Practicing at the Cutting Edge Learning and Unlearning about Performance. Martin Thompson

Transcription

1 Practicing at the Cutting Edge Learning and Unlearning about Performance Martin Thompson

2 Learning and Unlearning

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

4 1. Brief History of Java

5 Java Timeline In the beginning Java was Oak and Oak was slow

6 How did it all start?

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11 How did Java perform then?

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13

14 ...but everything must have a beginning

15 Java Timeline Netscape Navigator 2.0 & IE 3.0 with Applet support

16 Ma, I don t need to worry about deleting objects any more...

17

18

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

20 We could even do multi-threaded apps on Windows 3.11

21 Java Timeline Symantec and Microsoft JIT Performance Wars

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23 Life with early JIT Compilers

24 ...cross platform GUIs are a real possibility

25 Java Timeline Generational Garbage Collection Servlets

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27

28

29 But then came the surprise win

30 Servlets vs CGI

31 Graph Theory!

32 Java Timeline Hotspot Compiler JRockit for x86

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34 EJB

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36 Java Timeline Native Threads on Linux + epoll NIO

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39 Java Memory Model

40 Java Timeline Java Util Concurrent + JMM Class Data Sharing

41 Herb decided to write an essay...

42 The free lunch is over...

43 Java finds its way into our poor little mobile phones

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46 What about life on the Server?

47 EJB

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49 EJB

50 Java Timeline Escape Analysis Register Allocation Split Bytecode Verification

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

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58 SQL too difficult?

59 The world of hardware undergoes big changes!

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61 High Frequency Trading

62 Milliseconds Matter...

63 ...Microseconds Matter...

64 ...right from market open...

65 ...and especially after a quiet period...

66 ...it is like being at War

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69 Memory Cliff

70 SHM, Locks, and Multi-core

71 Safepoints!!!

72 Java Timeline Tiered Compilation G1 Garbage Collector Compressed Pointers

73 What does the near future hold?

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75 sun.misc.unsafe

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78 What is everyone excited about?

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80 What about other languages?

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82 Now on with the story...

83 2. Evolving Design Approach

84 GUI Era

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87 Battle for the Desktop

88 Battle for the Desktop

89 What was the biggest factor in performance?

90 People

91 Comms design is significant to GUIs

92 Users love responsive interfaces

93 Modelling

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95 Big Data Era

96 What do the following companies have in common?

97

98 Huge product catalogues

99 Logistics Partners Sales PCM Catalogues Websites Warehousing e-procurement Manufacturing

100 Parsing

101 Data Modelling & Representation

102 Indexing

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106 Set Theory Rocks!

107 Databases are very powerful!

108 Immutable Data Rocks!

109 JDBC Drivers Suck!!!

110 Stream Processing Rocks!

111 public void characters(char[] ch, int start, int length) throws SAXException

112 public void characters(char[] ch, int start, int length) throws SAXException public void startelement(string uri, String localname, String qname, Attributes atts) throws SAXException

113 public String[] split(string regex)

114 public String[] split(string regex) public Iterable<String> split(string regex)

115 public String[] split(string regex) public Iterable<String> split(string regex) public void split(string regex, Collection<String> dst)

116 Modelling

117 Design Paradigms OOP Set Theory

118 Transaction Processing Era

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120 Synchronous designs are seriously limited

121 Staged Event Driven Architecture

122 The importance of Latency

123 Latency Latency given Throughput Load

124 The issues with Concurrency

125 The Disruptor

126 The value of Determinism

127 The value of pure Functions

128 Modelling

129 Design Paradigms OOP Set Theory FP

130 3. Evolving Hardware Platform

131 Mechanical Sympathy

132 All Storage is Tape

133 Networks are faster than Storage

134 Memory Access Patterns Matter

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

136 Buckets

137 Buckets A1 Bob Key Value Hash Next

138 Buckets A1 Bob Key Value Hash Next Key Value Hash Next FF Jim

139 Buckets A1 Bob C7 Key Value Hash Next Fred Key Value Hash Next Key Value Hash Next FF Jim

140 Buckets Key Value Hash Next

141 Buckets Key Value Hash Next A1 Bob 4-1 0

142 Buckets Key Value Hash Next A1 Bob 4-1 C7 Fred

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

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

145 Value Types (Arrays ) ObjectLayout PackedObjects

146 Functional Programming will solve the multi-core problem - Functional Fanboi

147 Persistent Data Structures

148 HAMT Ref * Market HAMT * Venue HAMT * Instrument HAMT * Order

149 HAMT * Market HAMT << CAS Failure? >> Ref * Venue HAMT * Instrument HAMT * Order

150 Model Depth HAMT * Market HAMT << CAS Failure? >> Ref * Venue HAMT Threads * Instrument HAMT * Order

151 Shared Nothing to Scale Think Transputers but with message passing via SHM

152 4. Changes in Culture

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154 Measure Everything

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157 Questions? Blog: 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