users@glassfish.java.net

(GFv3) Communication link problem

From: <glassfish_at_javadesktop.org>
Date: Thu, 08 Apr 2010 10:27:00 PDT

Hi. Here is the problem:

I get a communication link failure while trying to connect to a DB (MySQL).
[#|2010-04-08T20:09:57.825+0300|SEVERE|glassfish3.0|javax.enterprise.system.std.com.sun.enterprise.v3.services.impl|_ThreadID=24;_ThreadName=Thread-1;|Cannot connect to database server = 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.|#]

Precisely at this string:
Statement s = conn.createStatement();
where conn is defined as follows:
private static java.sql.Connection conn;

For this app I have set a connection pool with default parameters and currently it (app) uses both JPA and direct JDBC queries. Recreation of connection pool gave nothing, ping just gave a message like next:
Ping Connection Pool for EsetPool is Failed. Ping failed Exce
 ption - Connection could not be allocated because: Communications lin
 k failure%%%EOL%%%%%%EOL%%%The last packet sent successfully to the s
 erver was 0 milliseconds ago. The driver has not received any packets
  from the server. Please check the server.log for more details.%%%EOL
 %%%Ping failed Exception - Connection could not be allocated because:
  Communications link failure

and flushing the connection pool gave:
com.sun.enterprise.admin.cli.CommandException: remote failure: Failed to flush connection pool ...

However I can connect to the database.

Any ideas on what's going on.
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