javax.resource.ResourceException: IJ000655: No managed connections available within configured blocking timeout (30000 [ms])

I read multiple files from modeshape and after reading a file I call the dispose method from the binary before reading the next one. So basically only one connection should be enough.  

I have turned on jdbc spy and this is the output:

Read file
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [DataSource] getConnection()
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [Connection] prepareStatement(SELECT payload FROM CONTENT_STORE WHERE cid = CAST(? AS VARCHAR) AND usage_flag = CAST(1 AS INTEGER))
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [PreparedStatement] setString(1, 6e63f04d75d046bdad6ed47b4ac792501a26f8ce)
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [PreparedStatement] executeQuery()
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [ResultSet] next()
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [PreparedStatement] close()
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [Connection] isClosed()
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [Connection] prepareStatement(SELECT payload FROM CONTENT_STORE WHERE cid = CAST(? AS VARCHAR) AND usage_flag = CAST(0 AS INTEGER))
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [PreparedStatement] setString(1, 6e63f04d75d046bdad6ed47b4ac792501a26f8ce)
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [PreparedStatement] executeQuery()
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [ResultSet] next()
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [PreparedStatement] close()
[jboss.jdbc.spy] java:/jdbc/modeshapeDS [Connection] isClosed()
Dispose binary
Read file
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