1. DEA Will Be Your New Best Friend!
Jared Karney

2. A Little About Me PFE – Data and AI at Microsoft @sqlknowitall

3. True Story Currently running SQL Server 2012
Currently running Windows Server 2012 R2
Want to move to new hardware
Upgrade Windows Server to 2016
Upgrade SQL Server to 2016
How do we verify that the changes in 2016 will not cause performance issues?

4. DEA What is DEA? How does DEA work?
How do I install and configure DEA?
What are the steps to using DEA?

5. What is DEA? Database Experimentation Assistant
New A/B Testing solution for SQL Server
Automated script to set up workload capture and replay of production database (using existing SQL server functionality Distributed Replay & SQL tracing)
Perform statistical analysis model on traces collected using both old and new instances
Produces a visual report with drilldown detail

6. DEA Steps Capture workload from source server
Replay workload on Target 1 (baseline or new source)
Replay workload on Target 2 (“changed” server)
Analyze replays from Target 1 and Target 2

7. Prerequisites Tool Distributed Replay Database Instances
Windows 7+, x64
Windows Server 2012+, x64
.NET Framework 4.5+
Distributed Replay
Replay Controller
At least 1 Replay Client
Database Instances
1 instance for analysis
Source database
Target database

8. Step 1 – Collect workload
Take a backup as close to the start of your collection as possible
User running DEA must have access to collection server
User running DEA must have write access to local folder collecting the workload trace

9. DEA In Practice
Capture a production workload

10. Step 2 – Replay Workload on Target 1
Configure Distributed Replay
Restore database to before workload capture
Run replay

11. Configuring Distributed Replay
Controller
Service account must have access to read the collected trace
Service account for Client should be in the Distributed COM Users security group
Component Services must grant permissions to Client Service Account and user account running DEA
Launch and Activation
Access

12. Configuring Distributed Replay
Controller
Firewall must allow inbound connections for client and controller
%ProgramFiles% (x86)\Microsoft SQL Server\140\Tools\DReplayClient\DReplayClient.exe
%ProgramFiles% (x86)\Microsoft SQL Server\140\Tools\DReplayController\DReplayController.exe

13. Configuring Distributed Replay
Controller
Make sure SQL Server is patched! (I’ve had issues with Distributed Replay on RTM)

14. Configuring Distributed Replay
Client(s)
Service account should be in the Distributed COM Users security group
Firewall must allow inbound connections for client and controller
%ProgramFiles% (x86)\Microsoft SQL Server\140\Tools\DReplayClient\DReplayClient.exe
%ProgramFiles% (x86)\Microsoft SQL Server\140\Tools\DReplayController\DReplayController.exe
SQL Target/Source
Make sure DReplay client account has access to SQL Server
SQL Server Service account must have rights to write to collection folder
Final Steps
Start services (controller first, then clients) and verify client registered with controller
C:\Program Files (x86)\Microsoft SQL Server\140\Tools\DReplayClient\Log
C:\Program Files (x86)\Microsoft SQL Server\140\Tools\DReplayController\Log (if necessary)

15. Proper DReplay Client Log

16. DEA In Practice
Configuring DReplay Prerequisites

17. Replaying Trace on Target 1
Make sure you restore your backup
Verify that the setup and configuration are exactly as you need it
Set up replay and run it

18. Replaying Trace on Target 2
Make sure you restore your backup
Verify that the setup and configuration are exactly as you need it for your second target
Set up replay and run it

19. DEA In Practice
Replaying a workload

20. Step 3 – Analyzing Your 2 Captures
Install prerequisites on DEA client machine
R for Windows -
R Interop -
Set up the analysis and run it

21. Analysis Algorithm : Finding Regressed Queries

22. Looking at Results

23. DEA In Practice
Analysis

24. In Summary What is DEA? How does DEA work?
Microsoft’s solution for helping you analyze the impact of changes on a database
How does DEA work?
It takes a workload capture and replays it against a control and a change and then compares them for you
How do I install and configure DEA?
Install and configure Distributed Replay, R for Windows, R-Interop, and DEA
What are the steps to using DEA?
Capture, Replay, Replay, Analyze

25. Resources
Download DEA -
DEA Blog -
Configuring Dreplay -