发现一个应用报错502,查看日志后得知错误信息
Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x00000007d3000000, 536870912, 0) failed; error='Cannot allocate memory' (errno=12)
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (malloc) failed to allocate 536870912 bytes for committing reserved memory.
# An error report file with more information is saved as:
# /data/tomcat/bin/hs_err_pid26832.log
ps -ef是看不到这个应用的。
查看/data/tomcat/bin/hs_err_pid26832.log得知
# There is insufficient memory for the Java Runtime Environment to continue.
# Cannot create GC thread. Out of system resources.
# Possible reasons:
# The system is out of physical RAM or swap space
# In 32 bit mode, the process size limit was hit
# Possible solutions:
# Reduce memory load on the system
# Increase physical memory or swap space
# Check if swap backing store is full
# Use 64 bit Java on a 64 bit OS
# 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 (gcTaskThread.cpp:46), pid=17285, tid=47629249568816
#
# JRE version: 6.0_43-b01
# Java VM: Java HotSpot(TM) 64-Bit Server VM (20.14-b01 mixed mode linux-amd64 compressed oops)
从日志中分析,可能原因有两个:
一、可能物理内存不足
二、在32位操作系统下,系统进程数达到上限了。
然后分析服务器内存,可用物理内存以及swap空间都足够,问题可能发生在系统进程数达到上限(我的64位操作系统也是这个问题)。
通过命令查看系统限制:ulimit -a查看open files的值为1024,不够大,尝试通过设大该值:
1、vi /etc/security/limits.conf
2、在文件最下方加上如下代码 root - nofile 65535 保存(ubuntu下不能使用* - nofile 65535,不起作用,必须注明用户)
ssh退出后重新登录
此时通过ulimit -a或ulimit -n可以得到结果65535 启动tomcat问题解决