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JCache (JSR107)
David Brimley
The standard for Java Caching
Who is this guy?
Senior Solutions Architect @ Hazelcast
Java Developer for 17 years
@dbrimley
In Memory Data Grids for 8 years
Worked for Investment Banks
Started out coding Basic on a Commodore Vic-20
My fav computer was my old BBC Model B
Long suffering Spurs fan.
HSBC, Nomura, Credit Suisse, BZW, RBoS
Oracle Coherence 4 YearsPivotal Gemfire 4 Years
David Brimley
Runs HUGL (Hazelcast User Group London)
Low latency trading systems
What we’ll cover…• Why Caching? • Introduction to JCache. • Using Caches. • Entry Processors. • Listeners. • Annotations. • Missing Bits. • Questions.
Who uses caching?
Quick Show of hands
Why Caching?
Why Caching?The Speed Factor (Memory .v. Disk)
L1 cache reference 0.5 ns
Branch mispredict 5.0 ns
L2 cache reference 7.0 ns
Mutex lock/unlock 25.00 ns
Main memory reference 100.00 ns
Compress 1k bytes with ZupZ 3,000.00 ns
Send 1k bytes over 1Gpbs network 10,000.00 ns 0.01 ms
Read 4k randomly from SSD 150,000.00 ns 0.15 ms
Read 1 MB sequentially from memory 250,000.00 ns 0.25 ms
Round trip within same datacenter 500,000.00 ns 0.50 ms
Read 1 MB sequentially from SSD 1,000,000.00 ns 1.00 ms
Disk seek 10,000,000.00 ns 10.00 ms
Read 1 MB sequentially from disk 20,000,000.00 ns 20.00 ms
Send packet CA->Netherlands->CA 150,000,000.00 ns 150.00 ms
https://gist.github.com/jboner/2841832
Why Caching?
Graph of Memory Prices Decreasing with Time (1957-2014)
http://www.jcmit.com/mem2014.htm
The Cost Factor
Why Caching?Lots of Use Cases
Slow Database
HTTP Proxy
Browser
Persistence Framework
Disk
Application
Hard to scale Database
Lots of Cache Types
Local Cache Data Grid
Document Store JPA Second Level
JPA First Level
Introduction to JCache
Introduction to JCache• Caching for the Java Platform
• Produced via the JCP / JSR107
• Ratified March 2014
• 10 years in the making.
• Works with SDK.
• Spec Leads: Greg Luck, Brian Oliver
java.util.Map (Java 6/7)
Key-Value Based API
Supports Atomic Updates
Entries Don’t Expire
Entries Aren’t Evicted
Entries Stored On-Heap
Store-By-Reference
https://gist.github.com/jboner/2841832
Introduction to JCacheMap .v. Cache
javax.cache.Cache (Java 6)
Key-Value Based API
Supports Atomic Updates
Entries May Expire
Entries May Be Evicted
Entries Stored Anyware (ie: topologies)
Store-By-Value and Store-By-Reference
Supports Integration (ie: Loaders/Writers)
Supports Observation (ie: Listeners
Entry Processors
Statistics
JCache makes NO assumptions about
topology.
Single Process or Distributed
Introduction to JCache
Introduction to JCache
• 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
JSR107 TCK Compliant Vendors
Introduction to JCache
https://jcp.org/aboutJava/communityprocess/implementations/jsr107/index.html
I pity the fool that claims to support JCache without
TCK compliance
As of 5th March 2015
Introduction to JCacheSomething to remember when comparing vendors of distributed caches…
Do NOT Benchmark with a single instance!
Using Caches
Using Caches
<dependency> <groupId>javax.cache</groupId> <artifactId>cache-api</artifactId> <version>1.0.0</version> </dependency>
Maven Central
Using CachesClasses
Caching “service loader”
CachingProvider “SPI Implementation”
CacheManager “manager of caches”
Cache “interface to a Cache”
Using CachesClasses
Code Walkthrough
Entry Processors
Entry ProcessorsCompute in place
• Atomic Operations in situ of data.• Eliminate Round-Trips (if distributed)
• Lock Free• Needs Serialisation (if distributed)
Application Application
Cache Cache
Entry ProcessorsClasses
Code Walkthrough
Listeners
ListenersCallbacks for events in Cache
• Follows Observer Pattern
• Interface per event type
• Created, Updated, Removed, Expired
• Iterations of Events passed back
• MutableCacheEntryListenerConfiguration
ListenersClasses
Code Walkthrough
Cache Loaders / Writers
Cache Loaders / WriterCache Misses / Cache Persist
Application
Cache
Backing Store
Cache Loaders / WriterClasses
Code Walkthrough
Annotations
AnnotationsSpring 4.1, Guice, CDI
• @CacheResult
• @CachePut
• @CacheRemove
• @CacheRemoveAll
AnnotationsClasses
Code Walkthrough
Missing Bits
Missing BitsThe Future of JCache
• Async API
• Query
• JEE 8
• Servlet 4.0 (Session Cache)
• Java 8 Lang Features (Lambda/Streams)
Questions ?
HAZELCAST• Free London Training • Hazelcast User Group• Visit our Booth
Visit our Booth 5th Floor Get Free Training (Canary Wharf, Thursday 12th March) http://hazelcast.com/events/
Join the Hazelcast User Group London (HUGL) http://www.meetup.com/Hazelcast-User-Group-London-HUGL/
Download Hazelcast, the leading open source IMDG http://www.hazelcast.org
