1. Understanding and Improving Server Performance
Alan Doerhoefer Timothy Hanson
Tableau Software Inc.

2. How To Improve Server Performance
Steps to Great Performance
Learn the architecture
Use appropriate hardware
Use distributed server
Use server extracts
Tune
Monitor
Troubleshoot
Learn the types of views
Understand the load test results

3. Understand Server Architecture
Tableau Server
Data Sources
Load Balancer
Web App
VizQL
Processes
Application State
Repository
Web App
Application (WG)
Processes
Tableau
Professional

4. Use Appropriate Server Hardware
Good Server for performance:
Windows Server 2003 or bit
16 GB RAM
Fast RAID-5 Drives
Gigabit Network Card
8 Fast CPU cores

5. Use Appropriate Server Hardware
But Tableau Server will work on lower class hardware:
Windows Server bit
2 GB RAM
Any type of drive
100 Mb Network Card
2 slow CPU cores

6. Use Distributed Server
Worker 1
VizQL or WG
Processes
VizQL or WG
Processes
VizQL or
Application
Processes
Main
Load Balancer
Worker N
Application State
Repository
Worker 2
VizQL or WG
Processes
VizQL or WG
Processes
VizQL or
Application
Processes

7. Use Distributed Server
Installation is fast and easy
We have pre-installed the small worker installer on 2 machines, and run a normal non-distributed install on the main machine (distributed1).
Show status screen of server with one machine to compare before and after, then stop server.
Start tabconfig to enter server IPs. Note the new tabs “Servers” and “SSL.”

8. Use Distributed Server
Installation
4. Enter IPs for distributed2 (8 App Servers) and distributed3 (8 VizQLs); set “This Machine” to 0 processes; click OK.
5. While init is running, mention that worker installer is 8 Mb, installs in a few minutes; all you need to enter is the main server’s IP address.
6. When init completes, start server, then show status screen again showing multiple servers.

9. Use Distributed Server
Determining the number of server processes
Use 2 X the number of processor cores
Example
3 server cluster (2 workers)
8 cores per machine
Use 2 x 8 = 16 App processes on one worker
Use 2 x 8 = 16 VizQL processes on the other worker

10. Use Server Extracts New in 5.0
A database that stores “extracts” of user data locally and efficiently
Performance is improved since data is local and indexed
Data can be filtered and aggregated as part of the extract
Can be set to refresh data sources automatically on a schedule
The following extract database types are supported:
Built-In
Postgres
MySQL
Microsoft SQL Server
Please attend Extracts: Fast Data To Go Thurs. 11 am for more extract details
A scheduled extract can improve performance by allowing slow database queries to be run automatically at night.
Aggregation of the extracted data can improve performance by reducing the size of the data.

11. Tune the OS
Windows 2003 Server (SP1 or Later) TCP Setting Not an issue in Windows 2008 Server
Set SynAttackProtect to zero:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters] "SynAttackProtect"=dword:
Disable other processes

12. Tune the Server Session Timeouts WG Session VizQL Session
Can be changed in the configuration file Tableau Server\config\tabsvc.yml
WG Session
Default is 4 hours
To change it to 1 hour add this to tabsvc.yml: wgserver.session.idle_limit: 60
VizQL Session
Default is 2 hours
To change it to 30 minutes add this to tabsvc.yml: vizqlserver.session.expiry.timeout: 30

13. Monitor Server
Server Status
Demo

14. Monitor Server
Server Activity
Demo

15. Monitor Server
User Activity
Demo

16. Troubleshoot Server Apache logs
Contains information about every request to server at the HTTP request level

17. Troubleshoot Server WG logs and VizQL logs
Contains details of each operation performed by the server

18. Troubleshoot Server tabadmin ziplogs command
collects all logs – even on a distributed cluster – into one archive

19. Understand View Types and Performance
Three Types Of Views:
1. Fast
- Fast query
- Fast rendering
2. Query-bound
- Slow query
- Fast Rendering
- Same as Fast once query is cached
3. CPU-bound
Render-Intensive
Uses the most CPU
Example: text tables with thousands of cells

20. Understand the Load Test Results
Capabilities of:
1 machine
3 machines
5 machines
* Note that these tests show results from a specific test configuration and should not be taken as a guarantee of client response times. These benchmark results were returned in a controlled lab environment, without other applications running during execution. Actual results will vary based on load type, hardware, network speed, browser settings, and database performance.

21. Understand the Load Test Results
Initial View Load Times
Effect of caching
5 servers in our load tests served 2,250 named users, or 225 concurrent users
Note effect of caching in the 3-sever case
Load test machines were identical 8-core servers with 16 GB RAM, 4x15K 73GB, and 2.5ghz Xeon processors.

22. Understand the Load Test Results
Caching
- Pre-load views whenever possible to improve initial load times

23. Summary Keys to Performance: - Understand view types
- Understand and utilize the distributed architecture
- Use server extracts
- Learn how to monitor and investigate