Error connecting to the database.Communications link failure

[Harivardhan Pyaram‏]

Hi Marko,

Have you come across the following exception while using the tool?? Any advice as to how to debug it?

[2015-05-19 12:24:30.575] SEVERE: u: Exception                                                                                                           

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: 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.newInstance0(Native Method)                                                                                                                                                             

        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)                                                                                                                                      

        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)                                                                                                                              

        at java.lang.reflect.Constructor.newInstance(Constructor.java:526)                                                                                                                                                                   

        at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)                                                                                                                                                                              

        at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1137)                                                                                                                                                         

        at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:356)                                                                                                                                                                                   

        at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2504)                                                                                                                                                               

        at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2541)

        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2323)

        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:832)

        at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)

        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)

        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)

        at java.lang.reflect.Constructor.newInstance(Constructor.java:526)

        at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)

        at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:417)

        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)

        at com.dbsolo.a.u.w(Unknown Source)

        at com.dbsolo.a.u.ĉ(Unknown Source)

        at com.dbsolo.P.k.A(Unknown Source)

        at com.dbsolo.P.k.A(Unknown Source)

        at com.dbsolo.P.E.A.D(Unknown Source)

        at com.dbsolo.ui.MainApp.main(Unknown Source)

        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

        at java.lang.reflect.Method.invoke(Method.java:606)

        at com.exe4j.runtime.LauncherEngine.launch(Unknown Source)

        at com.install4j.runtime.launcher.Launcher.main(Unknown Source)

Caused by: java.net.ConnectException: Connection refused

        at java.net.PlainSocketImpl.socketConnect(Native Method)

        at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)

        at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)

        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)

        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)

        at java.net.Socket.connect(Socket.java:579)

        at java.net.Socket.connect(Socket.java:528)

        at java.net.Socket.<init>(Socket.java:425)

        at java.net.Socket.<init>(Socket.java:241)

        at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:258)

        at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:306)

        ... 24 more

[2015-05-19 12:24:30.577] SEVERE: MainApp: Error performing comparison: {0}

java.lang.Exception: Error connecting to the database.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 com.dbsolo.a.u.ĉ(Unknown Source)

        at com.dbsolo.P.k.A(Unknown Source)

        at com.dbsolo.P.k.A(Unknown Source)

        at com.dbsolo.P.E.A.D(Unknown Source)

        at com.dbsolo.ui.MainApp.main(Unknown Source)

        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)

        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

        at java.lang.reflect.Method.invoke(Method.java:606)

        at com.exe4j.runtime.LauncherEngine.launch(Unknown Source)

        at com.install4j.runtime.launcher.Launcher.main(Unknown Source)

Regards,

Harivardhan Pyaram

[DB Solo Admin‏]

Please see the answer to this question for possible explanations

http://stackoverflow.com/questions/2983248/com-mysql-jdbc-exceptions-jdbc4-communicationsexception-communications-link-fai

Marko