sflow collector

Refer to http://www.oracle.com/technetwork/tutorials/tutorials-1876574.html for detail. Some of the content is copied here. The G1 garbage CollectorThe Garbage-first (G1) collector is a server-style garbage collector, targeted for multi-processor machines with large mem Ories. It meets Garbage collection (GC) Pause time goals with a high probability, while achieving high throughput. The G1 garbage

Chapter 5 JVM garbage collector (1): jvm garbage collection (The garbage collection algorithm is a theory, and the garbage collector is a collection algorithm. For details about the collection algorithm, see Chapter 4 JVM garbage collection algorithm.) 1. Seven garbage collectors Serial (Serial GC) ParNew (parallel GC) Parallel Scavenge (Parallel GC collection) Serial Old (MSC) (Serial GC) CMS (concur

is running can we know what objects will be created. The allocation and recycling of this part of memory are dynamic, and the garbage collector focuses on this part of memory, in the subsequent discussions in this book, "Memory" Allocation and recovery only refer to this part of memory. Reclaim Policy Recycling:　　　 The memory is released by clearing unused objects, and garbage collection is another important function.Eliminate heap memory space fr

Let's review the main Java garbage collector (HotSpot JVM). This article is discussed for garbage collection of heaps. The heap is decomposed into a smaller three-part. Specifically divided into: The new generation, the old age, lasting generations. Most of the newly generated objects are placed in the Eden area, and when the Eden area is full, the JVM will trigger the young GC for not having to request memory, and the Survivor area (set as

Bruce Eckel's first two chapters of Thinking in java have repeatedly stressed this point: memory leak in C ++ won't happen in java, developers do not need to consider this issue at all, which greatly reduces the development time. This is because java has a garbage collector that monitors all objects created with new, identifies objects that will not be referenced, and then releases the memory space of these objects, to be used by other new objects. Bu

Young generation CollectorSerial collectorThe serial collector uses the tag-copy garbage collection algorithm. The serial collector can only use one thread for garbage collection, and when garbage collection is done, all worker threads need to stop working, waiting for the garbage collection thread to finish before other threads can continue to work. In a single-core scenario, this

JAVA Garbage Collector Overview 1. Combination of garbage collectors There are a total of 7 JAVA garbage collectors, minus G1, which has not yet been officially used in a large scale. There are also 6, 3 in the new generation and 3 in the old generation. Because the garbage collector is a group of tasks, these six collectors constitute a total of 5 usage modes. Parameters Description -X

1. The object is dead?a, Reference Counting Algorithm: The disadvantage is that it is difficult to solve the problem of mutual circular reference between objects, the Java language does not choose it.b, root Search algorithm (GC Roots tracing): through a series of objects named "GC Roots" as the starting point, start down search, traversed by the path is called the reference chain, when an object does not have any reference chain connected, the surface of this object is Unreachable. In the Java

Ava Beginner Practice Tutorial 14-garbage collectorPeople who have used C + + programming know that they always have to keep track of the objects they create, and that they need to be shown to remove unwanted objects. This way is too troublesome, error prone. Write so much code, can remember, if the useful to delete how to do, if there is no use to forget how to do. These problems are very serious. The garbage collector used in the Java language manag

Any language that creates objects in the process of running it means that they need to allocate space in memory for these objects, and when those objects lose their meaning, they need to be freed up to make sure that the memory is available to the new object. The release of object memory is a garbage collection mechanism, also called a GC, for Java developers, GC is a double-edged sword. We've got two funny pictures here to show the C-language garbage collection and Java garbage collection. Note

that are accessible from the root node, then move all objects to one end, and then clear out the memory benefits beyond the bounds: no memory fragmentation Disadvantage: The object is moved on top of the tag, the cost is relatively high, The efficiency is also not high 4. Generational recovery algorithm 2. The new generation of collector serial single-threaded: simple and efficient parnew serial multi-threaded version, with the CMS, can not be combin

New Generation Collectors Serial Single thread will appear stop the world Compatible with CMS collectors Using the replication algorithm Parnew Serial version of Multithreading In addition to serial, only he can cooperate with the CMS collector Using the replication algorithm Paraller Scavenge Multithreading Collector Using the replication algorithm throughput priority garbage

1. The serial collector was once the only option for the new generation of virtual machines, a single-threaded collector that must stop the world when collecting garbage, which is the default Cenozoic collector that the virtual machine runs in client mode.2, Serial old is the older version of the Serial collector, is a

Garbage collector and memory allocation policyOne, GC Collector1. GC recycling three things to think about:A) How to determine which memory needs to be recycled?b) What recycling is used?c) when to recycle?The following is a description of each of these issues.Question 1: How can I tell what memory needs to be recycled?There are two methods of judging (hotspot defaults to the second type):1. Reference counting algorithmAdd a reference counter to the o

3.1 Overview What problems does the garbage collector solve? Which memory needs to be recycled When is it recycled? How to Recycle Reference counting algorithm:When there is a reference to a place, +1, the reference fails,-1. Disadvantage: The problem of circular referencing between objects.Accessibility Analysis algorithm:Idea: Through a series of objects that become "GC Roots" as starting points, starting from these nodes to ex

corresponding memory collation, but there is a "fragmentation" problem. Of course, the disadvantage of this algorithm is also very obvious, that is, twice times the memory space required.4. Mark-Finishing (mark-compact)This algorithm combines the advantages of "tag-clear" and "replicate" two algorithms. It is also divided into two phases, the first phase marks all referenced objects from the root node, the second phase traverses the entire heap, clears the unmarked objects and "compresses" the

Tags: collector jdbd Configuration Integration use methodThe collector JDBC is similar to an incomplete database JDBC driver, which does not have a physical table and can treat the collector as a database with only stored procedures (strong computational power, weak storage mechanism). very similar to using Database JDBC , you can call the

Clever use of PHP functions to implement collectors. PHP has been developing for a long time and many users are familiar with PHP. now we can use PHP functions to implement the collector program. What is a collector? it is usually called a thief program. it is mainly used to catch PHP. after a long period of development, many users know PHP very well. now we can use PHP functions to implement the

In this article, we will talk about the relationship between the garbage collector and the virtual memory and physical memory of the program. Let's talk about how to determine whether your managed heap is healthy. Why does the program throw an OutofMemoryException when the machine has a large amount of memory. Relationship between garbage collection and physical memory virtual memory: If you know this topic well, skip this section. GC needs to allocat

CMS (Concurrent Mark Sweep) collector C:concurrent M: Tag (Marking) object: GC must remember which objects are available to delete unreachable objects S: Clear (sweeping): Remove unmarked objects and free their memory CMS is a collector with the shortest pause time, and the CMS does not achieve the highest GC efficiency, but it minimizes the downtime of the service at GC. Use the mark-purge algorithm (Mar