Several functions are added to the client driver APIs to control
the server, to clean up open handles and to delete unused
environments. These functions do not rely on open handles and are
put together into the BdbServerAdmin class.
You can shutdown the server using the
shutdownServer method:
BdbServerConnection conn =
BdbServerConnection.connect("localhost", 8080);
// Get an instance of the BdbServerAdmin class
BdbServerAdmin adminService = conn.adminService();
// Shutdown the server. After this method, close the connection.
adminService.shutdownServer();
// Close the connection.
conn.close();
You can test the server's reachability using the
ping method:
BdbServerConnection conn =
BdbServerConnection.connect("localhost", 8080);
// Get an instance of the BdbServerAdmin class
BdbServerAdmin adminService = conn.adminService();
// Test if the server is reachable. If the server is not
// reachable, an SDatabaseException is thrown.
adminService.ping();
...
You can get the version of Berkeley DB library used by the
server using the getServerBdbVersion
method:
BdbServerConnection conn =
BdbServerConnection.connect("localhost", 8080);
// Get an instance of the BdbServerAdmin class
BdbServerAdmin adminService = conn.adminService();
// Get the version of the Berkeley DB library used by the server.
String serverBdbVersion = adminService.getServerBdbVersion();
...
Sometimes a handle may be left open for a long time on the server. This can be caused by a client application error, crash or hang. If this handle holds critical resources (e.g locks), it may slow down or even block other client applications.
The Berkeley DB server can be configured to close these
inactive handles periodically with the
cleanup.interval and
handle.timeout properties. For more
information, see Server Configuration Options
In addition, the driver APIs also provide functions to clean up inactive environment and database handles. For example:
When an environment or database handle is closed, all handles that depend on it are also closed. For example, when an environment handle is closed, all transaction handles opened under the environment handles are also closed.
BdbServerConnection conn =
BdbServerConnection.connect("localhost", 8080);
// Get an instance of the BdbServerAdmin class
BdbServerAdmin adminService = conn.adminService();
// Close handles opened on the environment whose home directory
// is "env", if they have not been accessed in the last 10 seconds.
adminService.closeEnvironmentHandles("env", 10 * 1000L);
// Close handles opened on the database specified with the given
// environment home directory, database file name and sub-database
// name, if they have not been accessed in the last 10 seconds.
adminService.closeDatabaseHandles("home", "dbFile", "subDb", 10 * 1000L);
// Shutdown the server. After this method, close the connection.
adminService.shutdownServer();
// Close the connection.
conn.close();
With the embedded Berkeley DB, you can remove an environment and all its databases by removing the environment home directory and any additional data, log and blob directories. The driver APIs also provide a way to do this:
BdbServerConnection conn =
BdbServerConnection.connect("localhost", 8080);
// Get an instance of the BdbServerAdmin class
BdbServerAdmin adminService = conn.adminService();
// Delete the environment whose home directory is "env" and all the
// databases opened in it. Close all open handles on the environment
// and databases.
adminService.deleteEnvironmentAndDatabases("env", true);
// Shutdown the server. After this method, close the connection.
adminService.shutdownServer();
// Close the connection.
conn.close();