Tests show that FastDbClient has a 10% to 20% performance improvement over DbClient under extremely high load conditions.

The sub-option of the db_client option in the configuration file indicates if the client is a FastDbClient.Or user can create a FastDbClient by calling the app.createDbClient() method with the last parameter set to true.

The interface to get a FastDbClient is similar to the normal DbClient, as follows:

Usage

The use of FastDbClient is almost identical to that of the normal DbClient, except for the following limitations:

• Both the get and the use of it must be in the framework’s IO event loop thread or the main thread. If it is used in other threads, there will be unpredictable errors (because the lock-free condition is destroyed). Fortunately, most of the application programming is in the IO thread, such as within the processing functions of various controllers, within the filter function of filters. It is easy to know that the various callback functions of the FastDbClient interface are also in the current IO thread, and can be safely nestedly used.
• Synchronous transaction creation interfaces are likely to block (when all connections are busy), so FastDbClient’s synchronous transaction creation interface returns null pointers directly. If you want to use transactions on FastDbClient, please use the asynchronous transaction creation interface.

08.5