1. Tableau Software Australia
PRESENTED BY
Alan Eldridge
Sales Consultant
Tableau Software Australia

2. ©2011 Tableau Software Inc. All rights reserved.
What we will cover…
Architecture
Scalability & Availability
Caching
©2011 Tableau Software Inc. All rights reserved.
©2011 Tableau Software Inc. All rights reserved.

3. ©2011 Tableau Software Inc. All rights reserved.
Overview
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4. Tableau Desktop Tableau Server
extract
Information
consumers
(Tableau Reader)
connect live
Tableau Desktop
Self-service visual
data analysis
Data Server
Repository
Cache
Presentation
extract
connect live
Security
Web & mobile
users
(Tableau Server interactors)
Management/Automation
Tableau Server
Rapid fire business intelligence

5. ©2011 Tableau Software Inc. All rights reserved.
Architecture
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6. ©2011 Tableau Software Inc. All rights reserved.
Terminology
Process – an instance of a computer program that is being executed. It has its own set of resources (e.g. memory) that are not shared with other processes.
Thread – a process may run multiple threads to perform instructions in parallel. Threads within a process share resources (e.g. memory).
Server – a program running to serve the requests of other programs. The term is also used to refer to a physical computer dedicated to run one or more services.
©2011 Tableau Software Inc. All rights reserved.
©2011 Tableau Software Inc. All rights reserved.

7. Tableau Server

8. Data
Tableau Server
Relational
OLAP
Files

9. Data Tableau Server Clients
Relational
Browser/Mobile
Tableau Desktop
OLAP
Files
Command Line
Tools

10. Gateway/Load Balancer
Data
Tableau Server
Clients
Gateway/Load Balancer
Receives incoming client requests and directs them to the appropriate service for action
Acts as a load balancer, routing traffic round-robin to service instances
Returns HTML responses to client
Single-process; multi-threaded
Relational
Browser/Mobile
Tableau Desktop
OLAP
Files
Command Line
Tools

11. Gateway/Load Balancer
Data
Tableau Server
Clients
Gateway/Load Balancer
Processes logins, content searches, user/group/permission management, and other tasks not related to visualizing data
Works in conjunction with data stored in the Repository
Multi-server; multi-process; multi-threaded
Relational
Browser/Mobile
Tableau Desktop
OLAP
App
Server
Files
Command Line
Tools

12. Gateway/Load Balancer
Data
Tableau Server
Clients
Gateway/Load Balancer
Stores Tableau Server metadata: users, group assignments, permissions, projects, etc.
Also stores flat files used as data sources
Responds to queries from other services when they need metadata
Has a SQL interface so external applications can connect (read-only)
Relational
Browser/Mobile
Tableau Desktop
OLAP
Repository
App
Server
Files
Command Line
Tools
If used, verifies authentication in conjunction with the App Server and Repository
Active Directory

13. Gateway/Load Balancer
Data
Tableau Server
Clients
Data Source Drivers
Gateway/Load Balancer
Provides same functionality as Tableau Desktop, processing requests related to data visualisation
Includes built-in caching (more on this later…)
Multi-server; multi-process; multi-threaded
Relational
Browser/Mobile
Native drivers need to be installed for each data source (32-bit)
VizQL
Server
Tableau Desktop
OLAP
Repository
App
Server
Files
Command Line
Tools
Active Directory

14. Gateway/Load Balancer
Data
Tableau Server
Clients
Data Source Drivers
Gateway/Load Balancer
Data Extract
Host
Relational
Browser/Mobile
VizQL
Server
Tableau Desktop
OLAP
Invoked when a visualisation including a data extract is published
Stores and processes data extracts
Multi-threaded; 64-bit
Repository
App
Server
Files
Command Line
Tools
Active Directory

15. Gateway/Load Balancer
Data
Tableau Server
Clients
Data Source Drivers
Gateway/Load Balancer
Backgrounder
Data Extract
Host
Relational
Browser/Mobile
VizQL
Server
Tableau Desktop
OLAP
Controls tasks that ensure Tableau Server is running smoothly and efficiently
When the Data Extract Host is used, also handles scheduled data refreshes
Multi-server; multi-process
Repository
App
Server
Files
Command Line
Tools
Active Directory

16. Gateway/Load Balancer
Data
Tableau Server
Clients
Data Source Drivers
Gateway/Load Balancer
Data
Server
Invoked when a data source is published via Tableau Desktop
Serves as proxy between requests for data and individual data sources
Enables centralized metadata management for data sources and an additional layer of access control
Allows centralized driver deployment
Allows multiple workbooks to us the same data extract
Multi-server; multi-process; multi- threaded; 32-bit
Backgrounder
Data Extract
Host
Relational
Browser/Mobile
VizQL
Server
Tableau Desktop
OLAP
Repository
App
Server
Files
Command Line
Tools
Active Directory

17. Gateway/Load Balancer
Data
Tableau Server
Clients
Data Source Drivers
Gateway/Load Balancer
Data
Server
Backgrounder
Data Extract
Host
Relational
Browser/Mobile
VizQL
Server
Tableau Desktop
OLAP
Repository
App
Server
Files
Command Line
Tools
Active Directory

18. Server Monitoring
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What you see running…
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20. Scalability & Availability
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21. ©2011 Tableau Software Inc. All rights reserved.
Terminology
Scalability – scalability is about supporting multiple simultaneous actions, not about making a single action faster.
Availability – the ability of a solution to be resistant to component failures. Increasing the availability of a solution will increase the cost.
©2011 Tableau Software Inc. All rights reserved.
©2011 Tableau Software Inc. All rights reserved.

22. ©2011 Tableau Software Inc. All rights reserved.
Terminology
Scale Up – adding more resources (CPU, RAM, etc) to a single server.
Scale Out – adding more resources (CPU, RAM, etc) by adding more servers in a “cluster”.
Multi-Process – adding more throughput by running multiple instances of a process or service. These can be on a single server or can be distributed across multiple servers.
Multi-Threaded – within a process, being able to perform multiple tasks simultaneously across multiple CPUs.
©2011 Tableau Software Inc. All rights reserved.
©2011 Tableau Software Inc. All rights reserved.

23. ©2011 Tableau Software Inc. All rights reserved.
Terminology
Single Point of Failure – within a solution, a component that if it fails will cause the solution to fail as a whole.
Active/Active – when all instances of a multi-process service will process requests.
Active/Passive – when only some instances of a multi- process service will process requests and the other instances are only activated in the event of a component failure.
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©2011 Tableau Software Inc. All rights reserved.

24. ©2011 Tableau Software Inc. All rights reserved.
Server Scalability
Service
Multi-Process
Multi-Threaded
High Availability
VizQL Server
Yes
Active/Active
Data Server
Application Server
Backgrounder No
Data Extract Host
Active/Passive
Repository
Gateway
Manual Failover
©2011 Tableau Software Inc. All rights reserved.
©2011 Tableau Software Inc. All rights reserved.

25. Server Scalability
Primary Node
Active
Repository
Active Extract Host
Gateway
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Starting with a single server – everything is installed on one machine…
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26. Server Scalability
Primary Node
Active
Repository
Active Extract Host
Gateway
Application Server
VizQL Server
Data Server
Backgrounder
Web Server ↑
Scale up - add more resources and run more service instances if required.
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27. Server Scalability
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28. Scale out – add a worker node running some or all of the services.
Server Scalability
Primary Node
Worker Node
Active
Repository
Active Extract Host
Gateway
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Scale out – add a worker node running some or all of the services.
©2011 Tableau Software Inc. All rights reserved.

29. Server Scalability
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30. Scale out – add a worker node running some or all of the services.
Server Scalability
Primary Node
Worker Node
Active
Repository
Active Extract Host
Gateway
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Standby
Repository
Standby Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Scale out – add a worker node running some or all of the services.
©2011 Tableau Software Inc. All rights reserved.

31. If the extract host or the repository fail…
Server Scalability
Primary Node
Worker Node
Failed
Repository
Failed Extract Host
Gateway
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Standby
Repository
Standby Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
If the extract host or the repository fail…
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32. … the standby will take over as the active.
Server Scalability
Primary Node
Worker Node
Failed
Repository
Failed Extract Host
Gateway
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Active
Repository
Active Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
… the standby will take over as the active.
©2011 Tableau Software Inc. All rights reserved.

33. When the failure is repaired, it starts up in standby mode.
Server Scalability
Primary Node
Worker Node
Standby
Repository
Standby Extract Host
Gateway
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Active
Repository
Active Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
When the failure is repaired, it starts up in standby mode.
©2011 Tableau Software Inc. All rights reserved.

34. Server Scalability
Primary Node
Worker Node
Standby
Repository
Standby Extract Host
Gateway
Application Server
VizQL Server
Data Server
Web Server 2
Active
Repository
Active Extract Host
Application Server
VizQL Server
Data Server
Web Server 2
Backgrounder
Web Server ↑
Worker Node
Worker nodes don’t need all the services – e.g. handling lots of extract refreshes…
©2011 Tableau Software Inc. All rights reserved.

35. Server Scalability
Primary Node
Worker Node
Worker Node
Gateway
Web Server
Standby
Repository
Standby Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Active
Repository
Active Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Separate the gateway and now our architecture starts to have HA properties…
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36. We can survive a total server failure of any worker node.
Server Scalability
Primary Node
Worker Node
Worker Node
Gateway
Web Server
Server
Down
Active
Repository
Active Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
We can survive a total server failure of any worker node.
©2011 Tableau Software Inc. All rights reserved.

37. For full HA, we require a failover gateway server.
Server Scalability
Primary Node
Worker Node
Worker Node
Active Gateway
Web Server
Standby
Repository
Standby Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Active
Repository
Active Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Failover Gateway
Web Server
For full HA, we require a failover gateway server.
©2011 Tableau Software Inc. All rights reserved.

38. In the event of a gateway failure…
Server Scalability
Worker Node
Worker Node
Server
Down
Standby
Repository
Standby Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Active
Repository
Active Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Failover Gateway
Web Server
In the event of a gateway failure…
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39. … we activate the failover gateway, but this is not automatic.
Server Scalability
Worker Node
Worker Node
Server
Down
Standby
Repository
Standby Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Active
Repository
Active Extract Host
Application Server
VizQL Server
Data Server
Backgrounder
Web Server 2
Active Gateway
Web Server
Primary Node
… we activate the failover gateway, but this is not automatic.
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40. ©2011 Tableau Software Inc. All rights reserved.
Caching
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41. ©2011 Tableau Software Inc. All rights reserved.
Terminology
Performance – the speed with which a single process can be completed, assuming no contention for resources.
Caching – a transparent store of values that have been calculated so that future requests for the same data can be serviced more quickly.
©2011 Tableau Software Inc. All rights reserved.
©2011 Tableau Software Inc. All rights reserved.

42. ©2011 Tableau Software Inc. All rights reserved.
Caching
Dashboard
Gateway
1. Image Tile Cache
VizQL
Server
Data Source
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43. ©2011 Tableau Software Inc. All rights reserved.
Image Tile Cache
Dashboards are delivered to the client as a series of image “tiles” – these are assembled to show the complete dashboard.
We can use this cache if:
Same dashboard (duh!)
No per-user security
Same dashboard size
Handled by the gateway service, one per VizQL worker node
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44. ©2011 Tableau Software Inc. All rights reserved.
Image Tile Cache
There is one single, simple step you can take to maximise the reuse of image tiles…
Fixed size dashboards!
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©2011 Tableau Software Inc. All rights reserved.

45. If We Miss the Image Tile Cache…
Dashboard
Gateway
1. Tile Cache
VizQL
Server
2. Model Cache
Data Source
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46. ©2011 Tableau Software Inc. All rights reserved.
Model Cache
When re-rendering the dashboard we check to see if computations have already be done
calculated fields, table calculations, reference lines, trend lines, etc
We can use this cache if:
No change to data
No change to calcs
Model cache is RAM based per VizQL server instance
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©2011 Tableau Software Inc. All rights reserved.

47. If We Miss the Model Cache…
Dashboard
Gateway
1. Tile Cache
VizQL
Server
2. Model Cache
3. Query Result Cache
Data Source
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Query Result Cache
The query result cache holds the results from queries we have sent to data sources
We can use this cache if:
Dimensions and measures are the same
Filters are the same – this means no per user security
Cache has not expired or is not explicitly bypassed
Query result cache is RAM based per VizQL server instance
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Managing Caching
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Managing Caching
Model cache
vizqlserver.modelcachesize:30
The number of models to cache, where there is one model per viz instance in a workbook
Query result cache
vizqlserver.querycachesize:64
The size in megabytes of query results to cache
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51. ©2011 Tableau Software Inc. All rights reserved.
Managing Caching
Distributing components is a scalability strategy, not a performance strategy
Caching is per-process
Distribution can hurt performance due to missing the cache
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©2011 Tableau Software Inc. All rights reserved.

52. ©2011 Tableau Software Inc. All rights reserved.
One Last Layer…
Dashboard
Gateway
1. Tile Cache
VizQL
Server
2. Model Cache
Data Extract
3. Query Result Cache
Data Source
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Extracts
Also can be used as a form of cache to improve user response times
Using aggregated extracts can improve performance even further (at the sacrifice of granularity)
Can be scheduled to refresh fully or incrementally
Using the Data Server they can be shared across multiple workbooks
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©2011 Tableau Software Inc. All rights reserved.

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Extracts
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55. ©2011 Tableau Software Inc. All rights reserved.
Summary
Tableau Server provides a flexible, scalable architecture that (in general) can look after itself.
Growing a Tableau Server installation to support more users and data is simple and does not require deep technical skills.
By understanding how Tableau Server’s caching mechanisms work, we can design our dashboards for optimal performance.
Unless you have a reason not to, make all dashboards fixed size.
©2011 Tableau Software Inc. All rights reserved.
©2011 Tableau Software Inc. All rights reserved.

56. ©2011 Tableau Software Inc. All rights reserved.
Q&A
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