how it works Node 2 Stand-by 1 Node 3 Node 4 Node 1 Stand-by 2
14. Q&A
15. Thank you :)