JDK8 中 oom: unable to create new native thread 无法生成dump文件?

Question

启动脚本如下

#!/bin/sh
nohup java -XX:+HeapDumpOnOutOfMemoryError -XX:+ExitOnOutOfMemoryError -XX:HeapDumpPath=./ -XX:+PrintGCDetails -Xloggc:./gc.log -Dfile.encoding=utf-8 -jar demoOOM-0.0.1-SNAPSHOT.jar >> system.log 2>&1 &
echo $! > project.pid
tail -f system.log

按理说来应该是要在当前路径下,生成dump文件,但实际未生成,控制台打印结果如下

线程:10087
线程:10088
线程:10089
2022-11-11 09:49:30.165 ERROR 2435502 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Handler dispatch failed; nested exception is java.lang.OutOfMemoryError: unable to create new native thread] with root cause

java.lang.OutOfMemoryError: unable to create new native thread
        at java.lang.Thread.start0(Native Method) [na:1.8.0_312]
        at java.lang.Thread.start(Thread.java:717) [na:1.8.0_312]
        at com.example.demooom.TestController.createOOM(TestController.java:29) ~[classes!/:0.0.1-SNAPSHOT]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_312]
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_312]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_312]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_312]
        at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-5.3.23.jar!/:5.3.23]
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.23.jar!/:5.3.23]

并未找到输出dump文件的提示,是否指定文件名也无效. 请问这个有可能是什么问题呢?

Answer 1

不生成原因

有人提过这个 bug。

The -XX:+HeapDumpOnOutOfMemoryError command-line option tells the HotSpot VM to generate a heap dump when an allocation from the Java heap or the permanent generation cannot be satisfied.

-XX:+HeapDumpOnOutOfMemoryError 含义是告诉 jvm，当无法满足来自堆或永久代的分配时的堆转储时，生成 dump 文件。

Allocation of a native thread is not from the heap or the permanent generation - hence failure to allocate one does not result in a heap dump. (There would be little point in dumping the heap as that is not what was exhausted.)

本机线程的分配不是来自堆或永久代， 因此分配失败不会导致堆转储。

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为什么 jvm 不去生成

来自于另外一个论坛的相同 bug。

There would be little point in dumping the heap as that is not what was exhausted.

他说生成堆存储没有什么意义，因为它并没有被用尽。

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能不能生成

最后，来自于一个问题 heapdumponoutofmemoryerror-not-creating-hprof。

结论是，针对 unable to create new native thread 这样的错误，看起来没有可以自动生成的方法。