Containers Revealed:
As Easy as Tic-Tac-Toe
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Latin America Oracle User Group Community Tour '23
July 29 - August 16, 2023
Sean Scott
Oracle ACE Director
DoK Community Ambassador
Managing Principal Consultant
@oraclesean
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sean.scott@viscosityna.com
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DATABASE RELIABILITY ENGINEERING ⁘ DEVOPS & AUTOMATION
HIGH AVAILABILITY ⁘ BUSINESS CONTINUITY ⁘ DISASTER RECOVERY
MODERNIZATION ⁘ OBSERVABILITY ⁘ ENGINEERED SYSTEMS
AutoUpgrade ⁘ Zero Downtime Migrations ⁘ Patching
Real Application Clusters ⁘ Data Guard ⁘ Sharding
Docker/Containers ⁘ Terraform ⁘ Ansible
Exadata ⁘ Oracle Database Appliance
AHF ⁘ TFA ⁘ GIMR ⁘ CHA
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Sean Scott
Oracle ACE Director
DoK Community Ambassador
Managing Principal Consultant
@oraclesean
linkedin.com/in/soscott/
sean.scott@viscosityna.com
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An Open Community for
Data on Kubernetes
https://dok.community
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Oracle on Docker
Running Oracle Databases in Linux Containers
Download a free sample chapter:
https://oraclesean.com
20% Discount Code: OracleDocker
https://link.springer.com
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What Are Containers?
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Containers are like lightweight Virtual Machines, right?
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Three full operating systems Three application/executable directories
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Three full operating systems Three application/executable directories
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13 Oracle Databases on a Laptop
2018 MacBook Pro 15", 2.2GHz 6-core Intel Core i7, 16GB, 1TB SSD
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Virtual Machines: Bootable OS, often heavy
Containers: Support one application or service
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Virtual Machines: Bootable OS, often heavy
A 100-page book of games & puzzles
Containers: Support one application or service
A sheet of paper with a Tic-Tac-Toe grid
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vo • cab • u • lar • y
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Games have structured playing
surfaces and rules.
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Services deliver games to players.
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Images include the
game rules and playing surface.
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Images are a minimal filesystem & metadata
needed to run a service.
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Running an image starts a Container.
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A container is:
A process on a host, and;
A Union Filesystem.
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Container processes are isolated.
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A Union Filesystem has three layers:
A Merge or Union Layer.
An Upper Layer.
A Lower Layer.
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A Union Filesystem has three layers:
A Merge or Union Layer: The game.
An Upper Layer: The container.
A Lower Layer: The image.
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The Upper (merge) layer isn't "real."
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The Upper (merge) layer isn't "real."
It's a perceived (calculated) union of:
• The game board & rules
• Game play
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Containers persist state (moves) in the
run-time layer of its Union Filesystem.
Containers are stateful.
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Deleting a container removes its
Union Filesystem (and its run-time layer).
Containers are Ephemeral
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Images are immutable and never change.
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Stalemate!
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Images are immutable and can't persist state
information. They are stateless.
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Images = Static
Containers = Living
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Containers are Magic!
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How much space do three containers use?
500MB
+ 500MB
+ 500MB
500MB
500MB
+ 500MB
+ 500MB
1,500MB
500MB
500MB 500MB
+
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Multiple identical containers will share an image.
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A Dockerfile is a recipe for building images.
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Paper
Tic-Tac-Toe Grid
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Image layers are modular and reusable.
Layers can be cached and reused
among multiple images.
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Paper
Game of Sums 3x3 Sudoku
Tic-Tac-Toe Grid
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Base Linux OS
TensorFlow Flask
Python
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Build Context
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Context is a pantry of image ingredients.
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Base Linux OS
RU 19.15 RU 19.16
Oracle Database 19.3.0
RU 19.17 RU 19.18
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Ignore files limit and control the build context.
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Images are the minimum collection of files
and directories needed to run an application.
They are immutable and stateless.
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Running an image creates a container
as the upper layer of a union filesystem,
superimposed over the image, and
starts an isolated process for container activity.
Containers are stateful, ephemeral,
and persist data to the filesystem.
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All containers share the same image,
allowing them to achieve tremendous capacity.
Containers are efficient and fast because
there is nothing to “boot” or copy.
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Building images creates a layer for each step.
Layers can be cached and shared
between images.
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Images are portable across clouds,
operating systems, and container engines.
Images run identically:
• in Docker, Podman, Kubernetes, etc.;
• on Mac, Windows, or Linux;
• and in any Cloud!
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Contact Me
sean.scott@viscosityna.com
https://linktr.ee/oraclesean