I'm currently having problems with very long garbage collection times. please see the followig. My current setup is that I'm using a -Xms1g and -Xmx3g. my application is using java 1.4.2. I don't h...

Could you kindly help us with a query we have regarding a Java 8 Spring boot application running in Docker containers in ECS? After migrating to Java 17, we observed a significant 1GB increase in m...

I'm currently looking into G1 GC in latest Java 8 version. I have issues with "Humongous Allocation" so I wanna know how big my region size is. How can I find out how big the region size is set? ...

I've got short-living applications which usually (but not always) do not need any GC (fits in heap, epsilon GC proves this by not causing an OOM). Interestingly, G1 still kicks in very early even t...

For garbage first collector, young gc means performing gc in young generation only and mixed gc would clean both young and old generation. So what is full gc? Why it lasts longer than mixed gc? I...

I looked into differences between various garbage collectors available for JVM. Here is the answer explaining the main differences between them : https://mcmap.net/q/359283/-when-to-choose-serialgc...

The G1GC old generation committed heap goes up over time (about 5 to 6 days on production) but the old generation used heap does not. The Eden and survivor heap is forced to decrease to the minimum...

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? Back...

I am trying to use the G1GC garbage collector for spark job but I get a Error: Invalid argument to --conf: -XX:+UseG1GC I tried using these options but haven't been able to get it working spark...

What's the difference between cms and g1 garbage collector which makes g1 better? Most of places it is said that this is because in G1, heap is divided into regions and then collection of regions a...

I'm trying to understand what the -XX:G1ReservePercent actually does. The descriptions I found in the official documentation are not really comprehensive: Sets the percentage of reserve memory t...

I just read some blogs about G1 algorithm. The usage of remembered-set is confused to me. Here is what I think: Since we can use DFS to walk through every reference from GC-Roots, why do we need...

I am trying to solve a problem where the heap memory is going beyond 90 percent in my java service. Below is the heap configuration I am using, -Xms6144m \ -Xmx6144m \ -verbose:gc \ -XX:G1Hea...

After reading some answers like this and JEP-346, I have realised that the G1 does release memory back to the OS. However does it release memory back to the OS, even to the point that current memo...

I would like to programmatically find the number of humongous regions before/after a GC has run, in order to report it to an external monitoring service. I'm able to find information like GC actio...

My server is using 1.8.0_92 on CentOS 6.7, GC param is '-Xms16g -Xmx16g -XX:+UseG1GC'. So the default InitiatingHeapOccupancyPercent is 45, G1HeapWastePercent is 5 and G1MixedGCLiveThresholdPercent...

I have a question about g1gc. These are the heap usage graph. The above is -Xms4g -Xmx4g. The bottom is -Xms8g -Xmx8g. I don't know why the 8g option causes g1gc to happen more often. Other ...

In Java 6 we used to use the following GC configuration to prevent Perm Gen OutOfMemoryException after several redeployments of our app: -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled We'...

When G1 decides it needs to start doing mixed collections, it aggressively shrinks our Eden space from 10g to about 1g. {Heap before GC invocations=294 (full 0): garbage-first heap total 20480000...

Java 10 reduces Full GC pause times by iteratively improving on its existing algorithm. -XX:ParallelGCThreads As I understood it G1 does not run its collection cycles concurrently with our appli...

When configuring the G1GC we have two kinds of thread count: -XX:ParallelGCThreads and -XX:ConcGCThreads. What is the difference? How they are going to impact? Any reference is appreciated.

I was running my surefire tests and it got me into GC Overhead limit. However, after analyzing memory statistics and snapshots I realized that almost 800 MB was wasted in String Duplication. Look...

We have a java application which need almost Realtime response. But we are also seeing pauses up to 8sec. Special running condition: In some intervals the application would serialize a huge da...

I'm tuning our product for G1GC, and as part of that testing, I'm experiencing regular segfaults on my Spark Workers, which of course causes the JVM to crash. When this happens, the Spark Worker/Ex...

I switched 1 instance (2 vCPU, 2GB RAM, load ~4k req/sec) to Java 9 (from latest Java 8). For a while, everything was fine and CPU usage was same as before. However, after ~6 hours CPU consumption ...