1. Docker for DBAs
SQL Saturday 8/17/2019

2. About Me –Brad(ley) Nielsen
11+ years development experience
Masters in Human Computer Interaction
IU Graduate Certificate in Data Science
MCSE in Business Intelligence
Microsoft Professional Program for Data Science
1+ Years working with Docker

3. Contents Docker What is it? How to use it? Manage State in Docker
SQL Server + Docker
Docker benefits
Big topic. Try to smooth over nuances where possible. Look at a narrow slice of the ecosystem.
Most Docker documentation is shrouded in app dev talk

4. What is Docker?
Open platform for developing, shipping, and running applications.
Main Benefits
Write once deploy anywhere
Improved security
Fast deployment
Efficient resource utilization
Start vague and get more detailed as we go
Understand whole to understand the pieces.

5. Container Analogy Container imagery is everywhere.
Why are they called containers?
Analogy to shipping containers.
Before moving stuff was hard.
Different shapes and sizes.
Containers standardized that.

6. Container Analogy
Docker containers aim to do the same with applications

7. Docker Components Image Container Registry Host Binary “executable”
Running “executable”
Registry
Versioned image storage and sharing
Host
Resource that spawns and manages containers
Rough analogy of an “executable”
Container = double click and run “executable”

8. Image Overview
Images are layered, read-only, snapshots of applications
Contains
Application
Dependencies (DLLs, Jars, libraries, etc.)
Any other file specified by build (Config files, etc.)
Does not include
Operating system files
Unit of deployment in Docker
Relying on the operating system is why Docker is so much faster.

9. Image Overview
Images are built in layers to save space and provide reusability.
Union File system
Take note of the R/W layer
R/W goes away when container reboots
Note the R/O layers

10. Container Overview Container = Image + R/W Layer + Process(es)
Images may be used to create one to many containers
Processes within container are isolated
Much less resource usage vs VM
From a processes point of view they appear to be alone. (Various OS tricks.)
Containers don’t recreate OS resources

11. Container Overview
Containers are to applications as virtual machines are to operating systems
Don’t lean too heavily in VM analogy.
Light weight VM good analogy but not much in common technically
Container
Virtual Machine

12. Registry Overview Stores, shares, and versions Docker images.
Repository = 1 type of image
Registry = many repositories
Types
Local
Private
Public
Private = usually a corporate registry
Repository = Table
Registry = DB

13. Host Overview Docker Daemon Azure Other Orchestrators
Azure App Service
Azure Kubernetes Service
Azure Container Instance
Other Orchestrators
Docker Swarm
Elastic Container Service
HashiCorp Nomad
Docker Daemon = single machine
Orchestrator = advanced multi container deployments. Usually cluster based

14. Azure Host Overview Azure Container Instances Azure App Service
Container equivalent to Azure Functions
Per second billing
Azure App Service
Allows you to run any web stack in App Service
One to many containers
Same frills as other App Service
Azure Kubernetes Service
For complicated multi container services
ACI = Serverless
App Service = Web apps
Azure K S = Heavy duty enterprise cluster
Couple others, but those are the main ways

15. Put It All Together
We’ll go through these steps in a demo

16. How to use it? DEMO Build Push to Repository
Deploy to Azure Container Instances
Deploy to Azure App Service

17. Let’s talk about state in Docker
Containers are stateless
Most apps need some sort of state management
Databases are very much stateful
What is state?
Things you need to save if the app reboots

18. Option 0: Use a database Most Docker apps are stateless
Rely on a database that lives outside the cluster
Obviously not going to work when your app is a database

19. Option 1: Embrace stateless
Useful for testing
Fast spin up and tear down
Changes to data do not persist through reboots
Great for QA and Testing

20. Option 2: Volumes Conceptually like network drives for containers
Stored in host file system, but managed by Docker
Can also mount remote storage such as Azure Files
Default is folder on the host system

21. Option 3: StatefulSets Kubernetes only
Uses Volume claims (Docker Volumes for clusters)
Other advanced features for stateful applications
Other orchestrators have similar features

22. SQL Server on Docker Linux SQL Server 2017 or 2019
Windows SQL Server Express (limited support)
Operate identically to their VM counterparts

23. SQL Server on Docker
DEMO
Deploy to Azure App Service

24. SQL Server Kubernetes HA Groups
Easy deployment… if you know Kubernetes

25. SQL Server 2019 Big Data Cluster
•A compute pool is a group of SQL Server pods used for parallel ingestion of data from an external source–such as Oracle, HDFS, or another SQL Server–and for cross-partition aggregation and shuffling of the dataas part of a query.
•A storage pool is a group of pods containing SQL Serverengine, HDFS data node, and Spark containers. This provides the scalable storage tier along with the collocated compute for SQL Server and Spark right next to the data.
•A data pool is a group of SQL Serverenginepods that is used either to cache data from an external source or to store an incoming stream of append-only data. In either case,the data is partitioned and distributed across all of the SQL Server instances in the pool
Beware version 1

26. Docker Benefits Higher server density over VMs
Reduce errors moving from development to production
Easy app scaling
Easy deployment
Security
DevOps integration
Worked on my machine

27. Docker Drawbacks Large learning curve
Orchestrators (Kubernetes, etc.) make this curve worse
May be overkill for smaller applications
Caution is recommended for production DB deployments