第二章 Ergonomics Ergonomics is the process by which the Java Virtual Machine (JVM) and garbage collection tuning, such as behavior-based tuning, improve application performance. The JVM provides platform-dependent default selections for the garbage col…

第三章 Generations One strength of the Java SE platform is that it shields the developer from the complexity of memory allocation and garbage collection. However, when garbage collection is the principal bottleneck, it is useful to understand some aspec…

第六章 并行GC The Parallel Collector The parallel collector (also referred to here as the throughput collector) is a generational collector similar to the serial collector; the primary difference is that multiple threads are used to speed up garbage colle…

第5章 Available GC The Java HotSpot VM includes three different types of collectors, each with different performance characteristics. Java虚拟机有三种不同类型的gc,他们有不同的特性. 顺序gc The serial collector uses a single thread to perform all garbage collection work, whi…

第七章 并发gc Java 8提供两种并发gc,CMS和G1 Concurrent Mark Sweep (CMS) Collector This collector is for applications that prefer shorter garbage collection pauses and can afford to share processor resources with the garbage collection. CMS GC适用于偏好尽可能短的gc时间(因为gc会造…

第九章 G1 GC The Garbage-First (G1) garbage collector is a server-style garbage collector, targeted for multiprocessor machines with large memories. It attempts to meet garbage collection (GC) pause time goals with high probability while achieving high…

三色算法,高效率垃圾回收,jvm调优 Garbage collector:垃圾回收器 What garbage? 没有任何引用指向它的对象 JVM GC回收算法: 引用计数法(ReferenceCounting) 给对象中添加一个引用计数器,每当有一个地方引用他时,计数器值就+1,:当引用失效时,计数器值就-1:任何时刻计数器为0的对象就是不可能在被使 优点:判定效率高 缺点:不会完全准确,因为如果出现两个对象相互引用的问题就不行了 很明显,到最后两个实例都不再用了(都等于null了),但是GC…

原文转载自美团从实际案例聊聊Java应用的GC优化,感谢原作者的贡献 当Java程序性能达不到既定目标,且其他优化手段都已经穷尽时,通常需要调整垃圾回收器来进一步提高性能,称为GC优化.但GC算法复杂,影响GC性能的参数众多,且参数调整又依赖于应用各自的特点,这些因素很大程度上增加了GC优化的难度. 即便如此,GC调优也不是无章可循,仍然有一些通用的思考方法.本篇会介绍这些通用的GC优化策略和相关实践案例,主要包括如下内容: 优化前准备: 简单回顾JVM相关知识.介绍GC优化的一些通用策略.优化…

collector种类 GC在 HotSpot VM 5.0里有四种: incremental (sometimes called train) low pause collector已被废弃,不在介绍. 类别 serial collector parallel collector( throughput collector ) concurrent collector(concurrent low pause collector) 介绍 单线程收集器使用单线程去完成所有的gc工作,没有线程间的…

原文地址:http://www.cnblogs.com/redcreen/archive/2011/05/04/2037029.html collector种类 GC在 HotSpot VM 5.0里有四种: incremental (sometimes called train) low pause collector已被废弃,不在介绍. 类别 serial collector parallel collector( throughput collector ) concurrent coll…