1

我正在开发一个使用 Tomcat 6 作为 Web 服务器的基于 Java 的 Web 应用程序。通常，我们有一个 MySQL 后端，但在少数情况下，我们需要使用 MS SQL 来为我们的客户提供服务。在执行我们对这些 MS SQL 实例之一的最新升级时，我在访问 Web 应用程序的某些页面时开始出现 java 内存不足错误。通常在返回较大的结果集时发生，但并非总是如此。

在与我的 PC 上的本地实例相同的 Web 应用程序设置中，我没有收到此错误，这让我相信这是一个环境问题。我在 Tomcat 6 配置中尝试了许多不同的 Java 设置，但没有解决问题。

环境是具有 4GB RAM 的 32 位机器。我已经为 Tomcat 6 配置了以下内容： -XX:MaxPermSize=512m -Xnoclassgc 初始内存池：1024 最大内存池：1024

我也尝试增加 MaxPermSize，但这会导致 Tomcat 无法启动。

同样，我尝试将 -Xms -Xmx 设置为每个 256m、每个 512m 等。

我的本地计算机是 64 位的，具有 4GB RAM。我已经为 Tomcat 6 配置了以下内容： -XX:MaxPermSize=512m -Xnoclassgc 初始内存池：1024 最大内存池：1024

这可能是新升级中的 SQL 语句的问题吗？我不相信这种情况，因为错误不会发生在我的本地实例上。我相信它与环境有关，但无法弄清楚问题所在。

有人有建议吗？

这是记录的错误：

2012-09-19 11:44:54,745 [ http-80-7] ERROR org.apache.jsp.siteManager.util.error_jsp: javax.servlet.ServletException: java.lang.OutOfMemoryError: unable to create new native thread
at org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:862)
at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:791)
at org.apache.jsp.doc.doc.index_jsp._jspService(index_jsp.java:1106)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at com.djinnsoft.jade.sitetree.Sitetree.forward(Sitetree.java:405)
at com.djinnsoft.jade.sitetree.Sitetree.forward(Sitetree.java:344)
at com.djinnsoft.jade.sitetree.RootServlet.service(RootServlet.java:124)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.springboard.ram.report.ReportSecurityFilter.doFilter(ReportSecurityFilter.java:70)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:555)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:861)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1584)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.OutOfMemoryError: unable to create new native thread
at java.lang.Thread.start0(Native Method)
at java.lang.Thread.start(Unknown Source)
at com.microsoft.sqlserver.jdbc.TimeoutTimer.start(Unknown Source)
at com.microsoft.sqlserver.jdbc.TDSCommand.startResponse(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.doExecuteStatement(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerStatement$StmtExecCmd.doExecute(Unknown Source)
at com.microsoft.sqlserver.jdbc.TDSCommand.execute(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeCommand(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeStatement(Unknown Source)
at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeQuery(Unknown Source)
at org.apache.tomcat.dbcp.dbcp.DelegatingStatement.executeQuery(DelegatingStatement.java:208)
at org.apache.tomcat.dbcp.dbcp.DelegatingStatement.executeQuery(DelegatingStatement.java:208)
at com.djinnsoft.jade.data.record.SQLUtil.ExecuteQuery(SQLUtil.java:236)
at com.djinnsoft.jade.data.record.SQLUtil.ExecuteQuery(SQLUtil.java:207)
at com.djinnsoft.jade.data.record.RecordSource.find(RecordSource.java:184)
at com.djinnsoft.jade.data.record.RecordSource.find(RecordSource.java:148)
at com.djinnsoft.jade.content.data.DatabaseContentSource.createVersions(DatabaseContentSource.java:804)
at com.djinnsoft.jade.content.data.DatabaseContentSource.access$2900(DatabaseContentSource.java:42)
at com.djinnsoft.jade.content.data.DatabaseContentSource$8.process(DatabaseContentSource.java:747)
at com.djinnsoft.jade.data.record.SQLEnvironment.execute(SQLEnvironment.java:70)
at com.djinnsoft.jade.content.data.DatabaseContentSource.findImpl(DatabaseContentSource.java:672)
at com.djinnsoft.jade.content.GenericContentSource.findImpl(GenericContentSource.java:1077)
at com.djinnsoft.jade.content.GenericContentSource.find(GenericContentSource.java:1186)
at com.djinnsoft.jade.content.GenericContentSource.find(GenericContentSource.java:1200)
at com.djinnsoft.jade.content.GenericContentSource.find(GenericContentSource.java:1025)
at com.djinnsoft.jade.content.taglib.ContentBaseTag.findItem(ContentBaseTag.java:166)
at com.djinnsoft.jade.content.taglib.ContentTag.doStartTag(ContentTag.java:500)
at org.apache.jsp.doc.doc.index_jsp._jspx_meth_content_005faction_005f12(index_jsp.java:7637)
at org.apache.jsp.doc.doc.index_jsp._jspx_meth_c_005fforEach_005f6(index_jsp.java:6299)
at org.apache.jsp.doc.doc.index_jsp._jspx_meth_c_005fotherwise_005f3(index_jsp.java:4816)
at org.apache.jsp.doc.doc.index_jsp._jspx_meth_c_005fchoose_005f3(index_jsp.java:4395)
at org.apache.jsp.doc.doc.index_jsp._jspx_meth_c_005fotherwise_005f2(index_jsp.java:4363)
at org.apache.jsp.doc.doc.index_jsp._jspx_meth_c_005fchoose_005f2(index_jsp.java:4278)
at org.apache.jsp.doc.doc.index_jsp._jspx_meth_forms_005fpopulateResult_005f0(index_jsp.java:4244)
at org.apache.jsp.doc.doc.index_jsp._jspService(index_jsp.java:961)
... 32 more
4

2 回答 2

0

2012-09-19 11:44:54,745 [http-80-7] 错误 org.apache.jsp.siteManager.util.error_jsp: javax.servlet.ServletException: java.lang.OutOfMemoryError: 无法创建新的本地线程

这通常表明您在本机内存中而不是 Java 堆中获得了 OOM。这意味着操作系统无法分配线程。
这可能意味着：

  • 您运行的线程过多并且超出了某些操作系统限制（您使用的是 64 位机器，其线程限制与 32 位机器不同）或

  • 您的一个线程在初始化时使用了太多内存并崩溃（我无法更准确地描述这一点）。

您说您无法重现此内容，但这可能是因为您没有 Web 服务器的负载才能在本地重现此内容吗？我的意思是也许在部署的服务器实例中负载太重，并发请求太多（应用程序线程太多？），这导致了崩溃？

于 2012-09-19T17:26:05.600 回答
0

OK, so, I found the solution to the problem. In our new version of the web app, there is a context parameter that limits the display size of the results sets and paginates them at that limit. As I said earlier, this issue only seemed to be happening on larger result sets. The default setting for MySQL backends is 500, but apparently the MS SQL backend needs this to be set much lower. Setting it to 20 eliminated the out of memory errors. Thanks to all who offered advice. It was greatly appreciated.

于 2012-09-19T18:12:08.693 回答