The document discusses the use of JSR-107 (JCache) to enhance application performance through caching techniques. It outlines the basics of caching, when to implement it, and various JCache implementations available for Java applications. Additionally, it provides insights on integrating caching with popular frameworks and managing cache lifecycles and statistics.

1. Using JCache to
speed up your apps
Vassilis Bekiaris
Software Engineer, Hazelcast
@karbonized1

2. About me
• First computer:
Amstrad 6128 green screen
• Favorite languages I never
used in production: Ada, CLISP
• Freelancer (-2008)
• Software Architect, Team Leader, Jack of all Trades
(2008-2016)
• Software Engineer, Hazelcast (2016-)

3. Outline
• Caching basics
• Introducing JSR-107 (JCache)
• Using JCache

4. Why cache?
• Performance
• Offload expensive or non-scalable parts of your
architecture
• Buffer against load variability
• Usually fast and easy to apply

5. When to use caching
• When applications use the same data more than
once
• When fetching or producing the data again is
expensive

6. Caches in RAM and beyond
NVRAM/Flash/SSD
(serialized form)
Local Storage
Heap
(Objects)
Opaque to
GC in RAM
(serialized form)
<100 ns
< 100ns
+deserialization time
2
500
1,000+
Latency
Size (GB)
Network Storage
< 50us
+deserialization time
< 140us for 1Gbps
< 70us for 10Gbps/40Gbps
+deserialization time
20,000+Scaleout across the network
(serialized form)
Diagram: Greg Luck

7. Implementation patterns
• Cache aside
App Cache
System
of
Record
(1) get
(2) null
(3) fetch (4) value
(5) put

8. Implementation patterns
• Cache through
App Cache
System
of
Record
(1) get
(2) fetch
(3) value
(4) value

9. Other implementation
considerations
• In-process
• Distributed

10. Introducing JSR-107
• The standard way to cache for Java applications
• One of the longest running JSRs
• Started in 2001
• JSR-107 1.0 final released in March 2014
• JSR-107 1.1 maintenance release (draft review
done, expected mid-December 2017)
• Target: Java SE 6+

11. JCache implementations
• Apache Ignite
• Blazing Cache
• cache2k
• Caffeine
• Coherence (Oracle)
• Ehcache
• Hazelcast
• Infinispan
• …
(https://jcp.org/aboutJava/communityprocess/implementations/jsr107/index.html)

12. java.util.Map
Key-Value Based API
Supports Atomic Updates
Entries Don’t Expire
Entries Aren’t Evicted
Entries Stored On-Heap
Store-By-Reference
javax.cache.Cache
Key-Value Based API
Supports Atomic Updates
Entries May Expire
Entries May Be Evicted
Entries Stored Anywhere (ie: topologies)
Store-By-Value and Store-By-Reference
Supports Integration (ie: Loaders / Writers)
Supports Observation (ie: Listeners)
Entry Processors
Statistics
Cache != Map

13. Cache now!
• Add javax.cache:cache-api:1.0.0 to your classpath
• Add an implementation
• Hello, world!

14. JCache API
• Caching
• “Service loader”: locates implementation, supplies CachingProvider(s)
• CachingProvider
• Creates & manages CacheManagers (per {URI, ClassLoader})
• CacheManager
• Manages Caches lifecycle
• Cache
• That’s what your app uses!

15. Entry processors
• Data transformations
• Computations

16. Listeners
• Caches are observable
• CacheEntryCreatedListener
• CacheEntryUpdatedListener
• CacheEntryRemovedListener
• CacheEntryExpiredListener

17. Cache Loader/Writer
• Integration with system of record
• Read-through, write-through

18. Annotations
• @CacheResult
@CachePut
@CacheRemove
@CacheRemoveAll
• JSR107 RI provides support for CDI, Spring &
Guice

19. Annotations
@CacheDefaults(cacheName = “users”)
class User {
@CacheResult
User getUser(long id);
@CachePut
void createUser(long id, @CacheValue User user);
@CacheRemove
User removeUser(long id);
…
}

20. Management & Statistics
• Via JMX
• Can be enabled/disabled at runtime
• CacheManager.enableStatistics(cacheName, true)
• CacheManager.enableManagement(cacheName, true)

21. Integrations
• Spring
• CDI
• Payara server

22. JSR-107 links
• JCP Project:
• http://jcp.org/en/jsr/detail?id=107
• Source Code:
• https://github.com/jsr107
• Forum:
• https://groups.google.com/forum/?fromgroups#!
forum/jsr107

23. Sample code
• Sample project
• https://github.com/vbekiaris/jcache-demo
• Adding caching with JSR107 annotations to a
spring-boot sample:
• https://github.com/vbekiaris/spring-boot/tree/
jcache-jhug/add-caching-to-echoservice