OCI Foundations - Compute

Introduction

• Virtual Machines / Bare Metal servers / Dedicated Host (will run ONLY your VMs, not shared with other customers).
• Can choose Intel, AMD or ARM.
• Preemptible VMs - short term batch jobs, lower cost.

Flexible Shape: Choose cores and RAM.

Instance Basics

Dependencies:

• A VCN is required
• The host's VNIC is placed in the VCN
• Boot image and data on remote storage
• Connected to Block Storage

Live migrate: transparent move on a failure to another host, applications keep running

Use Cloud Shell to generate SSH keys: ssh-keygen -b 2048 -t rsa -d test_key

Create instance: upload public key to allow SSH login: ssh -l test_key opc@<ip>

Scaling

Vertical Scaling: up/down shapes (CPUs, RAM)

• Downtime is required
• Best to stop instance first

Horizontal Scaling:

• Add/remove more VMs of the same shape
• Adds reduncancy and capability for load peaks

Autoscaling

• Running instance -> Config -> Instance Pool
• Scaling Rule for min/max size, thresholds for scaling

Oracle Container for Kubernetes (OKE) Cluster

Fully managed, scalable, highly available based on Kubernetes

• Worker Node: machine on which Kubernetes is installed
• Node Pool: group of Nodes
• Pod: Group of one of more containers in a cluster

Control Plane nodes:

• manage the worker node and the Pods in the cluster
• etcd: key/value pair database
• Managed by Oracle

Enhanced CLusters:

• Support all features
• Finanically backed SLAs

Basic Clusters:

• Basic features
• Non-finanical SLAs

Virtual Node:

• Serverless option
• Kubernetes is upgraded and security patches are applied while respecting application availability
• Managed by Oracle
• Can only be created in Enhanced Clusters

Managed Nodes

• Customer is responsible for managing the nodes
• Customer is responsible for upgrading Kubernetes and the capacity
• Can be created in Basic and Enhanced Clusters

Container Workloads

Container Instances: A simple way to run a container application without the complexity of Kubernetes

• Users supply the container image and resource limits for containers
• Serverless offering

Oracle Functions

Write code in a runtime and the cloud provider executes the code. Not even a container is needed.

• Function as a Service
• Event Driven Architecture
• Billed only for when the function runs
• Powered by OpenFn

Process:

• Push container to registry
• Configure trigger function (CLI, API, OCI events)
• Code only runs when triggered