weblogic jvm -Dsun.zip.disableMemoryMapping=true

秒速五厘米 2022-08-08 17:55 6阅读 0赞

weblogic 12c的环境，通过管理服务看到此节点状态为unkown，分析日志，结论是：JVM crash了，需要加上参数

\-Dsun.zip.disableMemoryMapping=true

原因是

1. While a class is in use it is dynamically reloaded from a jar file. 动态加载了jar文件
    2. While a jar file is being accessed by the class loader, the jar file is being modified. 当访问jar文件时,修改了jar
    3. A Jarfile which was bigger than 4GB was accessed (applies to Java 6 and earlier only)  jar文件非常大，超过4G

**   在nohup.out日志看到内容:**  
\# An error report file with more information is saved as:  
\# /data/wls1212/user\_projects/domains/\_domain/hs\_err\_pid8027.log  
\#  
\# If you would like to submit a bug report, please visit:  
\#   ![Image 1][]http://bugreport.sun.com/bugreport/crash.jsp  
\# The crash happened outside the Java Virtual Machine in native code.  
\# See problematic frame for where to report the bug.  
\#  
/data/wls1212/user\_projects/domains/domain/bin/startWebLogic.sh: line 195:  8027 已放弃                  (core dumped) $\{JAVA\_HOME\}/bin/java $\{JAVA\_VM\} $\{MEM\_ARGS\} -Dweblogic.Name=$\{SERVER\_NAME\} -Djava.security.policy=$\{WLS\_POLICY\_FILE\} $\{JAVA\_OPTIONS\} $\{PROXY\_SETTINGS\} $\{SERVER\_CLASS\}

**  hs\_err\_pid8027.log的内容：**

Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)  
C  \[libc.so.6+0x89aab\]  memcpy+0x15b  
C  \[libzip.so+0x50b0\]  ZIP\_GetEntry+0xd0  
C  \[libzip.so+0x3eed\]  Java\_java\_util\_zip\_ZipFile\_getEntry+0xad  
J 117  java.util.zip.ZipFile.getEntry(J\[BZ)J (0 bytes) @ 0x00007f580109f1ee \[0x00007f580109f120+0xce\]

Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)  
J 117  java.util.zip.ZipFile.getEntry(J\[BZ)J (0 bytes) @ 0x00007f580109f178 \[0x00007f580109f120+0x58\]  
J 119 C2 java.util.jar.JarFile.getEntry(Ljava/lang/String;)Ljava/util/zip/ZipEntry; (22 bytes) @ 0x00007f58010a3ee8 \[0x00007f58010a3e20+0xc8\]  
J 1078 C2 weblogic.utils.classloaders.ZipClassFinder.getSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; (84 bytes) @ 0x00007f58012be9a4 \[0x00007f58012be860+0x144\]  
J 1334 C2 weblogic.utils.classloaders.MultiClassFinder.getSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; (49 bytes) @ 0x00007f580132ee60 \[0x00007f580132ed00+0x160\]  
J 1334 C2 weblogic.utils.classloaders.MultiClassFinder.getSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; (49 bytes) @ 0x00007f580132ef18 \[0x00007f580132ed00+0x218\]  
J 1334 C2 weblogic.utils.classloaders.MultiClassFinder.getSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; (49 bytes) @ 0x00007f580132ef18 \[0x00007f580132ed00+0x218\]  
J 2020 C2 weblogic.application.utils.CompositeWebAppFinder.getSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; (31 bytes) @ 0x00007f58016a5ef0 \[0x00007f58016a5ea0+0x50\]  
J 1334 C2 weblogic.utils.classloaders.MultiClassFinder.getSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; (49 bytes) @ 0x00007f580132ef18 \[0x00007f580132ed00+0x218\]  
J 1334 C2 weblogic.utils.classloaders.MultiClassFinder.getSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; (49 bytes) @ 0x00007f580132ef18 \[0x00007f580132ed00+0x218\]  
J 4834 C2 weblogic.utils.classloaders.GenericClassLoader.findResource(Ljava/lang/String;)Ljava/net/URL; (100 bytes) @ 0x00007f5802018428 \[0x00007f5802017fa0+0x488\]  
J 6887 C2 weblogic.utils.classloaders.GenericClassLoader.getResourceInternal(Ljava/lang/String;)Ljava/net/URL; (145 bytes) @ 0x00007f5801a92660 \[0x00007f5801a92580+0xe0\]  
J 2507 C2 weblogic.utils.classloaders.ChangeAwareClassLoader.getResource(Ljava/lang/String;)Ljava/net/URL; (77 bytes) @ 0x00007f5801895b48 \[0x00007f5801895b00+0x48\]

官方的解析：

<table> 
 <tbody> 
  <tr> 
   <td align="left"><span style="font-size:14px; text-align:right; padding:0px 6px 0px 0px; font-weight:bold">Java Virtual Machine (JVM) crashes in java.util.zip.ZipFile.getEntry() during Class Loading (文档 ID 1296729.1)</span></td> 
   <td align="right"><a title="转到底部" href="https://support.oracle.com/epmos/faces/SearchDocDisplay?_adf.ctrl-state=1da5bbqnzg_9&amp;_afrLoop=424858884619851#" style="font-size:11px; white-space:nowrap; text-decoration:none" rel="nofollow"><img src="https://support.oracle.com/epmos/ui/images/quicklink_smlarrowdown_enabled.gif" title="转到底部" alt="转到底部" style="border:none; vertical-align:middle; display:inline"><span style="color:rgb(0,50,134); margin-left:3px">转到底部</span></a></td> 
   <td><img src="/images/20220731/440ecac94035450699b78f2b921eb58f.png" alt="" width="20" height="10"></td> 
  </tr> 
 </tbody> 
</table>

--------------------

![t.gif][]

<table style="table-layout:fixed; overflow:hidden"> 
 <tbody> 
  <tr> 
   <td style="overflow:hidden; vertical-align:top"> 
    <div style="overflow:auto"> 
     <span style="font-size:12px"></span> 
     <p><strong>In this Document</strong><br> </p> 
     <table> 
      <tbody> 
       <tr> 
        <td></td> 
        <td><a href="https://support.oracle.com/epmos/faces/SearchDocDisplay?_adf.ctrl-state=1da5bbqnzg_9&amp;_afrLoop=424858884619851#SYMPTOM" rel="nofollow">Symptoms</a></td> 
       </tr> 
      </tbody> 
     </table> 
     <table> 
      <tbody> 
       <tr> 
        <td>&nbsp;</td> 
        <td><a href="https://support.oracle.com/epmos/faces/SearchDocDisplay?_adf.ctrl-state=1da5bbqnzg_9&amp;_afrLoop=424858884619851#CAUSE" rel="nofollow">Cause</a></td> 
       </tr> 
      </tbody> 
     </table> 
     <table> 
      <tbody> 
       <tr> 
        <td>&nbsp;</td> 
        <td><a href="https://support.oracle.com/epmos/faces/SearchDocDisplay?_adf.ctrl-state=1da5bbqnzg_9&amp;_afrLoop=424858884619851#FIX" rel="nofollow">Solution</a></td> 
       </tr> 
      </tbody> 
     </table> 
     <hr> 
     <p><br> </p> 
     <h2 style="border-bottom-width:1px; border-bottom-style:solid; border-bottom-color:rgb(196,209,230); font-size:16px; background-color:rgb(119,119,115); color:rgb(255,255,255); text-transform:uppercase; padding-top:6px; padding-bottom:6px; padding-left:8px"> APPLIES TO:</h2> Java Platform, Standard Edition - Version 1.4.2 and later 
     <br> Oracle WebLogic Server - Version 12.1.3.0.0 to 12.1.3.0.0 [Release 12c] 
     <br> Information in this document applies to any platform. 
     <br> 
     <h2 style="border-bottom-width:1px; border-bottom-style:solid; border-bottom-color:rgb(196,209,230); font-size:16px; background-color:rgb(119,119,115); color:rgb(255,255,255); text-transform:uppercase; padding-top:6px; padding-bottom:6px; padding-left:8px"> <a rel="nofollow"></a>SYMPTOMS</h2> 
     <p>Random crashes during classloading while a jar/zip file is being accessed.&nbsp; Here is a typical stack trace. Please notice that a custom classloader calls java.util.zip.ZipFile.getEntry() and the crash happens somewhere in libzip or libc or a native windows dll:<br> <br> <span style="font-family:'Courier New',Courier,monospace"><br> </span></p> 
     <div style="overflow:auto; border:1px solid rgb(196,209,230); padding:0.5em; margin:5px 0px 0px; font-family:'Courier New',Courier,monospace; font-size:12px; background-color:rgb(224,234,241); width:712.5px"> 
      <span><span>Stack: [0xfffffffe4e900000,0xfffffffe4e940000], sp=0xfffffffe4e93b1a0, free space=236k<br> Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)<br> </span></span> 
      <blockquote>
        C [libc_psr.so.1+0xbf4] 
       <br> C [libzip.so+0xe280] 
       <br> C [libzip.so+0x28e8] 
       <br> C [libzip.so+0x2d9c] 
       <br> J java.util.zip.ZipFile.getEntry(JLjava/lang/String;Z)J 
       <br> J java.util.zip.ZipFile.getEntry(Ljava/lang/String;)Ljava/util/zip/ZipEntry; 
       <br> J weblogic.utils.classloaders.JarClassFinder.getSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; 
       <br> J weblogic.utils.classloaders.AbstractClassFinder.getClassSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; 
       <br> J weblogic.utils.classloaders.MultiClassFinder.getClassSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; 
       <br> J weblogic.utils.classloaders.MultiClassFinder.getClassSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; 
       <br> J weblogic.utils.classloaders.MultiClassFinder.getClassSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; 
       <br> j weblogic.application.utils.CompositeWebAppFinder.getClassSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source;+5 
       <br> J weblogic.utils.classloaders.MultiClassFinder.getClassSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; 
       <br> J weblogic.utils.classloaders.MultiClassFinder.getClassSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source; 
       <br> j weblogic.utils.classloaders.CodeGenClassFinder.getClassSource(Ljava/lang/String;)Lweblogic/utils/classloaders/Source;+43 
       <br> j weblogic.utils.classloaders.GenericClassLoader.findLocalClass(Ljava/lang/String;)Ljava/lang/Class;+87 
       <br> j weblogic.utils.classloaders.GenericClassLoader.findClass(Ljava/lang/String;)Ljava/lang/Class;+117 
       <br> j weblogic.utils.classloaders.ChangeAwareClassLoader.findClass(Ljava/lang/String;)Ljava/lang/Class;+60 
       <br> J java.lang.ClassLoader.loadClass(Ljava/lang/String;Z)Ljava/lang/Class; 
       <br> J weblogic.utils.classloaders.ChangeAwareClassLoader.loadClass(Ljava/lang/String;)Ljava/lang/Class; 
       <br> j java.lang.ClassLoader.loadClassInternal(Ljava/lang/String;)Ljava/lang/Class;+2 
      </blockquote> 
     </div> 
     <p>&nbsp;</p> 
     <h2 style="border-bottom-width:1px; border-bottom-style:solid; border-bottom-color:rgb(196,209,230); font-size:16px; background-color:rgb(119,119,115); color:rgb(255,255,255); text-transform:uppercase; padding-top:6px; padding-bottom:6px; padding-left:8px"> <a rel="nofollow"></a>CAUSE</h2> 
     <pre>There are three possible scenarios here:

1. While a class is in use it is dynamically reloaded from a jar file.
2. While a jar file is being accessed by the class loader, the jar file is being modified.
3. A Jarfile which was bigger than 4GB was accessed (applies to Java 6 and earlier only)

None of the above are Java bugs. It's the application's responsibility to prevent this from happening.
A crash is unavoidable if a Jarfile is being modified while it's in use. It's similar to modifying a shared 
library or dll while a program is running. This will also lead to an application crash.</pre> 
     <p>Please note that a crash may happen even a long time after a jarfile was modified as classloaders keep references to jarfiles.</p> 
     <p>Another possible sceanrio is when Java or the application itself is being patched while the application is running.</p> 
     <p>Java 6 and earlier have a imitation that only Jarfiles less than 4GB can be accessed. See also: https://bugs.openjdk.java.net/browse/JDK-4681995</p> 
     <p>&nbsp;</p> 
     <p>&nbsp;</p> 
     <h2 style="border-bottom-width:1px; border-bottom-style:solid; border-bottom-color:rgb(196,209,230); font-size:16px; background-color:rgb(119,119,115); color:rgb(255,255,255); text-transform:uppercase; padding-top:6px; padding-bottom:6px; padding-left:8px"> <a rel="nofollow"></a>SOLUTION</h2> 
     <p><br> Make sure the application code does not reload a class while it's in use.&nbsp; In addition, make sure that a jar file is not being updated while it's being accessed by the class loader.<br> <br> <br> Starting with 6u21-rev-b09 (non-public build) and 6u23 (public) there is a new property<br> <br> -Dsun.zip.disableMemoryMapping=true<br> <br> which can be used to work around this problem. However, this should not serve as an excuse to not fix the misbehaving application. Overwriting and/or modifying a file that is still in use remains an application side bug.</p> 
     <p>See also:&nbsp;<a href="http://www.oracle.com/us/technologies/java/overview-156328.html" rel="nofollow">http://www.oracle.com/us/technologies/java/overview-156328.html</a>&nbsp;. Look for "Disabling&nbsp;<code>mmap</code>&nbsp;Usage (on Solaris or Linux)"<br> <br> </p> 
     <p><a href="http://www.oracle.com/us/technologies/java/overview-156328.html" rel="nofollow">http://www.oracle.com/us/technologies/java/overview-156328.html</a>&nbsp;的内容：<br> </p> 
     <p></p> 
     <p><strong>Disabling&nbsp;<span style="color:#666666">mmap</span>&nbsp;Usage (on Solaris or Linux)</strong></p> 
     <p>Thisrelease includes a new system property,&nbsp;<span style="color:#666666">sun.zip.disableMemoryMapping</span>, which allows the user to disable the&nbsp;<span style="color:#666666">mmap</span>&nbsp;<span style="background:white">usage in Sun's</span>&nbsp;<span style="color:#666666">java.util.zip.Zipfile</span>&nbsp;<span style="background:white">implementation (onSolaris and Linux platforms). Solaris or Linux applications that use</span>&nbsp;<span style="color:#666666">java.util.zip.ZipFile</span>&nbsp;<span style="background:white">may experience a</span>&nbsp;<span style="color:#666666">SIGBUS</span>&nbsp;<span style="background:white">VM crash if the application accidentally overwritesany zip or jar files that are still being used by the same Java runtime.Although this is a programming error of the offending application, this systemproperty provides a solution to avoid the VM crash. With the property set totrue (</span><span style="color:#666666">-Dsun.zip.disableMemoryMapping=true</span>, or simply&nbsp;<span style="color:#666666">-Dsun.zip.disableMemoryMapping</span>) the Sun JDK/JRE runtime disables the&nbsp;<span style="color:#666666">mmap</span>&nbsp;<span style="background:white">usage and the VM crash that might otherwise occur byoverwriting the jar or zip file can be avoided.</span></p> 
     <br> 
     <p><br> </p> 
    </div> </td> 
  </tr> 
 </tbody> 
</table>

[Image 1]: 
[t.gif]: /images/20220731/440ecac94035450699b78f2b921eb58f.png