< H2 > description < H2 > physical environment 2GB memory < H2 > phenomenon description: < H2 > I have a program (no source code) that uses Netty at the bottom (don t be misled into a problem with NIO, but it may be related to DirectMemory), ther...
is shown below: both the meta-space utilization M and the compressed space utilization CCS are above 95%. What does this mean? Is there a problem? the number of full gc is small, only a few times in many days [root@localhost eversec]-sharp cat temp ...
as shown below, metaspace and CCS account for more than 90%. Does this have a great impact on the process? How to deal with it? $JAVA_HOME bin jstat-gcutil 27553 S0 S1 E OM CCS YGC YGCT FGC FGCT GCT 0.00 100.00 13.05 97.12 94.61 9 0.306 3 0.469 0.77...
the most common passage about CMSFullGCsBeforeCompaction, is: < hr > CMSFullGCsBeforeCompaction is talking about how many more times full GC has to be executed before compression has been done since the last CMS concurrent GC execution. The default is...
what s the difference between CMSInitiatingOccupancyFraction and CMSTriggerRatio as the name implies, it feels like the same concept ...
jvm has its own gc strategy, so what s the point of using System.gc ()? ...
I want to dump all the classes loaded by the virtual machine through the ClassDump in sa-jdi.jar. ClassDump supports dump classes from jvm processes or jvm core dump. for online applications, you should not dump, pid directly if you want to get a co...
java used user-mode threads before 1.2. why did it change to lightweight processes to implement threads? Aren t user-mode threads more efficient? Although the management and scheduling is a little complicated! ...
console keeps outputting: [GC (Allocation Failure) [PSYoungGen: 338275K->4614K(341504K)] 412867K->79382K(1040896K), 0.0107084 secs] [Times: user=0.01 sys=0.00, real=0.01 secs] catalina.sh file is configured as follows: JAVA_OPTS="-serve...
for example, the member variable of a class: Object obj = new Object(); obj is an instance of an object. In a broad sense, it is stored on the "stack " and points to the memory address on the "heap ". Specifically, I have the impression that obj sho...
ladies and gentlemen, I have encountered a problem when using G1. The termination phase of G1 takes more than 90% of the total young gc, which is generally about 100ms, which leads to the failure of the whole program. GC log is as follows: 2018-05-16T...
Why can t JVM tuning be automated? ...
< H2 > the book says: during the concurrent cleanup phase, the user thread is still running, and new garbage may be generated during this period. New garbage cannot be removed this time GC, but can only be cleaned up next time. These rubbish have a profe...
https: www.cnblogs.com ggjuc. this article says: < H2 > 1 CMS will not defragment the heap, so in order to prevent full gc, from causing heap fragmentation, merge the fragments by opening the CMS phase: < H2 > does this mean that after CMS full g...
see a paragraph: < H2 > before Minor GC occurs, the virtual machine checks whether the largest contiguous space available in the old era is larger than the total space of all objects in the new generation. If this condition is true, then Minor GC can e...