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java.sql.SQLException: Could not find database ID X name 'database'.

When I run all my JUnit tests, which uses a MS SQL Server database, I'm getting the following error:
java.sql.SQLException: Could not find database ID X, name 'database_name'. The database may be offline. Wait a few minutes and try again.
or sometimes the java.sql.Connection object is closed unexpectedly.

I got rid of the problem when I turned AUTO CLOSE setting to OFF, right after database creation:
CREATE DATABASE TEST123;
ALTER DATABASE [TEST123] SET AUTO_CLOSE OFF WITH NO_WAIT;
Check it out: Worst Practice: Allowing AutoClose on SQL Server Databases

Illegal attempt to create connection from another pool:

I have to extend one of the queries, to join with the table in another database, and possibly another server (linked).
Here are some domain facts, I can't change:
- Weblogic 10 used. EJB2 on the Java side
- Database driver is Non-XA. And we can't change that
- Both of the data sources are set as "Emulate 2 phase commit" transaction
option
- Query that is used is not directly in the business method called by the client, but somewhere in a private method, that is called at some point in the execution.
I am getting the following
java.sql.SQLException: Connection has already been created in this tx
context
for pool named dataSourceA.datasource. Illegal attempt to create
connection from another pool: dataSourceB.datasource
I only need to get the Database name and database host from the data source.
Exceptions comes, when I try to make connection to the data source dataSourceB.
Is there any way to get its properties without making a connection? Just to get String properties, database name and host?

MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up [duplicate]

This question already has answers here:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
(51 answers)
Closed 5 years ago.
I'm having trouble connecting to my database. I think there is a setting somewhere that I don't know about and needs to be changed. I have some really basic code here:
public static void main(String[] args)
{
try
{
Connection con = DriverManager.getConnection("jdbc:mysql://IP:3306/TABLENAME?autoReconnect=true","USERNAME", "PASSWORD");
con.close();
}
catch(Exception e)
{
e.printStackTrace();
}
}
Obviously with the login info. And it causes this error:
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Could not create connection to database server. Attempted reconnect 3 times. Giving up.
Caused by: 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.
Caused by: java.net.ConnectException: Connection refused
I've looked through about 10 different posts about the same problem and tried their solutions and still couldn't get it to work.

This problem occurs when the MySQL service is not running and you're trying to connect to the mysql database.
To resolve this in Windows,
Start >> type 'services' and open it.
Find the MySQL service. Probably with name MySQLxx. xx being the version.
eg. MySQL56, MySQL57 etc
Start the service and now try to connection to database.

Increase Mysql max connection,
SET GLOBAL max_connections = 1500;
If still getting an error then queries might be taking too long to respond.
In that case increase attempt while creating jdbc connection,
&maxReconnects=XX

You have to use database name instead of table name

Detect invalid credentials being passed to c3p0 connection pool

I'm writing a program that does some stuff on the database. Users are allowed to configure db processes, by passing db host port, type and credentials. It all works fine when values are correct. But when user passes invalid credentials I would like to show an error. So here is the part where I create my connection pool
ComboPooledDataSource cpds = new ComboPooledDataSource();
cpds.setJdbcUrl( connectionUrl );
cpds.setUser(username);
cpds.setPassword(password);
And later to verify if all is ok with the connection I do
cpds.getConnection()
I would expect to get some SQLException with vendor specific error saying that credentials are invalid (which happens when you use typical DriverManager way of getting the connection), but instead the process waits until a connection checkout exception is thrown
java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:118)
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:77)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:690)
....
Caused by: com.mchange.v2.resourcepool.TimeoutException: A client timed out while waiting to acquire a resource from com.mchange.v2.resourcepool.BasicResourcePool#20014b8 -- timeout at awaitAvailable()
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1467)
at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:644)
at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:554)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutAndMarkConnectionInUse(C3P0PooledConnectionPool.java:758)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:685)
... 66 more
How can I identify that there is a invalid credential issue with c3p0?

Your best way to validate provided credentials/JDBC params is to avoid connection pool at all.
Open dedicated connection just for this purpose and try to execute simplest SQL against new connection (eg SELECT 1 or similar).
After success, you can pass them to C3P0 otherwise propagate error back to user.

JDBC providers are free to create whatever error/exception messages they want. So you need to be ready to parse the error message of each provider in order to make sense of what is happening.
You can also try to get information from exception types if the JDBC provider segregates errors in separate types.
As a side note, giving too much information regarding why the connection failed may be considered a security breach. So one should not expect the JDBC driver to give you such information. For instance, why would any database collaborate with invasion attempts by saying "the username is correct, but the password is not."?

java.sql.Exception ClosedConnection

I am getting the following error:
java.sql.SQLException: Closed
Connection at
oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
at
oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:146)
at
oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:208)
at
oracle.jdbc.driver.PhysicalConnection.getMetaData(PhysicalConnection.java:1508)
at
com.ibatis.sqlmap.engine.execution.SqlExecutor.moveToNextResultsSafely(SqlExecutor.java:348)
at
com.ibatis.sqlmap.engine.execution.SqlExecutor.handleMultipleResults(SqlExecutor.java:320)
at
com.ibatis.sqlmap.engine.execution.SqlExecutor.executeQueryProcedure(SqlExecutor.java:277)
at
com.ibatis.sqlmap.engine.mapping.statement.ProcedureStatement.sqlExecuteQuery(ProcedureStatement.java:34)
at
com.ibatis.sqlmap.engine.mapping.statement.GeneralStatement.executeQueryWithCallback(GeneralStatement.java:173)
at
com.ibatis.sqlmap.engine.mapping.statement.GeneralStatement.executeQueryForList(GeneralStatement.java:123)
at
com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.queryForList(SqlMapExecutorDelegate.java:614)
at
com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.queryForList(SqlMapExecutorDelegate.java:588)
at
com.ibatis.sqlmap.engine.impl.SqlMapSessionImpl.queryForList(SqlMapSessionImpl.java:118)
at
org.springframework.orm.ibatis.SqlMapClientTemplate$3.doInSqlMapClient(SqlMapClientTemplate.java:268)
at
org.springframework.orm.ibatis.SqlMapClientTemplate.execute(SqlMapClientTemplate.java:193)
at
org.springframework.orm.ibatis.SqlMapClientTemplate.executeWithListResult(SqlMapClientTemplate.java:219)
at
org.springframework.orm.ibatis.SqlMapClientTemplate.queryForList(SqlMapClientTemplate.java:266)
at
gov.hud.pih.eiv.web.authentication.AuthenticationUserDAO.isPihUserDAO(AuthenticationUserDAO.java:24)
at
gov.hud.pih.eiv.web.authorization.AuthorizationProxy.isAuthorized(AuthorizationProxy.java:125)
at
gov.hud.pih.eiv.web.authorization.AuthorizationFilter.doFilter(AuthorizationFilter.java:224)
at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:246)
at
I am really stumped and can't figure out what could be causing this error. I am not able to reproduce the error on my machine but on production it is coming a lot of times. I am using iBatis in the whole application so there are no chances of my code not closing connections.
We do have stored procedures that run for a long time before they return results (around 15 seconds).
does anyone have any ideas on what could be causing this? I dont think raising the # of connections on the application server will fix this issue buecause if connections were running out then we'd see "Error on allocating connections"
Sample code snippet:
this.setSqlMapClientTemplate(getSqlTempl());
getSqlMapClientTemplate().queryForList("authentication.isUserDAO", parmMap);
this.setSqlMapClientTemplate(getSqlTemplDW());
List results = (List) parmMap.get("Result0");
I am using validate in my connection pool.

Based on the stack trace, the likely cause is that you are continuing to use a ResultSet after close() was called on the Connection that generated the ResultSet.

What is your DataSource framework? Apache Commons DBCP?
do you use poolPrepareStatement property in data source configuration?
Check the following:
Make sure testOnBorrow and testOnReturn are true and place a simple validationQuery like select 0 from dual.
Do you use au
do you use autoCommit? Are you using START TRANSACTION, COMMIT in your stored procedures? After several days of debugging we found out that you can't mix transaction management both in Java and in SQL - you have to decide on one place to do it. Where are you doing yours?
Edit your question with answers to this, an we'll continue from there.

When a db server reboots, or there are some problems with a network, all the connections in the connection pool are broken and this usuall requires a reboot of application server
And if broken connection detected, you shold create a new one to replace it in connection pool. It's common problem called deadly connections.