Java 严重错误文件显示内存不足，而堆转储要小得多

Question

我是运行基于 Java 的应用程序，由于内存不足，它正在崩溃。 hs_err 的一些输出片段：

#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 24696061952 bytes for committing reserved memory.
# Possible reasons:
#   The system is out of physical RAM or swap space
#   The process is running with CompressedOops enabled, and the Java Heap may be blocking the growth of the native heap
# Possible solutions:
#   Reduce memory load on the system
#   Increase physical memory or swap space
#   Check if swap backing store is full
#   Decrease Java heap size (-Xmx/-Xms)
#   Decrease number of Java threads
#   Decrease Java thread stack sizes (-Xss)
#   Set larger code cache with -XX:ReservedCodeCacheSize=
# This output file may be truncated or incomplete.
#
#  Out of Memory Error 
#
# JRE version:  (8.0_275-b01) (build )
# Java VM: OpenJDK 64-Bit Server VM
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#

但是当我进行堆转储时，它显示大约 8GB 的内存。我的 jvm 参数是：-Xmx30720m -Xms30720m -Xmn7168m -Xss8m

top命令显示

 PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
 20   0 82.7g  36g  33m S 10.6 61.9  63594:19 java

/proc/meminfo

/proc/meminfo:
MemTotal:       61833192 kB
MemFree:         2235872 kB
MemAvailable:   20808016 kB
Buffers:          213036 kB
Cached:         17876428 kB
SwapCached:            0 kB
Active:         55994452 kB
Inactive:        1816412 kB
Active(anon):   39721444 kB
Inactive(anon):      132 kB
Active(file):   16273008 kB
Inactive(file):  1816280 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:             0 kB
SwapFree:              0 kB
Dirty:              1312 kB
Writeback:             0 kB
AnonPages:      39721564 kB
Mapped:           107292 kB
Shmem:               140 kB
Slab:            1280320 kB
SReclaimable:    1121808 kB
SUnreclaim:       158512 kB
KernelStack:       67824 kB
PageTables:       103072 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:    30916596 kB
Committed_AS:   75073316 kB
VmallocTotal:   34359738367 kB
VmallocUsed:           0 kB
VmallocChunk:          0 kB
AnonHugePages:         0 kB
ShmemHugePages:        0 kB
ShmemPmdMapped:        0 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:       12288 kB
DirectMap2M:    62902272 kB

我不明白如何在此处进行调试，因为堆转储中没有显示任何内容，与健康运行应用程序的堆转储相比，堆转储更小。知道如何识别程序的哪一部分占用了内存吗？

Answer 1

您已使用 -Xms 强制 JVM 在 JVM 启动时获得约 30GB。

它尝试过，但失败了。它只获得了8GB。它需要另外 22 GB 但无法获得。这就是错误消息告诉您的内容。这与堆只有 8GB 的转储一致。

您要求的比 OS 所能提供的更多。您需要弄清楚 OS 中的一般情况。

您的应用程序代码可能不涉及。 JVM 仍在根据您的命令行选项初始化其堆。

Java 严重错误文件显示内存不足，而堆转储要小得多

Java fatal error file showing insufficient memory while heap dump is much smaller

java

jvm

out-of-memory

heap-memory