问题描述
我正在运行一个基于 Java 的应用程序，它由于内存不足而崩溃。 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
顶部命令显示
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
我不明白如何在这里调试，因为堆转储中没有任何显示，与健康运行的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内存吗？
解决方法
您已使用 -Xms 强制 JVM 在 JVM 启动时获得 ~30GB。
尝试过，但失败了。它只获得了8GB。它需要另一个 22-ish GB，但无法获得。这就是错误消息告诉你的。这与说堆只有 8GB 的转储一致。
您要求的超出了操作系统所能提供的范围。您需要弄清楚操作系统的总体情况。
可能不涉及您的应用程序代码。 JVM 仍在根据您的命令行选项初始化其堆。