Talk given during Devoxx Belgium 2016 https://cfp.devoxx.be/2016/speaker/anthony_dahanne Caching 101 Caching on the JVM Clustered Caching with Terracotta Server Deployment examples

1. © 2016 Software AG. All rights reserved. For internal use only
TERRACOTTA EHCACHE:
SIMPLER, FASTER, DISTRIBUTED
DEVOXX BELGIUM NOVEMBER 9TH 2016
ANTHONY DAHANNE
@ANTHONYDAHANNE

2. „Anthony Dahanne, Software Engineer @ Terracotta,
a Software AG company
„Working on the Terracotta Management Console,
and its integration in Terracotta products
„And strong Docker supporter :-P , trying to
containerize as much as I can !
LET ME INTRODUCE MYSELF
„Come visit us at Booth #1 ! Oculus Rift to win !!!

3. AGENDA
Caching 101
Caching on the JVM
Clustered Caching with Terracotta Server
Deployment examples

4. CACHING 101

5. CACHE DEFINITION
“Store of things
that will be required in the future,
and can be retrieved rapidly.”
from wiktionary.com
A Map (key / value mappings)
with capacity control (via eviction)
and freshness control (via expiry)

6. WHERE IS CACHING USED ?
from ArsTechnica

7. LATENCIES TO REMEMBER
L1 cache reference 0.5 ns
L2 cache reference 7 ns 14x L1 cache
Main memory reference 100 ns 20x L2 cache
Read 1 MB sequentially from memory 250,000 ns 250 us
Round trip within same datacenter 500,000 ns 500 us
Read 1 MB sequentially from SSD* 1,000,000 ns 1,000 us 1 ms ~1GB/sec SSD
Read 1 MB sequentially from disk 20,000,000 ns 20,000 us 20 ms 80x memory
Send packet CA->Netherlands->CA 150 ms 150 ms
from github.com/jboner

8. WHERE IS CACHING USED ?
Browser Caching CDN Caching
CPU Caching
Application Caching
Disk Caching

9. CACHING THEORY : AMDAHL’S LAW
“the theoretical speedup is always limited by the part of the task that cannot
benefit from the improvement.”, from Wikipedia
s : speedup in latency
p : percentage of the execution time

10. CACHING THEORY : THE LONG TAIL

11. CACHING GLOSSARY
• Hit : when the cache returns a value
• Miss : when the cache does not have a value
• Cold / Hot : when the cache is empty / full

12. WHAT TO MEASURE WHEN CACHING
• Cache Usage (empty ? full ?)
• HitRatio : hits / (misses + hits)
• HitRate : hits / second

13. CACHING ON THE JVM

14. HISTORY OF CACHING ON THE JVM
Review Ballot
2001
Public Review
2013
First Release
2003
2.0 “Express”
2010
2.3 Offheap
2011
JSR-107
EHCACHE
First Release
2003
Terracotta 5
2016
TERRACOTTA
Ehcache3
2016
2009
Ehcache acquisition
Public Release
2014

15. EHCACHE REBOOT : EHCACHE3
• 3.0 (May 2016)
• Compatible with JSR 107 (javax.cache)
• User managed cache
• Copiers & Serializers
• Strong typing
• 3.1 (Jun 2016)
• Clustered tier added
• 3.2 (2 days ago)
• High Availability with Terracotta Server

16. CACHING PATTERNS
• No Caching
• Cache aside
• Cache through
• Demo !
Business logic
Cache
GET(K)
PUT(K,V)
NULL
LOAD(K)
V
SoR
K,V
K,V
Business logic Cache
GET(K) LOAD(K)
V
PUT(K,V)
K,V
SoR
K,VV

17. CLUSTERED CACHING
WITH TERRACOTTA SERVER

18. TERRACOTTA SERVER RESOURCES
from ehcache.org documentation

19. MULTI CONTAINER DEPLOYMENT
PostgreSQL
Terracotta Server
Webapp with
Ehcache3 Clustered
Webapp with
Ehcache3 Clustered
Webapp with
Ehcache3 Clustered

20. DEPLOYMENT EXAMPLES

21. App
Server
App Server
App Server
DEPLOYMENT
App Server
App Server
Ehcache
App Server
JBOSS
SOA-P
App Server
Ehcache
Layer 7
“Presentation Zone” “Application Zone”
Individual
& Families
Issuers
3rd Parties
(B2B)
187K simultaneous users / 6K processes requests/s
10’s of Terracotta Servers / 100’s of caching clients

22. LINKS AND REFERENCES
• The essence of caching, by Greg Luck (available on youtube)
• Caching 101: Caching on the JVM (and beyond) by Louis Jacomet & Aurelien Broszniowski (available on
youtube)
• Ehcache3 documentation (available on ehcache.org)
• Ehcache3 and Terracotta Server demos (available on github)

23. © 2016 Software AG. All rights reserved. For internal use only23