Java Dynamic Management Kit 5.0 Tutorial

Buffering Specifics

When the buffer is full and notifications need to be discarded, the time reference for applying the overflow mode is the order in which notifications have arrived in the buffer. Neither the time stamps nor the sequence numbers of the notifications are considered, because neither of these are necessarily absolute; even the sequence of notifications from the same broadcaster can be non-deterministic. And in any case, broadcasters are free to set both time stamps and sequence numbers as they see fit, or even to make them null.

The second parameter of the setCacheSize method is a boolean that determines whether or not the potential overflow of the cache is discarded when reducing the cache size. If the currently buffered notifications do not fit into the new cache size and this parameter is true, excess notifications are discarded according to the current overflow mode. The overflow count is also updated accordingly.

In the same situation with the parameter set to false, the cache will not be resized. You need to check the return value of the method when you set this parameter to false. If the cache cannot be resized because it would lead to discarded notifications, you need to empty the cache and try resizing the cache size again. To empty the cache, you can either pull the buffered notifications with the getNotifications method or discard them all by calling the connector client's clearCache method.

When the existing notifications fit within the new cache size or when increasing the cache size, the second parameter of setCacheSize has no effect.

Because several managers can connect through the same connector server object, it must handle the notifications for each separately. This implies that each connected manager has its own notification buffer and its own settings for controlling this cache. The overflow count is specific to each manager as well.