1. MIS 324 -- Professor Sandvig MIS 424 Professor Sandvig
12/6/2018
Caching
MIS 424
Professor Sandvig

2. MIS 324 -- Professor Sandvig
12/6/2018
Overview
What is caching
Where to cache
When to cache
Data caching in .NET MVC
Create you own cache

3. MIS 324 -- Professor Sandvig
12/6/2018
What is Caching
Cache = “store”
Armies: cache weapons
Birds: cache nuts
Computers: cache data
Benefits of caching data:
Reuse
Process once, reuse many times
Faster, cheaper

4. Where to cache Browser Network Server Proxy Servers
Content Delivery Networks
Server

5. MIS 324 -- Professor Sandvig
12/6/2018
Where to Cache
Browser
Each resource may specify cache policy
Cache-control header
Reduces:
download times
Bandwidth usage
Example:
WWU
Chrome developer tools

6. MIS 324 -- Professor Sandvig
12/6/2018
Where to Cache
Network
Proxy Server

7. MIS 324 -- Professor Sandvig
12/6/2018
Where to Cache
Content Delivery Networks (CDNs)
Globally distributed network proxy servers

8. CDNs Amazon CloudFront Akamai video (2.51) 53 Edge Servers
Content delivered from closest to customer
Akamai video (2.51)

9. MIS 324 -- Professor Sandvig
12/6/2018
Where to Cache
All of the above
Nytimes.com
Browser caching
Content Delivery Network
Server
Blog on caching

10. MIS 324 -- Professor Sandvig
12/6/2018
When to Cache on server
Frequently hit pages
Content changes infrequently
NYTimes.com
ESPN.com
CMS (see Drupal Boost)
Data is expensive to retrieve
MIS 424
Weather forecast
Amazon Best Sellers

11. MIS 324 -- Professor Sandvig
12/6/2018
When NOT to cache
Pages that change frequently
Shopping cart
Facebook
Customized for each user
Infrequently accessed data
Cache must be stored  Overhead
cost depends upon caching method

12. MIS 324 -- Professor Sandvig
12/6/2018
Caching Tools in .NET
Caching Options
Output Cache Attribute
Cache class
Create your own
Database
Application or session object

13. Output Cache Attribute
Decorate ActionMethod:
[OutputCache(Duration=30, VaryByParam="none")]
public ActionResult Index()
Duration: seconds

14. VaryByParm Example: Keep caches for specific parameters
VaryByParm = “custID”
Different cache for each customer
VaryByParm = “*”
Different cache for all parms
Example:
VaryByParm=“custID” output

15. Cache Location Client – cached on browser Server – cached on server
ServerAndClient – *default
Any – browser & server & proxy servers
None – no caching

16. Cache Attribute Apply to controller Apply to partial views
Applies to all action methods in controller
Apply to partial views
Cache only partial view
Example: MVC Music

17. MIS 324 -- Professor Sandvig
12/6/2018
.NET MVC Caching
Output Cache Attribute
Cache class
Create your own

18. MIS 324 -- Professor Sandvig
12/6/2018
Cache Class
Set expiration date
Several
Cache any type of data object
strings, List<>, array …
Cached data accessible throughout application
Use data on multiple page options

19. MIS 324 -- Professor Sandvig
12/6/2018
Cache Class
Cache.Insert method
Parameters for:
Expiration date – absolute & sliding
File dependencies
Database tables
Example:
CacheClass source, output

20. MIS 324 -- Professor Sandvig
12/6/2018
Create Your Own
Program own rules
Customize storage location
Database
File
Combination of cache locations
Expiration rule
Fixed time of day, week, month…
Idle duration
Example: Weather history
Storage: Sql server database
Delete after 180 days
PHP: cache to file

21. MIS 324 -- Professor Sandvig
12/6/2018
Summary
Caching widely used
Browser
Network caching
Server .NET options:
Cache attribute
Views and partial views
Cache Class
Roll your own