[转帖]一次操作系统报错OutOfMemory Error的处理记录

一次,操作系统,报错,outofmemory,error,处理,记录 · 浏览次数 : 0

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## Java Memory Allocation Failure The error message indicates insufficient memory for the Java Runtime Environment (JRE). The following details are extracted from the provided log file: * **Error:** `# There is insufficient memory for the Java Runtime Environment to continue.# Native memory allocation (mmap) failed to map 357564416 bytes for committing reserved memory.` * **Possible reasons:** * **Out of physical RAM or swap space:** The system is short on available memory to fulfill the memory allocation request. * **CompressedOops enabled and blocking growth of the Java heap:** CompressedOops may be preventing the Java heap from expanding beyond 4GB, potentially blocking the native heap growth. * **Other issues:** The system may be experiencing memory pressure due to other processes or high resource consumption. ## Solutions 1. **Reduce memory load on the system:** * Close any unnecessary background programs or services. * Reduce the number of threads and threads within your application. * Use lightweight libraries instead of heavyweight libraries. 2. **Increase available memory:** * **Set larger `-Xmx` or `-Xms` parameters:** This allows more memory to be allocated at startup. However, consider the impact on performance and memory usage. * **Use a larger virtual memory space:** Allocate memory beyond 4GB using `-Xms512m` and `-Xmx1024m` parameters. 3. **Check swap backing store:** * Ensure sufficient space is available in the swap area. * If insufficient, consider increasing the available swap space or setting a larger swap file. 4. **Adjust `vm.overcommit_memory` parameter:** * Set `vm.overcommit_memory` to 0 to allow the system to dynamically allocate memory as needed. * Alternatively, set it to 1 for always allow overcommit. 5. **Restart the Tomcat service with `-XX:HeapBaseMinAddress` parameter:** * This parameter specifies the minimum address where the Java heap can be allocated. Setting it to 4GB in this case allows the Java heap to grow beyond 4GB. 6. **Monitor memory consumption:** * Use tools like `free -m` to monitor memory usage and identify any memory leaks. 7. **Consider the cause of memory pressure:** * Investigate other potential causes of memory issues, such as high resource usage by other processes or system errors. ## Conclusion The error indicates memory limitations, either due to insufficient physical memory or memory pressure due to the CompressedOops configuration. By implementing the suggested solutions, you should be able to resolve the memory allocation failure and ensure Java application startup.

正文

在启动公司内嵌的tomcat容器时出现报错, 如下:


# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (malloc) failed to allocate 160088 bytes for AllocateHeap
# An error report file with more information is saved as:
# /users/xxx/hs_err_pidxxxx.log

然后查看/users/xxx/hs_err_pidxxxx.log内容:


#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 357564416 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=
#   JVM is running with Unscaled Compressed Oops mode in which the Java heap is
#     placed in the first 4GB address space. The Java Heap base address is the
#     maximum limit for the native heap growth. Please use -XX:HeapBaseMinAddress
#     to set the Java Heap base and to place the Java Heap above 4GB virtual address.
# This output file may be truncated or incomplete.
#
#  Out of Memory Error (os_linux.cpp:2749), pid=4252, tid=0x00007f3f38bb5700
#
# JRE version:  (8.0_201-b09) (build )
# Java VM: Java HotSpot(TM) 64-Bit Server VM (25.201-b09 mixed mode linux-amd64 compressed oops)
# Core dump written. Default location: /users/ems/core or core.4252 (max size 521000 kB). To ensure a full core dump, try "ulimit -c unlimited" before starting Java again
#
...

翻译过来就是本地内存分配失败, 可能的原因有两种

系统物理内存或虚拟内存不足
程序在压缩指针模式下运行, Java堆会阻塞本地堆的增长

然后使用free -m命令查询, 发现内存足够:


             total       used       free     shared    buffers     cached
Mem:          7983       5415       2568          0        170       1460
-/+ buffers/cache:       3784       4199
Swap:        15257         71      15186

那么尝试按第二个问题进行解决, 可能的方案有两种:

禁止使用压缩指针模式
1. 方法: 在catalina.sh中JAVA_OPTS的值后面添加-XX:-UseCompressedOops, 再重启tomcat
将Java堆的起始地址设置成使Java堆大小+起始地址大于4G,
1. 原因: 请参考 https://blogs.oracle.com/poonam/running-on-a-64bit-platform-and-still-running-out-of-memory,
2. 方法: 在这里我将起始地址简单直接的设为4G即4294967296

在尝试过这两种方法后发现依然报同样的错误
这时我在想会不会是堆内存过大, 导致系统无法分配内存, 于是进行尝试: 把堆内存减少一半, 看看效果.

方法: 在在catalina.sh中JAVA_OPTS的值中把原来的-Xms1024m -Xmx2048m改为-Xms512m -Xmx1024m, 再重启tomcat

结果JVM启动成功, 问题解决.

后续思考: 为什么在可用内存充足的情况下系统无法分配给JVM更多内存? 一直没有想到完美的解释, 如果有明白的兄弟可以指教一下.

尝试对后续思考进行解答: 原因应该还是内存不足, 可能操作系统会预留一些内存, 而我的机器上默认的启动参数是-Xms1024m -Xmx2048m, 可能已经超过了系统允许分配的最高值, 因此无法分配内存. 当我使用java -Xms10m -Xmx20m可以启动成功, java -Xms500m -Xmx2000m会失败, 因此, 应该还是内存不足的问题

对后续思考的最终解答及该问题的完美解决方案:

这个问题是由于/proc/meminfo下的vm.overcommit_memory被设置成不允许overcommit造成的

首先了解一下overcommit的意思: 用户进程申请的是虚拟地址, 而这个虚拟地址是不允许任意申请的, 因为虚拟内存需要物理内存做支撑, 如果分配太多虚拟内存, 会对性能参数影响. overcommit就是对虚拟内存的过量分配

vm.overcommit_memory的用处: 控制过量分配的策略. 这个参数一共有3个可选值:

0: Heuristic overcommit handling. 就是由操作系统自己决定过量分配策略
1: Always overcommit. 一直允许过量分配
2: Don't overcommit. 不允许过量分配

在这个案例里面, 使用sysctl vm.overcommit_memory来查看, 发现vm.overcommit_memory = 2, 即采用的是不允许过量分配的设置. 而在错误日志中也证明了这一点:


CommitLimit:    15951192 kB
Committed_AS:   15837036 kB

Committed_AS: OS会预测启动这个程序时, 所有的进程可能会用到多少的内存, 如果超过了CommitLimit, 就会报错
解决方案是sudo sysctl vm.overcommit_memory=0, 即vm.overcommit_memory = 0, 允许系统自己决定过量分配策略

原文地址：https://www.jianshu.com/p/3f8692eb3660

转载于:https://www.cnblogs.com/jpfss/p/11052535.html

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