Using JCache to speed up your apps
- 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