The document provides an introduction and overview of design patterns. It defines design patterns as common solutions to recurring problems in software design. The document discusses the origin of design patterns in architecture, describes the four essential parts of a design pattern (name, problem, solution, consequences), and categorizes patterns into creational, structural, and behavioral types. Examples of commonly used patterns like Singleton and State patterns are also presented.
This document discusses task-based programming models for distributed computing. It defines tasks as distinct units of code that can be executed remotely. Task computing provides distribution by harnessing multiple computing nodes, unlike multithreaded computing within a single machine. The document categorizes task computing into high-performance, high-throughput, and many-task computing. It also describes popular task computing frameworks like Aneka, Condor, Globus Toolkit, and describes developing applications using the Aneka task programming model.
This document discusses memory-efficient Java programming practices, highlighting the importance of understanding Java memory usage, object allocation, and collection types. It outlines different Java collection implementations, their overhead, and the implications of using 32-bit versus 64-bit JVMs on memory efficiency. Additionally, it emphasizes the need for careful management of temporary objects and collection capacities to optimize performance and reduce memory footprint.
The document provides an overview of architectural patterns in system design, highlighting their importance in determining technology, module interactions, and overall architecture. Key patterns discussed include pipe and filter, layers, shared-data, client-server, publish-subscribe, peer-to-peer, call and return, and blackboard, each with specific use cases and characteristics. Architectural patterns serve as reusable solutions that can significantly influence the performance and scalability of systems.
The document discusses various design patterns. It begins by explaining that design patterns represent best practices used by experienced software developers to solve common problems. It then discusses the Gang of Four (GOF) patterns, which were identified in 1994 and include creational, structural, and behavioral patterns. Creational patterns like Singleton, Factory Method, Abstract Factory, and Prototype are covered. Structural patterns like Adapter, Bridge, Composite, Decorator, Facade, Flyweight, and Proxy are also introduced. Behavioral patterns like Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observer, State, Strategy, Template Method, and Visitor are briefly mentioned as well. The document then discusses some Java Enterprise
This document discusses software project management artifacts. Artifacts are organized into management and engineering sets. The management set includes artifacts like the work breakdown structure, business case, and software development plan. The engineering set includes requirement, design, implementation, and deployment artifact sets. Each set captures information through various notations and tools to manage the software development lifecycle.
The document introduces software design patterns as reusable solutions for common problems in software design, categorized into structural, creational, and behavioral patterns. Each category includes various methods that address specific interactions and functionalities between classes and objects. An example illustrates the use of the factory method from the creational patterns, demonstrating how to implement and manage different user galleries efficiently.
1. The document discusses RESTful APIs and gRPC, comparing their characteristics and use cases.
2. RESTful APIs typically use HTTP and JSON to access resources via URLs while gRPC uses protocol buffers and HTTP/2 for efficient streaming and RPC.
3. gRPC is better suited for microservices and mobile apps due to its ability to handle streaming and performance, while REST is more widely used due to its simplicity and support in most languages.
1. The document discusses RESTful APIs and gRPC, comparing their characteristics and use cases.
2. RESTful APIs typically use HTTP and JSON to access resources via URLs while gRPC uses protocol buffers and HTTP/2 for efficient streaming and RPC.
3. gRPC is better suited for microservices and mobile apps due to its ability to handle streaming and performance, while REST is more widely used due to its simplicity and support in most languages.
JavaOne 2016 Java SE Feedback #jjug #j1jpYuji Kubota
?
狠狠撸 for reporting Java SE Feedback of JavaOne 2016 at Japan Java User Group. Especially, this slide introduces the changes required for Java 9.
https://jjug.doorkeeper.jp/events/52639
- The document discusses optimizing Java performance on hardware by leveraging features like AES-NI, transparent huge pages, and compiler intrinsics.
- It provides examples showing performance improvements from using these features, such as faster encryption times when enabling AES-NI and fewer TLB misses with transparent huge pages.
- It also discusses Java VM options, garbage collection, and the HotSpot compiler related to hardware optimization.
Protect Your IoT Data with UbiBot's Private Platform.pptxユビボット 株式会社
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Our on-premise IoT platform offers a secure and scalable solution for businesses, with features such as real-time monitoring, customizable alerts and open API support, and can be deployed on your own servers to ensure complete data privacy and control.
![実証コード
import java.nio.file.*;
import java.util.jar.*;
public class MetaFlood{
public static void main(String[] args) throws Exception{
Path rtjar_path = FileSystems.getDefault().getPath(
System.getProperty("java.home"), "lib", "rt.jar");
try(JarFile rtjar = new JarFile(rtjar_path.toFile())){
rtjar.stream().filter(e -> !e.isDirectory())
.map(e -> e.getName())
.filter(n -> n.endsWith(".class"))
.map(n -> n.substring(0, n.length() - 6).replace('/', '.'))
.forEach(n -> { System.out.println(n);
try{
ClassLoader.getSystemClassLoader().loadClass(n);
}
catch(ClassNotFoundException ex){}
catch(OutOfMemoryError oome){
System.out.println(oome.toString());
throw oome;
}
});
}
}
}](https://image.slidesharecdn.com/metaspace-140518094955-phpapp02/85/Metaspace-23-320.jpg)
![GCログの例
[Full GC (Metadata GC Threshold)
[PSYoungGen: 496K->0K(2560K)]
[ParOldGen: 388K->836K(6656K)] 884K->836K(9216K),
[Metaspace: 7292K->7292K(9216K)], 0.0123187 secs]
[Times: user=0.02 sys=0.00, real=0.01 secs]
[Full GC (Last ditch collection)
[PSYoungGen: 0K->0K(2560K)]
[ParOldGen: 836K->792K(6656K)] 836K->792K(9216K),
[Metaspace: 7292K->7292K(9216K)], 0.0134180 secs]
[Times: user=0.04 sys=0.00, real=0.02 secs]
※見やすく改行しています
Metaspaceが
足りなくて
GCが発生
GCしても
まだ足りないため
最後の悪あがき](https://image.slidesharecdn.com/metaspace-140518094955-phpapp02/85/Metaspace-29-320.jpg)
![GCログ
? PermだったところがMetaspaceに変わって
います
$ /usr/local/jdk1.8.0_05/bin/java -XX:+PrintGCDetails SystemGC
：
[Full GC (System.gc())
[PSYoungGen: 368K->0K(1024K)]
[ParOldGen: 8K->251K(59904K)]
376K->251K(60928K),
[Metaspace: 2377K->2377K(1056768K)], 0.0047055 secs]
[Times: user=0.01 sys=0.00, real=0.00 secs]
：
※見やすく改行しています](https://image.slidesharecdn.com/metaspace-140518094955-phpapp02/85/Metaspace-38-320.jpg)
![Native Memory Tracking (NMT)
? 細かい情報を簡単に知りたいときに最適
? -XX:NativeMemoryTracking=[summary|detail]
? 取り方は2種類
? -XX:+UnlockDiagnosticVMOptions と
-XX:+PrintNMTStatistics でjava終了時に取得
? jcmd <PID> VM.native_memoryで外側から取得
? Metaspaceは”Class”の部分です](https://image.slidesharecdn.com/metaspace-140518094955-phpapp02/85/Metaspace-39-320.jpg)
