weblogic在linux下启动会卡住的问题解决

超、凢脫俗 2022-07-24 10:28 263阅读 0赞

启动weblogic 11g的时候实例会无缘无故卡住，完全不知道原因，最好查到是要改一下JDK的一个参数：  
    修改  
    $JAVA\_HOME/jre/lib/security/java.security  
    修改securerandom.source=file:/dev/./urandom

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   <td align="left"><a title="单击此项可添加到收藏夹" href="https://support.oracle.com/epmos/faces/SearchDocDisplay?_adf.ctrl-state=7j2vf7imi_82&amp;_afrLoop=532608576663340#" style="font-size:11px; white-space:nowrap; text-decoration:none" rel="nofollow"><img src="https://support.oracle.com/epmos/common/images/favorites_qualifier_notsel.png" title="单击此项可添加到收藏夹" alt="单击此项可添加到收藏夹" style="border:none; vertical-align:middle; display:inline"></a><span><span></span></span><span></span></td> 
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   <td align="left"><span style="font-size:14px; text-align:right; padding:0px 6px 0px 0px; font-weight:bold">How to Diagnose a Linux Entropy Issue on WebLogic Server Instances (文档 ID 1574979.1)</span></td> 
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     <p><strong>In this Document</strong><br> </p> 
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        <td><a href="https://support.oracle.com/epmos/faces/SearchDocDisplay?_adf.ctrl-state=7j2vf7imi_82&amp;_afrLoop=532608576663340#SYMPTOM" rel="nofollow">Symptoms</a></td> 
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        <td>&nbsp;</td> 
        <td><a href="https://support.oracle.com/epmos/faces/SearchDocDisplay?_adf.ctrl-state=7j2vf7imi_82&amp;_afrLoop=532608576663340#CAUSE" rel="nofollow">Cause</a></td> 
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        <td><a href="https://support.oracle.com/epmos/faces/SearchDocDisplay?_adf.ctrl-state=7j2vf7imi_82&amp;_afrLoop=532608576663340#FIX" rel="nofollow">Solution</a></td> 
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        <td>&nbsp;</td> 
        <td><a href="https://support.oracle.com/epmos/faces/SearchDocDisplay?_adf.ctrl-state=7j2vf7imi_82&amp;_afrLoop=532608576663340#REF" rel="nofollow">References</a></td> 
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     <hr> 
     <p></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> Oracle SOA Suite - Version 11.1.1.1.0 and later 
     <br> Oracle HTTP Server - Version 12.1.3.0.0 and later 
     <br> Oracle WebLogic Server - Version 8.1 and later 
     <br> Linux x86 
     <br> Linux x86-64 
     <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>It is observed on some Linux boxes that WebLogic server startup takes several minutes and hangs for a while. Similar behavior&nbsp;<a href="http://download.oracle.com/docs/cd/E12839_01/relnotes.1111/e10133/weblogic_server_issues.htm#CIHIIBGJ" rel="nofollow">happens</a>&nbsp;during the domain creation, when the security information gets populated.</p> 
     <p>If you take a thread dump on the troubled process you will observe that WebLogic is waiting for random data generation since the OS is running out of entropy.</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)">
       - locked &lt;0x00000000e061f4b8&gt; (a java.lang.Object) 
      <br> at&nbsp; 
      <strong>sun.security.provider.NativePRNG$RandomIO.access$300(NativePRNG.java:108)</strong> 
      <br> at sun.security.provider.NativePRNG.engineGenerateSeed(NativePRNG.java:102) 
      <br> 
      <strong>at java.security.SecureRandom.generateSeed(SecureRandom.java:495)</strong> 
      <br> at com.bea.security.utils.random.AbstractRandomData.ensureInittedAndSeeded(AbstractRandomData.java:91) 
      <br> - locked &lt;0x00000000f8c7d7b8&gt; (a com.bea.security.utils.random.SecureRandomData) 
      <br> at&nbsp; 
      <strong>com.bea.security.utils.random.AbstractRandomData.getRandomBytes(AbstractRandomData.java:105)</strong> 
      <br> - locked &lt;0x00000000f8c7d7b8&gt; (a com.bea.security.utils.random.SecureRandomData) 
      <br> at&nbsp; 
      <strong>com.bea.security.utils.random.AbstractRandomData.getRandomBytes(AbstractRandomData.java:100)</strong> 
      <br> at com.bea.console.utils.CSRFUtils.getSecret(CSRFUtils.java:56) 
      <br> at jsp_servlet._jsp._changemgmt.__changemanager._jspService(__changemanager.java:156) 
     </div> 
     <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> 
     <p>According to the&nbsp;<a href="http://www.tldp.org/HOWTO/Security-HOWTO/kernel-security.html#AEN806" rel="nofollow">official Kernel documentation</a>, Linux has two devices to provide random data at any time:<strong>/dev/random</strong>&nbsp;and&nbsp;<strong>/dev/urandom</strong>. Both ways should be secure enough to use them in generating PGP keys, ssh challenges, and other applications where secure random numbers are required. Starting on kernel 2.6, default entropy is 4096 bits and problem arises when the entropy available on the system is minimum (around 100 bits or less).</p> 
     <p>The main difference between those two devices is that&nbsp;<strong>/dev/random runs out of random bits and makes you wait for more to be accumulated</strong>. Note that on some systems, it can block for a long time waiting for new user-generated entropy to be entered into the system.&nbsp;<br> <br> In terms of the outcome,<strong>&nbsp;/dev/random</strong>&nbsp;is categorized as a high quality entropy device if we compare it with&nbsp;<strong>/dev/urandom</strong>. The latter uses the entropy pool as long as it is available, but falls back on pseudo random numeric algorithms when depleted.</p> 
     <p><strong>Why a system could be running out of entropy?</strong></p> 
     <p>You have to consider that an Operating System performs cryptographic operations frequently (on ssh challenges, https connections, etc.) so the&nbsp;<strong>/dev/random</strong>&nbsp;pool gets consumed quite quickly. OS also expects to feed that pool with I/O operations coming from disk, network, mouse or keyboard but that situation does not happen as quickly. This is a common pattern on virtualized environments or headless boxes.</p> 
     <p>Is important to mention that&nbsp;<strong>Java uses /dev/random by default&nbsp;</strong>as entropy generator device.</p> 
     <p><strong>How to verify if you are encountering this issue?</strong></p> 
     <ol> 
      <li>Check the default system entropy.<br> 
       <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)">
         $ cat /proc/sys/kernel/random/poolsize&nbsp; 
        <br> 4096 
       </div> </li> 
      <li>Check the available entropy.<br> 
       <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)">
         $ cat /proc/sys/kernel/random/entropy_avail&nbsp; 
        <br> 125 
       </div> On previous example, entropy is too low.</li> 
      <li>Monitor the current entropy of the system by using the following command:<br> 
       <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)">
         $ for i in $(seq 500); do cat /proc/sys/kernel/random/entropy_avail ; sleep 5; done 
       </div> </li> 
      <li>Start a WebLogic server instance. You should see that entropy decreases or stalls.</li> 
     </ol> 
     <p>The following links explain in detail how Entropy affects Java on Linux Environments: bug&nbsp;<a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6202721" rel="nofollow">6202721</a>&nbsp;and<a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6521844" rel="nofollow">6521844</a>.</p> 
     <h2 style="border-bottom-width:1px; border-bottom-style:solid; border-bottom-color:rgb(196,209,230); font-size:16px; background-color:rgb(119,119,115); color:rgb(255,255,255); text-transform:uppercase; padding-top:6px; padding-bottom:6px; padding-left:8px"> <a rel="nofollow"></a>SOLUTION</h2> 
     <p>Choose one of the following approaches.<br> <br> 1. Feed the /dev/random device with additional I/O operations or using a random number generator tool (like<strong>rngd</strong>).<br> <br> 2. Instruct WebLogic server to use a non-blocking entropy device.</p> 
     <p>2.1 Long term solution</p> 
     <p><em>a) WebLogic Server Scope</em></p> 
     <p>i.&nbsp;&nbsp; Edit the Weblogic startup script (<strong>$DOMAIN_HOME/bin/startWebLogic.sh</strong>)<br> ii.&nbsp; Add the following to the JAVA_OPTIONS variable:&nbsp;<span style="font-family:'Courier New',Courier,monospace"><strong>-Djava.security.egd=file:/dev/./urandom</strong></span><br> iii. Save the file.<br> iv. Set the domain environment. ($DOMAIN_HOME/bin/setDomainEnv.sh)<br> v.&nbsp; Start WebLogic instances.</p> 
     <p><em>b) JDK Scope</em><br> <br> i.&nbsp;&nbsp; Edit the Java Security Properties file (<strong>$JAVA_HOME/jre/lib/security/java.security</strong>)<br> ii.&nbsp; The&nbsp;<strong>securerandom.source</strong>&nbsp;property specifies the source of seed data for secure random. If that property points to&nbsp;<strong>/dev/random</strong>, set it as one of the options listed below.<br> <span style="font-family:'Courier New',Courier,monospace"><strong>securerandom.source=file:/dev/./urandom</strong></span></p> 
     <p><span style="font-family:'Courier New',Courier,monospace"><strong>securerandom.source=file:/dev/urandom</strong></span></p> 
     <p>iii.&nbsp; Save changes and start the WebLogic Server instances.</p> 
     <p>2.2 Temporary solution (usually applied for testing purposes)</p> 
     <p>i. Override the JAVA_OPTIONS environment variable before starting WebLogic Server via shell scripts.<br> <span style="font-family:'Courier New',Courier,monospace">$ export JAVA_OPTIONS="${JAVA_OPTIONS}&nbsp;<strong>-Djava.security.egd=file:/dev/./urandom</strong>"</span></p> 
     <p>ii. Start WebLogic instances.</p> 
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