g1gc

问题 Jstat tool gives stats regarding young gc time and full gc time along with other information. As far as I know, Full GC in G1 GC consists of following phases : 1) Concurrent Marking (not Stop the world) 2) Remarking (Stop the world) 3) Reclaimation of empty regions (Stop the world) 4) Reclaimation of partially empty old regions through mixed gc (Happens over the time) Now, I want to know jstat full gc time measures time for which of the phases ? If Phase 1 and 2 are not considered for full gc

问题 This question already has answers here : How does Java GC call finalize() method? (4 answers) How finalizable objects takes at least 2 garbage collection cycles before it can be reclaimed? (2 answers) why allocation phase can be increased if we override finalize method? (1 answer) Closed 11 months ago . My understanding is that GCs like ParallelGC and G1 are "generational" collectors. Garbage Collection almost happens as a byproduct, since you move all live objects to a new heap region and

问题 This question already has answers here : How does Java GC call finalize() method? (4 answers) How finalizable objects takes at least 2 garbage collection cycles before it can be reclaimed? (2 answers) why allocation phase can be increased if we override finalize method? (1 answer) Closed 11 months ago . My understanding is that GCs like ParallelGC and G1 are "generational" collectors. Garbage Collection almost happens as a byproduct, since you move all live objects to a new heap region and

问题 This question already has answers here : How does Java GC call finalize() method? (4 answers) How finalizable objects takes at least 2 garbage collection cycles before it can be reclaimed? (2 answers) why allocation phase can be increased if we override finalize method? (1 answer) Closed 11 months ago . My understanding is that GCs like ParallelGC and G1 are "generational" collectors. Garbage Collection almost happens as a byproduct, since you move all live objects to a new heap region and

问题 This question already has answers here : How does Java GC call finalize() method? (4 answers) How finalizable objects takes at least 2 garbage collection cycles before it can be reclaimed? (2 answers) why allocation phase can be increased if we override finalize method? (1 answer) Closed 11 months ago . My understanding is that GCs like ParallelGC and G1 are "generational" collectors. Garbage Collection almost happens as a byproduct, since you move all live objects to a new heap region and

问题 According to the documentation, XX:InitiatingHeapOccupancyPercent Sets the Java heap occupancy threshold that triggers a marking cycle. The default occupancy is 45 percent of the entire Java heap. In my current environment, that does not happen. My G1 garbage collection configuration is as follows -Xms25000m -Xmx25000m -XX:+UseG1GC -XX:MaxGCPauseMillis=1000 -XX:GCTimeRatio=99 -XX:InitiatingHeapOccupancyPercent=70 -XX:MaxTenuringThreshold=8 -XX:+UnlockExperimentalVMOptions -XX

问题 I've read a few descriptions of different times printed in G1GC logs but couldn't really prove/understand when I produced them locally. For example, following log was produced on my PC with Java 11. I wanted to know, what's the difference between 0.500ms in the first line vs 0.01s in the second? Was the application paused (because of STW) for 0.500ms or for 10ms (0.01s)? I tried tools like GCeasy, it shows max pause time of 10ms, and in cases where Real = 0.00, GCeasy shows min pause of 0ms.

问题 I've read a few descriptions of different times printed in G1GC logs but couldn't really prove/understand when I produced them locally. For example, following log was produced on my PC with Java 11. I wanted to know, what's the difference between 0.500ms in the first line vs 0.01s in the second? Was the application paused (because of STW) for 0.500ms or for 10ms (0.01s)? I tried tools like GCeasy, it shows max pause time of 10ms, and in cases where Real = 0.00, GCeasy shows min pause of 0ms.

问题 I've read a few descriptions of different times printed in G1GC logs but couldn't really prove/understand when I produced them locally. For example, following log was produced on my PC with Java 11. I wanted to know, what's the difference between 0.500ms in the first line vs 0.01s in the second? Was the application paused (because of STW) for 0.500ms or for 10ms (0.01s)? I tried tools like GCeasy, it shows max pause time of 10ms, and in cases where Real = 0.00, GCeasy shows min pause of 0ms.

问题 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 remembered-set? Cause all the blogs to say the reason why we use remembered-set is we don't need to check every region to see if there is an object that is referenced by GC-Roots 回答1: You need to understand what Card Table is first, IMO. How do you scan only young generation region and clean it, if