学者网学科建设网站,怎么做网站背景图,没有网站做淘宝客,购物商城英语1. 絮絮叨叨 工作中#xff0c;Java服务因为fatal error#xff08;致命错误#xff0c;笔者称其为jvm crash#xff09;#xff0c;在服务运行日志中出现了致命错误的概要信息#xff1a; #
# A fatal error has been detected by the Java Runtime Environment:
#
# S…1. 絮絮叨叨 工作中Java服务因为fatal error致命错误笔者称其为jvm crash在服务运行日志中出现了致命错误的概要信息 #
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc0x000000010a7d52e8, pid47989, tid11011
#
# JRE version: OpenJDK Runtime Environment Temurin-17.0.610 (17.0.610) (build 17.0.610)
# Java VM: OpenJDK 64-Bit Server VM Temurin-17.0.610 (17.0.610, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, bsd-amd64)
# Problematic frame:
# V [libjvm.dylib0xada2e8] Unsafe_GetByte(JNIEnv_*, _jobject*, _jobject*, long)0xd8
#
# No core dump will be written. Core dumps have been disabled. To enable core dumping, try ulimit -c unlimited before starting Java again
#
# An error report file with more information is saved as:
# /Users/xxx/IdeaProjects/study/hs_err_pid47989.log
#
# If you would like to submit a bug report, please visit:
# https://github.com/adoptium/adoptium-support/issues
#服务运行在k8s中由于未提前设置fatal error日志的路径挂载到宿主机目录容器重启后该日志会丢失无法深入排查原因 因此需要查询jvm的配置将fatal error日志写入指定目录保证该日志持久化存储到宿主机磁盘
2. 配置jvm参数实现日志的持久化存储
2.1 -XX:ErrorFile配置fatal error路径 通过查阅资料了解到可以通过-XX:ErrorFilefilename配置hs_err日志的路径 下面的示例中将fatal error的日志写入指定目录文件名的%p会动态替换成改Java程序的PID进程id -XX:ErrorFile/var/log/java/java_error%p.log默认将fatal error日志写入Java程序的working directory且文件名为hs_err_pid.log如果空间不足、权限不够等原因fatal error日志将被写入系统的临时目录 详情见JDK官网的说明 JDK 8A Fatal Error LogJDK 17A Fatal Error LogCommand-Line Options
2.2 笔者的错误配置 考虑到服务每次重启的pid基本一致如果多次出现fatal error只使用pid的日志会被覆盖。 笔者结合之前配置heap dump的经验添加了%t以生成类似2023-08-16_23-33-08的时间戳 -XX:ErrorFile/data_path/var/log/hs_err_pid%p_%t.log当再一次发生fatal error时发现日志文件名为hs_err_pid6_%t.log即%t未按照预期进行解析
2.3 -XX:OnError配置更新文件名 受问题How to specify a unique name for the JVM crash log files?启发配置-XX:OnError在日志生成后执行shell命令为其添加时间戳 -XX:ErrorFile/data_path/var/log/hs_err.log
-XX:OnErrortimedate %Y%m%d_%H%M%S mv /data_path/var/log/hs_err.log /data_path/var/log/hs_err_\${time}.log3. 如何触发fatal error 不管是验证相关JVM参数的配置还是学习查看fatal error日志的内容学会如何在触发fatal error是非常必要的 参考Write Java code to crash the java virtual machine通过如下代码可以成功在本地触发fatal error import sun.misc.Unsafe;
import java.lang.reflect.Field;public class CrashTest {public static void main(String... args) throws Exception {getUnsafe().getByte(0);}private static Unsafe getUnsafe() throws NoSuchFieldException, IllegalAccessException {Field theUnsafe Unsafe.class.getDeclaredField(theUnsafe);theUnsafe.setAccessible(true);return (Unsafe) theUnsafe.get(null);}
}4. 待交流的问题
4.1 本地验证OK 按照上面的描述笔者为CrashTest配置了如下JVM参数 -XX:ErrorFile/data_path/study/hs_err.log
-XX:OnErrortimedate %Y%m%d_%H%M%S echo $time mv /data_path/hs_err.log /data_path//hs_err_${time}.log程序运行起来后打印如下信息 #
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc0x000000010a49e2e8, pid56245, tid11011
#
# JRE version: OpenJDK Runtime Environment Temurin-17.0.610 (17.0.610) (build 17.0.610)
# Java VM: OpenJDK 64-Bit Server VM Temurin-17.0.610 (17.0.610, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, bsd-amd64)
# Problematic frame:
# V [libjvm.dylib0xada2e8] Unsafe_GetByte(JNIEnv_*, _jobject*, _jobject*, long)0xd8
#
# No core dump will be written. Core dumps have been disabled. To enable core dumping, try ulimit -c unlimited before starting Java again
#
# An error report file with more information is saved as:
# /data_path/hs_err.log
#
# If you would like to submit a bug report, please visit:
# https://github.com/adoptium/adoptium-support/issues
#
#
# -XX:OnErrortimedate %Y%m%d_%H%M%S mv /data_path/hs_err.log /data_path/hs_err_${time}.log
# Executing /bin/sh -c timedate %Y%m%d_%H%M%S mv /data_path/hs_err.log /data_path/hs_err_${time}.log ...最终fatal error日志的文件名为hs_err_20230827_202458.log符合预期
4.2 测试环境验证失败 将此配置移动到线上服务却发现fatal error日志的文件名为hs_err_.log不符合预期 怀疑 未能正确解析${time} 一个问答 How to add the timestamp of the fatal error occurrence to Java fatal error log filename遇到了与笔者类似的问题 -XX:ErrorFile{{ .Values.server.data_dir }}/var/log/hs_err.log
-XX:OnErrormv {{ .Values.server.data_dir }}/var/log/hs_err.log {{ .Values.server.data_dir }}/var/log/hs_err_\$(date %Y%m%d_%H%M%S).log虽然更新了配置但是由于引发fatal error的错误已被修复无法验证该配置的效果 要么等到后面出现fatal error时验证效果要么回退镜像版本触发fatal error 若后续有机会验证该配置笔者会更新结果暂时在此记录可能的可行解决方案
