Java: Chart Data Error - I/O Error: Connection Reset – OSKAR

This requires editing the ivizgroup.properties on your server in the configuration (conf) directory.

A database connection pool creates and manages a pool of connections to a database (db). Recycling and reusing already existing connections to a database is more efficient than opening a new connection. However there is one problem with connection pooling, a web application has to explicitly close the: result sets, statement's, and connection's. Failure of a web application to close these resources can result in them never being available again for reuse, those are called dead connections or a db connection pool leak. This can eventually result in your web application connections failing if there are no more available connections, because of these dead connections, you might see the following errors:

An error occurred while retrieving the data for the chart XXX: Invalid state, the Connection object is closed.

java.sql.SQLException: I/O Error: Connection reset Caused by: java.net.SocketException: Connection reset.

[DEBUG][2008-08-26 09:39:22,395][][DataSourceMgr] getDataSource(): active connections: 0, idle connections: 3

[ERROR][2008-08-26 09:39:22,395][][SystemMgr] checkRepositoryTables(): ERROR CODE: 0, SQL STATE: HY010, ERROR MESSAGE: HY010 java.sql.SQLException: Invalid state, the Connection object is closed.

System Configuration Error

The following error occurred while attempting to connect to the iDashboards repository database:

ERROR CODE: 0, SQL STATE: 08003, ERROR MESSAGE: 08003.

This document discusses in detail about the different reasons and recommendations for fixing the Chart Data Error – I/O Error: Connection Reset.

Reasons

Some of the reasons for the dead connections are the following:

If the database server goes offline and the application server is not restarted.
If the database server is in sleep mode.
The maxConnections property indicates the maximum number of connections that will be created by an iDashboards managed connection pool. If this property is missing or blank, a default value of 20 will be used. Connections will only be created and added to the pool on an as-needed basis, so the maximum number of connections may never be reached unless the iDashboards server is extremely busy. But for some reason the db.maxConnections is mistyped to set to 2 instead of 20 and the iDashboards server is kept extremely busy with many users attempting to use a new connection.

Recommendations

It is good practice to recycle the application server whenever you recycle the database server.
Make sure the database server is not in sleep mode.
Increase the db.maxConnections property to your needs if you have large number of users using the iDashboards application at a given point.
As a last resort you can always set db.validateConnections=true in your ivizgroup.properties, using notepad or text editor of your choice if the problem repeats. The validateConnections property indicates whether connections should be tested when they are returned to the connection pool after use. If true, a test query will be ran on each connection when it is returned to the connection pool. If it fails, the connection will be considered dead and removed from the connection pool. Since there is a small performance cost associated with testing connections, this property should be set to true only in cases where the repository database may go temporarily offline while the iDashboards application server remains online. Restart the Application Server after setting the property: db.validateConnections=true

This will validate a connection after it is used and expunge it from the pool if the validation fails. A user may see an error, but it will work on the next try. The iDashboards configuration (ivizgroup.properties) can be reviewed and revised to recover these abandoned database connections.

If the above is unable to resolve the issue, then please contact iDashboards Support for further assistance.