g1gc

How does the Garbage-First Garbage Collector work?

由 社会主义新天地 提交于 2019-11-28 15:43:35
Can someone explain how the G1 Garbage Collector works please? I haven't been able to find any comprehensive, easy-to-understand descriptions anywhere yet. Thanks Eugene Kuleshov The collector splits the heap up into fixed-size regions and tracks the live data in those regions. It keeps a set of pointers — the "remembered set" — into and out of the region. When a GC is deemed necessary, it collects the regions with less live data first (hence, "garbage first"). Often, this can mean collecting an entire region in one step: if the number of pointers into a region is zero, then it doesn't need to

Is -XX:+UseG1GC the correct replacement for -Xincgc?

由 风格不统一 提交于 2019-11-27 22:17:29
问题 Currently, we are using the incremental garbage collector by adding -Xincgc to the java command. In JDK 8 this switch is deprecated. So what's the equivalent replacement for it? -XX:+UseG1GC ? Background: The application has a heap of 8GB and creates a lot of short living objects. I noticed that it often paused for some seconds to do garbage collection. Out of curiosity I added the -Xincgc and found that the pauses were gone and overall performance improved ~4 times. Unfortunately, I did not

Zero-garbage large String deserialization in Java, Humongous object issue

由 為{幸葍}努か 提交于 2019-11-27 15:25:10
问题 I am looking for a way to deserialize a String from a byte[] in Java with as little garbage produced as possible. Because I am creating my own serializer and de-serializer, I have complete freedom to implement any solution on the server-side (i.e. when serializing data), and on the client-side (i.e. when de-serializing data). I have managed to efficiently serialize a String without incurring any garbage overhead by iterating through the String's chars ( String.charAt(i) ) and converting each

How does the Garbage-First Garbage Collector work?

由 ぃ、小莉子 提交于 2019-11-27 09:19:13
问题 Can someone explain how the G1 Garbage Collector works please? I haven't been able to find any comprehensive, easy-to-understand descriptions anywhere yet. Thanks 回答1: The collector splits the heap up into fixed-size regions and tracks the live data in those regions. It keeps a set of pointers — the "remembered set" — into and out of the region. When a GC is deemed necessary, it collects the regions with less live data first (hence, "garbage first"). Often, this can mean collecting an entire

Java G1 garbage collection in production

由 非 Y 不嫁゛ 提交于 2019-11-26 23:35:08
Since Java 7 is going to use the new G1 garbage collection by default is Java going to be able to handle an order of magnitude larger heap without supposed "devastating" GC pause times? Has anybody actually implemented G1 in production, what were your experiences? To be fair the only time I have seen really long GC pauses is on very large heaps, much more than a workstation would have. To clarify my question; will G1 open the gateway to heaps in the hundreds of GB? TB? It sounds like the point of G1 is to have smaller pause times, even to the point where it has the ability to specify a maximum

Java G1 garbage collection in production

由 核能气质少年 提交于 2019-11-26 08:43:54
问题 Since Java 7 is going to use the new G1 garbage collection by default is Java going to be able to handle an order of magnitude larger heap without supposed \"devastating\" GC pause times? Has anybody actually implemented G1 in production, what were your experiences? To be fair the only time I have seen really long GC pauses is on very large heaps, much more than a workstation would have. To clarify my question; will G1 open the gateway to heaps in the hundreds of GB? TB? 回答1: It sounds like

java.lang.OutOfMemoryError: GC overhead limit exceeded

由 扶醉桌前 提交于 2019-11-26 01:34:46
问题 I am getting this error in a program that creates several (hundreds of thousands) HashMap objects with a few (15-20) text entries each. These Strings have all to be collected (without breaking up into smaller amounts) before being submitted to a database. According to Sun, the error happens \"if too much time is being spent in garbage collection: if more than 98% of the total time is spent in garbage collection and less than 2% of the heap is recovered, an OutOfMemoryError will be thrown.\".

Java 7 (JDK 7) garbage collection and documentation on G1

由 梦想的初衷 提交于 2019-11-25 20:44:34
Java 7 has been out for a while now, but I cannot find any good resources on the configuration of the garbage collectors , specifically the new G1 collector . My questions: Is G1 the default collector in Java 7 and if not how do I activate G1? What optional settings does g1 have in Java7? Were there any changes made to other collectors like cms or the parallel collector in Java 7? Where can I find good documentation on garbage collection in Java 7? The G1 garbage collector is not the default in my installation of Java, version 1.7.0_01. You can see for yourself by using with some extra command
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