Corporation Server User Manual

Programming Guidelines 4-1

Programming Guidelines

This chapter describes programming guidelines for SIP Servlet applications in the

following sections:

■ Introduction

■ Marking Applications as Distributable

■ Storing Data in Application Sessions

■ Avoiding Static Data

■ Avoiding Blocking Calls

■ Invalidating the SipApplicationSession and SIPSession

■ Monitoring the Memory Usage

■ Avoiding Storing Shared Resources in Sessions

■ Avoiding Creating Threads

■ Creating B2BUA Applications

Introduction

For an application to take full advantage of OCMS as a JSR 116 SIP Servlet Application

platform, observe the following recommendations.

Marking Applications as Distributable

For stateful applications, that is applications that save state in SipSessions or

SipApplicationSessions, to be highly available in a SIP Application Server cluster, the

sip.xml as well as the web.xml file must contain the <distributable> element. Marking

applications as distributable will make sure that the application and session state is

replicated to cluster nodes that will be able to resume execution of the session in the

event of a failure of a cluster node.

There are performance implications related to how session state is replicated in a

distributable environment. Replication is triggered each time there is a setAttribute()

call on the session object, so large numbers of such calls in a servlet may impact

performance.

For OC4J there are additional requirements if the application is packaged as an

Enterprise Archive. See the Oracle Communication and Mobility Server Administration

Guide for details.