Web Container Settings
Manager Properties: Reap Interval
Modifying the reap interval can improve performance, but setting it without considering the nature of your sessions and business logic can cause data inconsistency, especially for
For example, if you set the reap interval to 60 seconds, the value of session data will be recorded every 60 seconds. But if a client accesses a servlet to update a value at 20 second increments, then inconsistencies will result.
For example, consider an online auction scenario as follows:
■Bidding starts at $5, in 60 seconds the value recorded will be $8 (three 20 second intervals).
■During the next 40 seconds, the client starts incrementing the price. The value the client sees is $10.
■During the client’s 20 second rest, the Application Server stops and starts in 10 seconds. As a result, the latest value recorded at the 60 second interval ($8) is be loaded into the session.
■The client clicks again expecting to see $11; but instead sees is $9, which is incorrect.
■So, to avoid data inconsistencies, take into the account the expected behavior of the application when adjusting the reap interval.
Disable Dynamic JSP Reloading
On a production system, improve web container performance by disabling dynamic JSP reloading. To do so, edit the
<servlet>
52 | Sun GlassFish Enterprise Server 2.1 Performance Tuning Guide • January 2009 |
