My simple web-app sometimes crashes when navigating around the site, the error message I’ve gotten from the logs are found below. I have absolutely no idea of what is causing this and would be very thankful for any tips that’ll lead me in the right direction.
HTTP Status 500 - org.hibernate.exception.JDBCConnectionException: Cannot open connection
type Exception report
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)
root cause
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)
root cause
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)
I m using 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>
It looks like you are leaking connections big time. Are you closing your hibernate sessions when you are done with them?
You could also try and fiddle about with
hibernate.connection.release_mode, by default, this is set to auto and it will release the connection when you close the session. However, you also have the options here to useafter_transactionorafter_statement(its rather self explanatory when it will release the connections for each of the two :P).With that said though, you do need to find out where you leaks are 🙂