Help needed

[amirsydney]

Im getting the below error message with MySql connectivity. Please someone help me..

Note: My Java Program could connect to the database and function properly. It fetches data for the first time, after few tries I'm getting this error.

Below is the Error message:

com.mysql.jdbc.exceptions.jdbc4.CommunicationsExce ption: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at sun.reflect.NativeConstructorAccessorImpl.newInsta nce0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInsta nce(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newI nstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:40 9)
at com.mysql.jdbc.SQLError.createCommunicationsExcept ion(SQLError.java:1118)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:343)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(Co nnectionImpl.java:2308)
at com.mysql.jdbc.ConnectionImpl.createNewIO(Connecti onImpl.java:2122)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImp l.java:774)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connect ion.java:49)
at sun.reflect.NativeConstructorAccessorImpl.newInsta nce0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInsta nce(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newI nstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:40 9)
at com.mysql.jdbc.ConnectionImpl.getInstance(Connecti onImpl.java:375)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonReg isteringDriver.java:289)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at rbt.ResourceListMaker.getResource(ResourceListMake r.java:14)
at org.apache.jsp.Resource_jsp._jspService(Resource_j sp.java:95)
at org.apache.jasper.runtime.HttpJspBase.service(Http JspBase.java:98)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:729)
at org.apache.jasper.servlet.JspServletWrapper.servic e(JspServletWrapper.java:369)
at org.apache.jasper.servlet.JspServlet.serviceJspFil e(JspServlet.java:308)
at org.apache.jasper.servlet.JspServlet.service(JspSe rvlet.java:259)
at javax.servlet.http.HttpServlet.service(HttpServlet .java:729)
at org.apache.catalina.core.ApplicationFilterChain.in ternalDoFilter(ApplicationFilterChain.java:269)
at org.apache.catalina.core.ApplicationFilterChain.do Filter(ApplicationFilterChain.java:188)
at org.apache.catalina.core.StandardWrapperValve.invo ke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invo ke(StandardContextValve.java:172)
at org.apache.catalina.core.StandardHostValve.invoke( StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke (ErrorReportValve.java:117)
at org.apache.catalina.core.StandardEngineValve.invok e(StandardEngineValve.java:108)
at org.apache.catalina.connector.CoyoteAdapter.servic e(CoyoteAdapter.java:174)
at org.apache.coyote.http11.Http11Processor.process(H ttp11Processor.java:879)
at org.apache.coyote.http11.Http11BaseProtocol$Http11 ConnectionHandler.processConnection(Http11BaseProt ocol.java:665)
at org.apache.tomcat.util.net.PoolTcpEndpoint.process Socket(PoolTcpEndpoint.java:528)
at org.apache.tomcat.util.net.LeaderFollowerWorkerThr ead.runIt(LeaderFollowerWorkerThread.java:81)
at org.apache.tomcat.util.threads.ThreadPool$ControlR unnable.run(ThreadPool.java:689)
at java.lang.Thread.run(Unknown Source)
Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(Unknown Source)
at java.net.PlainSocketImpl.connectToAddress(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at com.mysql.jdbc.StandardSocketFactory.connect(Stand ardSocketFactory.java:256)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:292)
... 35 more
Exception: Communications link failure

[Tolls]

"No buffer space available (maximum connections reached?)"

Are you closing your connections?

[amirsydney]

I am closing the connection in a finally block as below:

finally {
try {
if(con != null)
con.close();
}
catch(SQLException e) {}
}

But still having this problem. Anything else to check?? Any suggestion appreciated...

[Tolls]

And you do that everywhere you use a connection?

i don't know if MySQL has a table you can look at to see the number of active connections.
If so you could monitor that.