JVM致命错误日志(hs

最近两天测试环境有一个服务总是会挂（两到三天一次），JVM虚拟机总是会崩溃。所以有必要了解JVM崩溃的原因是什么。

当JVM发生致命错误导致崩溃时，会生成一个hs_err_pid_xxx.log这样的文件，该文件包含了导致 JVM crash 的重要信息，我们可以通过分析该文件定位到导致 JVM Crash 的原因，从而修复保证系统稳定。

默认情况下，该文件是生成在工作目录下的，当然也可以通过 JVM 参数指定生成路径：

-XX:ErrorFile=/var/log/hs_err_pid<pid>.log

这个文件主要包含如下内容：

日志头文件导致 crash 的线程信息所有线程信息安全点和锁信息堆信息本地代码缓存编译事件gc 相关记录jvm 内存映射jvm 启动参数服务器信息

下面就根据这个文件内容逐步解析。

日志头文件

内容如下

# # A fatal error has been detected by the Java Runtime Environment: # # SIGSEGV (0xb) at pc=0x0000003797807a91, pid=29071, tid=139901421901568 # # JRE version: Java(TM) SE Runtime Environment (8.0_45-b14) (build 1.8.0_45-b14) # Java VM: Java HotSpot(TM) 64-Bit Server VM (25.45-b02 mixed mode linux-amd64 compressed oops) # Problematic frame: # C [libresolv.so.2+0x7a91] __libc_res_nquery+0x1c1 # # Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again # # If you would like to submit a bug report, please visit: # http://bugreport.java.com/bugreport/crash.jsp # The crash happened outside the Java Virtual Machine in native code. # See problematic frame for where to report the bug. #

这段内容主要简述了导致 JVM Crash 的原因。常见的原因有 JVM 自身的 bug，应用程序错误，JVM 参数，服务器资源不足，JNI 调用错误等。当然还有一些版本和配置信息，

SIGSEGV (0xb) at pc=0x0000003797807a91, pid=29071, tid=139901421901568

非预期的错误被 JRE 检测到了，其中

SIGSEGV ：信号量0xb ：信号码pc=0x0000003797807a91 ：程序计数器的值pid=29071 ：进程号tid=139901421901568 ：线程号

SIGSEGV(0xb) 表示 JVM Crash 时正在执行 JNI 代码，常见的描述还有EXCEPTION_ACCESS_VIOLATION，该描述表示 JVM Crash 时正在执行 JVM 自身的代码，这往往是因为 JVM 的 Bug 导致的 Crash；另一种常见的描述是EXCEPTION_STACK_OVERFLOW，该描述表示这是个栈溢出导致的错误，这往往是应用程序中存在深层递归导致的。

# JRE version: Java(TM) SE Runtime Environment (8.0_45-b14) (build 1.8.0_45-b14) # Java VM: Java HotSpot(TM) 64-Bit Server VM (25.45-b02 mixed mode linux-amd64 compressed oops)

这个信息比较重要，问题帧信息：

C 表示帧类型为本地帧，还有其他类型：

j ： 解释的Java帧V : 虚拟机帧v ：虚拟机生成的存根栈帧J：其他帧类型，包括编译后的Java帧

[libresolv.so.2+0x7a91] __libc_res_nquery+0x1c1和程序计数器（pc）表达的含义一样，但是用的是本地so库+偏移量的方式。

导致 crash 的线程信息

内容如下：

--------------- T H R E A D --------------- Current thread (0x0000000001e94800): JavaThread "pool-1-thread-2" [_thread_in_native, id=30111, stack(0x00007f3d567e5000,0x00007f3d568e6000)] siginfo: si_signo: 11 (SIGSEGV), si_code: 1 (SEGV_MAPERR), si_addr: 0x0000000000000003 Registers: RAX=0x0000000000000000, RBX=0x0000000000000000, RCX=0x0000000000000000, RDX=0x0000000000000050 RSP=0x00007f3d568e2280, RBP=0x00007f3d568e2570, RSI=0x0000000000000000, RDI=0x00000000ffffffff R8 =0x0000000000000000, R9 =0x0000000000000000, R10=0x000000000007a337, R11=0x0000000000000213 R12=0x00007f3d568e2ef0, R13=0x00007f3d568e22b0, R14=0x0000000000000000, R15=0x00007f3d568e5db8 RIP=0x0000003797807a91, EFLAGS=0x0000000000010246, CSGSFS=0x0000000000000033, ERR=0x0000000000000004 TRAPNO=0x000000000000000e Top of Stack: (sp=0x00007f3d568e2280) 0x00007f3d568e2280: b8e4bfb900000800 00007f3d568e3760 0x00007f3d568e2290: 00007f3d568e3758 00007f3d568e377c 0x00007f3d568e22a0: 00007f3d568e3778 6f6e6b6e56a88a58 0x00007f3d568e22b0: 00000100000149a0 7a68710800000000 0x00007f3d568e22c0: 6970067363642d78 6d6f63036e61676e ....省略 Instructions: (pc=0x0000003797807a91) 0x0000003797807a71: 48 89 45 b8 48 8b 4d b8 0f b6 51 03 89 d3 83 e3 0x0000003797807a81: 0f 75 0d 0f b7 49 06 66 c1 c9 08 66 85 c9 75 4f 0x0000003797807a91: 0f b6 48 03 bf 0f 00 00 00 40 20 cf 75 0d 0f b7 0x0000003797807aa1: 70 06 66 c1 ce 08 66 85 f6 75 34 83 e1 0f 83 e2 Register to memory mapping: RAX=0x0000000000000000 is an unknown value RBX=0x0000000000000000 is an unknown value RCX=0x0000000000000000 is an unknown value RDX=0x0000000000000050 is an unknown value RSP=0x00007f3d568e2280 is pointing into the stack for thread: 0x0000000001e94800 RBP=0x00007f3d568e2570 is pointing into the stack for thread: 0x0000000001e94800 ... 省略 Stack: [0x00007f3d567e5000,0x00007f3d568e6000], sp=0x00007f3d568e2280, free space=1012k Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code) C [libresolv.so.2+0x7a91] __libc_res_nquery+0x1c1 C [libresolv.so.2+0x7fd1] Java frames: (J=compiled Java code, j=interpreted, Vv=VM code) J 15056 java.net.Inet6AddressImpl.lookupAllHostAddr(Ljava/lang/String;)[Ljava/net/InetAddress; (0 bytes) @ 0x00007f3d7492af8c [0x00007f3d7492af40+0x4c] J 14966 C1 java.net.InetAddress.getAddressesFromNameService(Ljava/lang/String;Ljava/net/InetAddress;)[Ljava/net/InetAddress; (245 bytes) @ 0x00007f3d75466754 [0x00007f3d754662c0+0x494] J 14291 C2 java.net.InetAddress.getAllByName(Ljava/lang/String;Ljava/net/InetAddress;)[Ljava/net/InetAddress; (387 bytes) @ 0x00007f3d7534b718 [0x00007f3d7534ae20+0x8f8] J 14178 C1 java.net.InetSocketAddress.<init>(Ljava/lang/String;I)V (47 bytes) @ 0x00007f3d752ce0f4 [0x00007f3d752cdec0+0x234] j sun.security.ssl.SSLSocketImpl.<init>(Lsun/security/ssl/SSLContextImpl;Ljava/lang/String;ILjava/net/InetAddress;I)V+144 j sun.security.ssl.SSLSocketFactoryImpl.createSocket(Ljava/lang/String;ILjava/net/InetAddress;I)Ljava/net/Socket;+13 j com.ufclub.daq.qhzx.utils.SSLProtocolSocketFactory.createSocket(Ljava/lang/String;ILjava/net/InetAddress;I)Ljava/net/Socket;+15 .... 省略代码

这部分内容包含出发 JVM 致命错误的线程详细信息和线程栈。

线程信息

Current thread (0x0000000001e94800): JavaThread "pool-1-thread-2" [_thread_in_native, id=30111, stack(0x00007f3d567e5000,0x00007f3d568e6000)] 0x0000000001e94800：出错的线程指针JavaThread：线程类型，可能的类型包括 JavaThread：Java线程 VMThread : JVM 的内部线程 CompilerThread：用来调用JITing，实时编译装卸class 。 通常，jvm会启动多个线程来处理这部分工作，线程名称后面的数字也会累加，例如：CompilerThread1 GCTaskThread：执行gc的线程 WatcherThread：JVM 周期性任务调度的线程，是一个单例对象 ConcurrentMarkSweepThread：jvm在进行CMS GC的时候，会创建一个该线程去进行GC，该线程被创建的同时会创建一个SurrogateLockerThread（简称SLT）线程并且启动它，SLT启动之后，处于等待阶段。CMST开始GC时，会发一个消息给SLT让它去获取Java层Reference对象的全局锁：Lock pool-1-thread-2：线程名称_thread_in_native：当前线程状态。该描述还包含有： _thread_in_native：线程当前状态，状态枚举包括： _thread_uninitialized：线程还没有创建，它只在内存原因崩溃的时候才出现 _thread_new：线程已经被创建，但是还没有启动 _thread_in_native：线程正在执行本地代码，一般这种情况很可能是本地代码有问题 _thread_in_vm：线程正在执行虚拟机代码 _thread_in_Java：线程正在执行解释或者编译后的Java代码 _thread_blocked：线程处于阻塞状态 …_trans：以_trans结尾，线程正处于要切换到其它状态的中间状态 id=30111：线程IDstack(0x00007f3d567e5000,0x00007f3d568e6000)：栈区间 siginfo: si_signo: 11 (SIGSEGV), si_code: 1 (SEGV_MAPERR), si_addr: 0x0000000000000003

表示导致虚拟机终止的非预期的信号信息

Top of Stack: (sp=0x00007f3d568e2280) 0x00007f3d568e2280: b8e4bfb900000800 00007f3d568e3760 0x00007f3d568e2290: 00007f3d568e3758 00007f3d568e377c 0x00007f3d568e22a0: 00007f3d568e3778 6f6e6b6e56a88a58 0x00007f3d568e22b0: 00000100000149a0 7a68710800000000 0x00007f3d568e22c0: 6970067363642d78 6d6f63036e61676e ....省略 Instructions: (pc=0x0000003797807a91) 0x0000003797807a71: 48 89 45 b8 48 8b 4d b8 0f b6 51 03 89 d3 83 e3 0x0000003797807a81: 0f 75 0d 0f b7 49 06 66 c1 c9 08 66 85 c9 75 4f 0x0000003797807a91: 0f b6 48 03 bf 0f 00 00 00 40 20 cf 75 0d 0f b7 0x0000003797807aa1: 70 06 66 c1 ce 08 66 85 f6 75 34 83 e1 0f 83 e2

栈顶程序计数器旁的操作码，它们可以被反汇编成系统崩溃前执行的指令。

Stack: [0x00007f3d567e5000,0x00007f3d568e6000], sp=0x00007f3d568e2280, free space=1012k Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code) C [libresolv.so.2+0x7a91] __libc_res_nquery+0x1c1 C [libresolv.so.2+0x7fd1] Java frames: (J=compiled Java code, j=interpreted, Vv=VM code) J 15056 java.net.Inet6AddressImpl.lookupAllHostAddr(Ljava/lang/String;)[Ljava/net/InetAddress; (0 bytes) @ 0x00007f3d7492af8c [0x00007f3d7492af40+0x4c] J 14966 C1 java.net.InetAddress.getAddressesFromNameService(Ljava/lang/String;Ljava/net/InetAddress;)[Ljava/net/InetAddress; (245 bytes) @ 0x00007f3d75466754 [0x00007f3d754662c0+0x494] J 14291 C2 java.net.InetAddress.getAllByName(Ljava/lang/String;Ljava/net/InetAddress;)[Ljava/net/InetAddress; (387 bytes) @ 0x00007f3d7534b718 [0x00007f3d7534ae20+0x8f8] J 14178 C1 java.net.InetSocketAddress.<init>(Ljava/lang/String;I)V (47 bytes) @ 0x00007f3d752ce0f4 [0x00007f3d752cdec0+0x234] j sun.security.ssl.SSLSocketImpl.<init>(Lsun/security/ssl/SSLContextImpl;Ljava/lang/String;ILjava/net/InetAddress;I)V+144 j sun.security.ssl.SSLSocketFactoryImpl.createSocket(Ljava/lang/String;ILjava/net/InetAddress;I)Ljava/net/Socket;+13 j com.ufclub.daq.qhzx.utils.SSLProtocolSocketFactory.createSocket(Ljava/lang/String;ILjava/net/InetAddress;I)Ljava/net/Socket;+15 .... 省略代码

线程栈信息。包含了地址、栈顶、栈计数器和线程尚未使用的栈信息。到这里就基本上已经确定了问题所在原因了。

线程信息

Java Threads: ( => current thread ) 0x00007f3d5d0a0800 JavaThread "logback-8" daemon [_thread_blocked, id=489, stack(0x00007f3d56de7000,0x00007f3d56ee8000)] 0x00007f3d5d09f800 JavaThread "logback-7" daemon [_thread_blocked, id=30974, stack(0x00007f3d53fc3000,0x00007f3d540c4000)] 0x00007f3d5c47f800 JavaThread "logback-6" daemon [_thread_blocked, id=25662, stack(0x00007f3d545c9000,0x00007f3d546ca000)] 0x00007f3d5c2a4000 JavaThread "logback-5" daemon [_thread_blocked, id=20922, stack(0x00007f3d552d2000,0x00007f3d553d3000)] 0x0000000003291800 JavaThread "logback-4" daemon [_thread_blocked, id=16768, stack(0x00007f3d542c6000,0x00007f3d543c7000)] 0x0000000002320000 JavaThread "logback-3" daemon [_thread_blocked, id=14730, stack(0x00007f3d54bcd000,0x00007f3d54cce000)] 0x0000000002d05000 JavaThread "logback-2" daemon [_thread_blocked, id=6569, stack(0x00007f3d549cb000,0x00007f3d54acc000)]

所有线程信息，一目了然。_thread_blocked表示阻塞。

安全点和锁信息

VM state:not at safepoint (normal execution)

虚拟机状态。not at safepoint 表示正常运行。其余状态：

at safepoint：所有线程都因为虚拟机等待状态而阻塞，等待一个虚拟机操作完成；synchronizing：一个特殊的虚拟机操作，要求虚拟机内的其它线程保持等待状态。 VM Mutex/Monitor currently owned by a thread: None

虚拟机的 Mutex 和 Monito r目前没有被线程持有。Mutex 是虚拟机内部的锁，而 Monitor 则关联到了 Java 对象。

堆信息

Heap: PSYoungGen total 178688K, used 25522K [0x00000000eab00000, 0x00000000f8d80000, 0x0000000100000000) eden space 177664K, 13% used [0x00000000eab00000,0x00000000ec343d30,0x00000000f5880000) from space 1024K, 65% used [0x00000000f8c80000,0x00000000f8d28d20,0x00000000f8d80000) to space 1024K, 0% used [0x00000000f8b80000,0x00000000f8b80000,0x00000000f8c80000) ParOldGen total 360448K, used 47193K [0x00000000c0000000, 0x00000000d6000000, 0x00000000eab00000) object space 360448K, 13% used [0x00000000c0000000,0x00000000c2e16518,0x00000000d6000000) Metaspace used 79300K, capacity 80628K, committed 80936K, reserved 1120256K class space used 9401K, capacity 9645K, committed 9768K, reserved 1048576K Card table byte_map: [0x00007f3d729f1000,0x00007f3d72bf2000] byte_map_base: 0x00007f3d723f1000

新生代、老年代、元空间一目了然。

Card table表示一种卡表，是 jvm 维护的一种数据结构，用于记录更改对象时的引用，以便 gc 时遍历更少的 table 和 root。

本地代码缓存

CodeCache: size=245760Kb used=41374Kb max_used=41402Kb free=204385Kb bounds [0x00007f3d72fb2000, 0x00007f3d75872000, 0x00007f3d81fb2000] total_blobs=12767 nmethods=12130 adapters=549 compilation: enabled

一块用于编译和保存本地代码的内存。

编译事件

Compilation events (10 events): Event: 501041.566 Thread 0x0000000001b6e000 16334 3 sun.security.rsa.RSAKeyFactory::<init> (5 bytes) Event: 501041.566 Thread 0x0000000001b6e000 nmethod 16334 0x00007f3d74985790 code [0x00007f3d74985900, 0x00007f3d74985b10] Event: 501041.569 Thread 0x0000000001b6e000 16335 3 sun.security.pkcs.PKCS8Key::<init> (5 bytes) Event: 501041.570 Thread 0x0000000001b6e000 nmethod 16335 0x00007f3d74736290 code [0x00007f3d74736400, 0x00007f3d747365b0] Event: 501041.575 Thread 0x0000000001b6e000 16336 3 sun.security.ssl.BaseSSLSocketImpl::<init> (15 bytes) Event: 501041.576 Thread 0x0000000001b6e000 nmethod 16336 0x00007f3d73f9b450 code [0x00007f3d73f9b5c0, 0x00007f3d73f9b7e8] Event: 501041.578 Thread 0x0000000001b6e000 16337 3 javax.net.ssl.SSLSocket::<init> (5 bytes) Event: 501041.580 Thread 0x0000000001b6e000 nmethod 16337 0x00007f3d739c7210 code [0x00007f3d739c7380, 0x00007f3d739c7508] Event: 501041.582 Thread 0x0000000001b6e000 16338 3 javax.net.ssl.SNIServerName::<init> (66 bytes) Event: 501041.583 Thread 0x0000000001b6e000 nmethod 16338 0x00007f3d74c15cd0 code [0x00007f3d74c15ea0, 0x00007f3d74c164f8]

记录10次编译事件。这里的信息也印证了上面的结论。

gc 日志

GC Heap History (10 events): Event: 476166.948 GC heap before {Heap before GC invocations=149 (full 3): PSYoungGen total 194560K, used 193984K [0x00000000eab00000, 0x00000000f8e80000, 0x0000000100000000) eden space 193536K, 100% used [0x00000000eab00000,0x00000000f6800000,0x00000000f6800000) from space 1024K, 43% used [0x00000000f8c80000,0x00000000f8cf0000,0x00000000f8d80000) to space 1024K, 0% used [0x00000000f8d80000,0x00000000f8d80000,0x00000000f8e80000) ParOldGen total 360448K, used 47161K [0x00000000c0000000, 0x00000000d6000000, 0x00000000eab00000) object space 360448K, 13% used [0x00000000c0000000,0x00000000c2e0e518,0x00000000d6000000) Metaspace used 79243K, capacity 80500K, committed 80680K, reserved 1120256K class space used 9400K, capacity 9645K, committed 9768K, reserved 1048576K Event: 476166.985 GC heap after Heap after GC invocations=149 (full 3): PSYoungGen total 190464K, used 448K [0x00000000eab00000, 0x00000000f8e00000, 0x0000000100000000) eden space 189952K, 0% used [0x00000000eab00000,0x00000000eab00000,0x00000000f6480000) from space 512K, 87% used [0x00000000f8d80000,0x00000000f8df0000,0x00000000f8e00000) to space 1024K, 0% used [0x00000000f8c00000,0x00000000f8c00000,0x00000000f8d00000) ParOldGen total 360448K, used 47161K [0x00000000c0000000, 0x00000000d6000000, 0x00000000eab00000) object space 360448K, 13% used [0x00000000c0000000,0x00000000c2e0e518,0x00000000d6000000) Metaspace used 79243K, capacity 80500K, committed 80680K, reserved 1120256K class space used 9400K, capacity 9645K, committed 9768K, reserved 1048576K } ... 省略

同样是记录10次 GC。

jvm 内存映射

Dynamic libraries: 00400000-00401000 r-xp 00000000 fd:00 2108521 /usr/java/jdk1.8.0_45/bin/java 00600000-00601000 rw-p 00000000 fd:00 2108521 /usr/java/jdk1.8.0_45/bin/java 019e9000-04f5e000 rw-p 00000000 00:00 0 [heap] c0000000-d6000000 rw-p 00000000 00:00 0 d6000000-eab00000 ---p 00000000 00:00 0 ... 7f3d6df48000-7f3d6df6a000 r--s 0038e000 fd:00 2108900 /usr/java/jdk1.8.0_45/jre/lib/ext/cldrdata.jar 7f3d6df6a000-7f3d6df73000 r--s 07db3000 fd:00 2374798 /opt/risk/service/xxx-xxx-container/xxx-xxxx-container.jar ...

这些信息是虚拟机崩溃时的虚拟内存列表区域。它可以告诉你崩溃原因时哪些类库正在被使用，位置在哪里，还有堆栈和守护页信息。

00400000-00401000：内存区域r-xp：权限，r/w/x/p/s分别表示读/写/执行/私有/共享00000000：文件内的偏移量fd:00：文件位置的majorID和minorID2108521：索引节点号/usr/java/jdk1.8.0_45/bin/java：文件位置 从/opt/risk/service/xxx-xxx-container/xxx-xxxx-container.jar我们可以确认是那个jar出问题了。

jvm 启动参数

VM Arguments: jvm_args: -Xmx1024M -Xms512M -XX:PermSize=128M -XX:MaxPermSize=256M java_command: /opt/risk/service/xxx-xxx-xxx-container/xxx-xxx-xxx-container.jar java_class_path (initial): /opt/risk/service/xxx-xxx-xxx-container/xxx-xxx-xxx-container.jar Launcher Type: SUN_STANDARD Environment Variables: JAVA_HOME=/usr/java/jdk1.8.0_45 CLASSPATH=.:/usr/java/jdk1.8.0_45/lib/dt.jar:/usr/java/jdk1.8.0_45/lib/tools.jar PATH=/usr/java/jdk1.8.0_45/bin:/bin:/usr/local/erlang/bin:/usr/local/maven3/bin:/usr/local/git/bin:/usr/java/jdk1.8.0_45/bin:/bin:/usr/local/erlang/bin:/usr/local/maven3/bin:/usr/local/git/bin:/usr/lib64/qt-3.3/bin:/usr/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/root/bin SHELL=/bin/bash

jvm 虚拟机参数和环境变量。

参考资料

JVM致命错误日志（hs_err_pid.log）解读JVM致命错误日志(hs_err_pid.log)分析