Java G1 GC |驻留内存高于NMT保留内存
使用G1GC的java进程使用的驻留内存远远高于XMX和NMT报告的内存Java G1 GC |驻留内存高于NMT保留内存,java,memory-management,memory-leaks,g1gc,Java,Memory Management,Memory Leaks,G1gc,使用G1GC的java进程使用的驻留内存远远高于XMX和NMT报告的内存 java -version openjdk version "11.0.6" 2020-01-14 LTS OpenJDK Runtime Environment 18.9 (build 11.0.6+10-LTS) OpenJDK 64-Bit Server VM 18.9 (build 11.0.6+10-LTS, mixed mode, sharing) NMT报告了大约80GB的内存使用情况,但是,java进程的
java -version
openjdk version "11.0.6" 2020-01-14 LTS
OpenJDK Runtime Environment 18.9 (build 11.0.6+10-LTS)
OpenJDK 64-Bit Server VM 18.9 (build 11.0.6+10-LTS, mixed mode, sharing)
NMT报告了大约80GB的内存使用情况,但是,java进程的驻留内存超过了85GB。随着时间的推移,两者之间的差距不断扩大。对于运行同一应用程序的另一个VM,驻留内存超过95GB,而NMT内存也只有82GB。由于这种不断增长的内存占用,最终,应用程序被OS oom杀手杀死
是什么导致了两者之间的差异?如何减少应用程序的内存占用,使其更具可预测性
top output
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
787 root 20 0 99.9g 85.4g 22120 S 1053 66.8 11904:11 java
JVM Arguments
/usr/bin/java -Xms75g -Xmx75g -XX:NativeMemoryTracking=summary -XX:MaxGCPauseMillis=50
-XX:G1RSetSparseRegionEntries=4096 -XX:G1HeapRegionSize=32M
-Xlog:gc*=info,gc+phases=debug:file=/var/log/gc.log:time,uptimemillis,level,tags:filecount=5,filesize=50M -XX:+UseG1GC
Native Memory Tracking:
Total: reserved=81376MB, committed=80879MB
- Java Heap (reserved=76800MB, committed=76800MB)
(mmap: reserved=76800MB, committed=76800MB)
- Class (reserved=65MB, committed=65MB)
(classes #9993)
( instance classes #9216, array classes #777)
(malloc=1MB #29050)
(mmap: reserved=64MB, committed=63MB)
( Metadata: )
( reserved=64MB, committed=63MB)
( used=62MB)
( free=1MB)
( waste=0MB =0.00%)
- Thread (reserved=348MB, committed=35MB)
(thread #345)
(stack: reserved=346MB, committed=33MB)
(malloc=1MB #2072)
(arena=1MB #688)
- Code (reserved=244MB, committed=62MB)
(malloc=2MB #6831)
(mmap: reserved=242MB, committed=59MB)
- GC (reserved=3239MB, committed=3239MB)
(malloc=356MB #58172)
(mmap: reserved=2883MB, committed=2883MB)
- Compiler (reserved=2MB, committed=2MB)
(malloc=3MB #2963)
- Internal (reserved=16MB, committed=16MB)
(malloc=16MB #8415)
- Other (reserved=643MB, committed=643MB)
(malloc=643MB #296)
- Symbol (reserved=12MB, committed=12MB)
(malloc=10MB #122802)
(arena=3MB #1)
- Native Memory Tracking (reserved=4MB, committed=4MB)
(tracking overhead=4MB)