Video and slides synchronized, mp3 and slide download available at URL http://bit.ly/1dImvww. Martin Thompson overviews Java's evolution, comparing it with C++'s, discussing the challenges of pushing the performance limits. Filmed at qconsf.com. Martin Thompson is a high-performance and low-latency specialist, with experience gained over two decades working on large scale transactional and big-data systems.

1. Practicing at the Cutting Edge
Learning and Unlearning
about Java Performance
Martin Thompson - @mjpt777

2. Watch the video with slide
synchronization on InfoQ.com!
http://www.infoq.com/presentations
/java-evolution-performance
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4. Java Performance

5. Learning and
Unlearning

6. 1. Brief History of Java
2. Evolving Design approach
3. An evolving Hardware platform
4. Changes in Culture

7. 1.
Brief History of Java

8. Java Timeline
1.0 1.1
96
97
1.2
98
99
1.3
00
1.4
01
02
5
03
04
05
6
06
07
7
08
09
10
11
In the beginning Java was Oak
and Oak was slow
12
13

9. How did it all start?

14. How did Java perform then?

18. ...but everything must have a
beginning

19. Java Timeline
1.0 1.1
96
97
1.2
98
99
1.3
00
1.4
01
02
5
03
04
05
6
06
07
7
08
09
10
11
12
Netscape Navigator 2.0 & IE 3.0
with Applet support
13

20. Ma, I don’t need to worry about
deleting objects any more...

23. ...but we can distribute rich GUIs
without an installer

24. We could even do multi-threaded
apps on Windows 3.11

25. Java Timeline
1.0 1.1
96
97
1.2
98
99
1.3
00
1.4
01
02
5
03
04
05
6
06
07
7
08
09
10
Symantec and Microsoft
JIT Performance Wars
11
12
13

27. Life with early JIT Compilers

28. Sun vs Microsoft – Round One

29. ...cross platform GUIs are
a real possibility

30. Java Timeline
1.0 1.1
96
97
1.2
98
99
1.3
00
1.4
01
02
5
03
04
05
6
06
07
7
08
09
10
11
12
Generational Garbage Collection
Servlets
13

32. Jalapeño
Processor

34. But then came the surprise win

35. Servlets vs CGI

37. Graph Theory

38. Java Timeline
1.0 1.1
96
97
1.2
98
99
1.3
00
1.4
01
02
5
03
04
05
6
06
07
7
08
Hotspot Compiler
JRockit for x86
09
10
11
12
13

40. EJB

42. Sun vs Microsoft – Round Two

43. Java Timeline
1.0 1.1
96
97
1.2
98
99
1.3
00
1.4
01
02
5
03
04
05
6
06
07
7
08
09
10
11
12
Native Threads on Linux + epoll
NIO
13

46. Java Memory Model

47. Sun vs Microsoft – Round Two

48. How did that go?

49. $1.6 Billion Settlement!

51. Java Timeline
1.0 1.1
96
97
1.2
98
99
1.3
00
1.4
01
02
5
03
04
05
6
06
07
7
08
09
10
11
Java Util Concurrent + JMM
Class Data Sharing
12
13

52. Herb decided to write an essay...

53. The free lunch
is over...

54. Java finds its way into our poor
little mobile phones

56. Déjâ vue?

58. What about life on the Server?

59. EJB

61. EJB

62. Java Timeline
1.0 1.1
96
97
1.2
98
99
1.3
00
1.4
01
02
5
03
04
05
6
06
07
7
08
09
10
11
Escape Analysis
Register Allocation
Split Bytecode Verification
12
13

67. How did that go?

69. What about our hero who freed us
from the EJB tar pit?

74. SQL too difficult?

75. The world of hardware
undergoes big changes!

77. High Frequency Trading

78. Milliseconds Matter...

79. ...Microseconds
Matter...

80. ...right from market
open...

81. ...and especially after a
quiet period...

82. ...it is like being at War

84. Memory Cliff

85. Locks and Multi-core

86. Safepoints!!!

87. Java Timeline
1.0 1.1
96
97
1.2
98
99
1.3
00
1.4
01
02
5
03
04
05
6
06
07
7
08
09
Tiered Compilation
G1 Garbage Collector
Compressed Pointers
10
11
12
13

88. What does the future hold?

92. What is everyone excited about?

94. Does our new leader care?

97. The present day

98. 2.
Evolving Design Approach

99. GUI Era

102. Battle for the Desktop

103. Battle for the Desktop

104. What was the biggest
factor in performance?

105. People

106. Reactive Designs Scale Well

107. Comms are significant to GUIs

108. Users love responsive interfaces

109. Modelling

111. “Big” Data Era

113. What do the following
companies have in common?

115. Huge product catalogues

116. Partners
Logistics
Catalogues
Sales
PCM
Warehousing
Manufacturing
Websites
e-Procurement

117. Data

118. Parsing

122. Stream Processing Rocks!

123. public void startElement(String uri,
String localName,
String qName,
Attributes atts)
throws SAXException

124. public void startElement(String uri,
String localName,
String qName,
Attributes atts)
throws SAXException
public void characters(char[] ch,
int start,
int length)
throws SAXException

125. public String[] split(String regex)

126. public String[] split(String regex)
public Iterable<String> split(String regex)

127. public String[] split(String regex)
public Iterable<String> split(String regex)
public void split(String regex,
Collection<String> dst)

128. Set Theory Rocks!

129. Databases are very powerful!

130. Immutable Data Rocks!

131. Batching Rocks!

132. JDBC Drivers Suck!!!

133. Modelling

134. Design Paradigms
Different
Same
Different

135. Transaction
Processing
Era

137. Staged Event Driven Architecture

138. Synchronous Designs are Limited

139. The importance of Latency

140. Latency
Latency given Throughput
Load

141. The issues with Concurrency

142. The Disruptor

143. The value of Determinism

144. The value of pure Functions

145. Modelling

146. Design Paradigms
Different
Different
Same
Different

147. 3.
Evolving Hardware
Platform

148. All Storage is Tape

149. Networks are faster than
Storage

150. Memory Access Patterns Matter

151. What if you could build a HashMap
with reified generics
and arrays of structures?

152. Buckets

153. Bob
Buckets
A1
Key
Value Hash Next

154. Bob
Buckets
A1
Key
Value Hash Next
Key
Value Hash Next
FF
Jim

155. Bob
Buckets
A1
C7
Fred
Key
Value Hash Next
Key
Key
Value Hash Next
FF
Jim
Value Hash Next

156. Buckets
Key
Value
Hash
Next

157. Buckets
Value
Hash
Next
A1
0
Key
Bob
4
-1

158. Buckets
Hash
Next
Bob
4
-1
C7
0
Value
A1
1
Key
Fred
2
-1

159. Buckets
Hash
Next
Bob
4
2
C7
0
Value
A1
1
Key
Fred
2
-1
FF
Jim
4
-1

160. .Net Dictionary is 10X faster
than HashMap for 2GB of data

161. Concurrent Garbage Collection?

162. Safepoints!!!

163. Shared Nothing to Scale
Think Transputers
but with
messaging
passing via SHM

164. 4.
Changes in Culture

166. Measure Everything

168. Continuous Profiling

169. Mechanical Sympathy

170. Discoveries from Load Testing
Most generators
are very limited

171. Discoveries from Load Testing
Libs and
Frameworks could
be much better

172. What have I learned that is
really important?

173. Research

174. Experiment

175. Collaborate

176. Questions?
Blog: http://mechanical-sympathy.blogspot.com/
Twitter: @mjpt777
“It does not matter how intelligent you are,
if you guess and that guess cannot be backed
up by experimental evidence then it is still a guess.”
- Richard Feynman

177. Watch the video with slide synchronization on
InfoQ.com!
http://www.infoq.com/presentations/javaevolution-performance