java - com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException : Too many connections

Question

我的简单网络应用程序有时会在网站导航时崩溃，我从日志中得到的错误消息如下所示。我完全不知道是什么原因造成的，非常感谢任何能引导我朝着正确方向前进的提示。

HTTP Status 500 - org.hibernate.exception.JDBCConnectionException: Cannot open connection

类型异常报告

message org.hibernate.exception.JDBCConnectionException: Cannot open connection

description The server encountered an internal error that prevented it from fulfilling this request.

exception
org.apache.jasper.JasperException: org.hibernate.exception.JDBCConnectionException: Cannot open connection
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:549)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:470)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

根本原因

org.hibernate.exception.JDBCConnectionException: Cannot open connection
    org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:97)
    org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
    org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52)
    org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:449)
    org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161)
    org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1573)
    org.hibernate.loader.Loader.doQuery(Loader.java:696)
    org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
    org.hibernate.loader.Loader.doList(Loader.java:2228)
    org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)
    org.hibernate.loader.Loader.list(Loader.java:2120)
    org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:118)
    org.hibernate.impl.SessionImpl.list(SessionImpl.java:1596)
    org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:306)
    com.html.XmlSetting.getListOfhtml_connect(XmlSetting.java:55)
    com.html.XmlSetting.removeXml(XmlSetting.java:121)
    com.html.MarginSetting.removeXml(MarginSetting.java:291)
    org.apache.jsp.check_jsp._jspService(check_jsp.java:183)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

根本原因

com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Too many connections
    sun.reflect.GeneratedConstructorAccessor153.newInstance(Unknown Source)
    sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    java.lang.reflect.Constructor.newInstance(Constructor.java:532)
    com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.Util.getInstance(Util.java:381)
    com.mysql.jdbc.SQLError.createSQLException(SQLError.java:985)
    com.mysql.jdbc.SQLError.createSQLException(SQLError.java:957)
    com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3376)
    com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3308)
    com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:894)
    com.mysql.jdbc.MysqlIO.secureAuth411(MysqlIO.java:3808)
    com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1256)
    com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2032)
    com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:729)
    com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
    sun.reflect.GeneratedConstructorAccessor145.newInstance(Unknown Source)
    sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    java.lang.reflect.Constructor.newInstance(Constructor.java:532)
    com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
    com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:283)
    java.sql.DriverManager.getConnection(DriverManager.java:620)
    java.sql.DriverManager.getConnection(DriverManager.java:169)
    org.hibernate.connection.DriverManagerConnectionProvider.getConnection(DriverManagerConnectionProvider.java:133)
    org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
    org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:161)
    org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1573)
    org.hibernate.loader.Loader.doQuery(Loader.java:696)
    org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
    org.hibernate.loader.Loader.doList(Loader.java:2228)
    org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2125)
    org.hibernate.loader.Loader.list(Loader.java:2120)
    org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:118)
    org.hibernate.impl.SessionImpl.list(SessionImpl.java:1596)
    org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:306)
    com.html.XmlSetting.getListOfhtml_connect(XmlSetting.java:55)
    com.html.XmlSetting.removeXml(XmlSetting.java:121)
    com.html.MarginSetting.removeXml(MarginSetting.java:291)
    org.apache.jsp.check_jsp._jspService(check_jsp.java:183)
    org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

我正在使用 Apache Tomcat 7

hibernate .cfg.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>

        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/htmlcleaner</property>
        <property name="hibernate.connection.password">root</property>
        <property name="hibernate.connection.username">root</property>

        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="hibernate.connection.zeroDateTimeBehavior">convertToNull</property>

        <property name="connection.pool_size">1000</property>

       <!--  <property name="show_sql">true</property> -->
        <mapping class="com.model.html_connect"/>

    </session-factory>
</hibernate-configuration>

Answer 1

看起来你正在大量泄漏连接。您是否在完成 hibernate session 后关闭它们？

您也可以尝试摆弄 hibernate.connection.release_mode ，默认情况下，它设置为自动，它会在您关闭 session 时释放连接。但是，您也可以在此处选择使用 after_transaction 或 after_statement(当它将释放两者中的每一个的连接时，它相当不言自明 :P)。

尽管如此，您确实需要找出泄漏的位置:)