HTTP Session Persistence Frequency (Sun Java System Application Server 9.1 Deployment Planning Guide)

Sun Java System Application Server 9.1 Deployment Planning Guide

HTTP Session Persistence Frequency

The number of requests per minute received by the HADB depends on the persistence frequency. Persistence Frequency determines how often Application Server saves HTTP session data to the HADB.

The persistence frequency options are:

web-method (default): the server stores session data with every HTTP response. This option guarantees that stored session information will be up to date, but leads to high traffic to HADB.
time-based: the session is stored at the specified time interval. This option reduces the traffic to HADB, but does not guarantee that the session information will be up to date.

The following table summarizes the advantages and disadvantages of persistence frequency options.

Table 2–1 Comparison of Persistence Frequency Options


Persistence Frequency Option	Advantages	Disadvantages
web-method	Guarantees that the most up-to-date session information is available.	Potentially increased response time and reduced throughput.
time-based	Better response time and potentially better throughput.	Less guarantee that the most updated session information is available after the failure of an application server instance.