BAS 6.6 JSS

Problem:

• Product Name: Borland Enterprise Server (AppServer)
• Product Version: 6.6
• Product Component: Java Session Service (JSS)
• Platform/OS Version: All

Frequently Asked Questions:

1. What tables need to exist in the ORACLE database to use it as a JSS backend datasource ?
2. Is stateful session bean failover provided by JSS absolutely reliable ?
3. Is stateful session bean failover based on OSAgent or Naming Service ?

Resolution:

What tables need to exist in the ORACLE database to use it as a JSS backend datasource ?

create table JSS_EJB (KEY VARCHAR2(100), VALUE LONG RAW, EXPIRATION NUMBER(20));

create table JSS_KEYS (STORAGE_NAME VARCHAR2(10), KEY_BASE NUMBER(20));

create table JSS_WEB (KEY VARCHAR2(100), VALUE LONG RAW, EXPIRATION NUMBER(20));

Warning: Please do not use Oracle"s BLOB type in the above tables, as we have seen problems with BLOB type in our internal tests. "LONG RAW" worked well.

Is stateful session bean failover provided by JSS absolutely reliable ?

The stateful session bean failover is not designed to be absolutely reliable in the BAS (nor the J2EE spec requires it). It can happen that the session to which a client has migrated to after a failover, does not have the most recent state of the original session failed. If this is not an option for you, consider persisting the critical state inside of an entity bean.

Is stateful session bean failover based on OSAgent or Naming Service ?

The stateful session bean failover is based on OSAgent technology. To make the failover working, it is required that each partition which is part of a cluster, uses the same OSAgent port.

The NS based failover requires that the object supporting failover is registered in the Naming Service. This is true for a Session Home, but not for the stateful session instance itself. Therefore, the NS failover will work only for the home object.