Java Performance

Basics and performance measurements

• Performance dimensions
• The process of creating efficient software
• Factors affecting performance
• Micro and Macro-Benchmarking
• Profiling
• Use of tools: JConsole, Java Visual VM, JMC (Java Mission Control), MAT (memory analysis)

• IO: streams, buffering, RandomAccessFile
• NIO: channels, memory mapped files
• NIO.2 (introduction): Path, Files
• How to increase serialization performance

• Computational complexity - how to choose algorithms
• Recursion, iteration and heuristics
• Performance for sets, lists, queues, maps
• Views and Collections class
• Review of multithreaded collections (java.util.concurrent)
• Arrays and collections for simple types

• Creating JMH project and benchmarks
• Configuration, running, results
• Concurrent and parameterizable Benchmarks
• Traps and advanced elements

• Class Class, ClassLoader and class loading process
• When to control class loading?
• Delaying class loading and reducing the number of classes
• Reflection and dynamic proxy
• Introduction to modules (Java 9)

• Garbage Collector and object life cycle
• Strong, soft, weak and phantom references
• Why memory leak occurs and what to avoid in Java
• Generations and memory spaces
• Tuning Garbage Collector
• Types of Garbage Collector: Serial, Parallel, Concurrent, G1
• Changes in Java 8 and Java 9

• Client and server modes
• Tuning JVM
• Performance changes from version to version

• Problems with server side optimization
• Testing with HTTP: HttpUnit, JWebUnit, Selenium
• Performance measurements for HTTP: Grinder, JMeter
• Additional information about JMeter

• Micro-benchmarking problems
• Premature optimization
• Greed
• Other bad practices