RMI and Web services

Question

Hi,
I have a question about the scalability of RMI with Oracle JVM.
What we intend to do is have about 10 SOAP webservices all interacting with our Oracle 8i instance. One of the developers suggestion is to use the Sun Java/SOAP Toolkit to make the WS stub code on UNIX and write java classes on the UNIX box to talk to more Java Classes in Oracle (using RMI), which in turn then pass data to Oracle PL/SQL packages which do the main bulk of the work (and the same of course happens in reverse). Our webservices will be called very often however (maybe about 1 call every 10 secs) at the moment possibly increasing to several calls per second in busy periods.
However i have heard that RMI really does not scale well at all (in fact another group of people I've talked to in our organisation advise us not to use it, and claim Oracle advise the same).
My suggestion was to handle it all in PL/SQL and use the utl_tcp package to handle the http traffic (with the possibility of migrating to Oracle 9i + utl_http). (along the same lines as http://otn.oracle.com/tech/webservices/htdocs/samples/dbwebservice/DBWebServices_PLSQL.html)
Any suggestions on this would be most appreciated.
Thanks.

Answer 1

In general I would concur with your thoughts on RMI. For some doc backup check out two pieces:
http://download-west.oracle.com/docs/cd/B10501_01/java.920/a96656/invokeap.htm#1011867
and then also the de-support of J2EE characteristics in general:
http://download-west.oracle.com/docs/cd/B10501_01/java.920/a96656/intro.htm#1006743
The basic focus of the Java engine is on J2SE applications.
To answer the SOAP approach, the development effort is primarily focussing on using the SOAP Java stack and loading it into the database as per this paper and example:
Paper: http://otn.oracle.com/tech/webservices/htdocs/dbwebservices/Database_Web_Services.pdf
Example:
http://otn.oracle.com/sample_code/tech/java/jsp/samples/wsclient/Abstract.html
This gives the same result as the PL/SQL example you point to but on a service by service approach a fairly simplified development approach. This should work in 8i as well (use these instructions to set up the stack: http://otn.oracle.com/sample_code/tech/java/jsp/loadjars.htl)
That said, the PL/SQL approach should also work (though like you say it needs to be tailored to 8i's PL/SQL capabilities) but you don't get much help from the product beyond UTL_HTTP whereas the Java approach gives a pre-built infrastructure that can also be upgraded as we move to JAX-RPC, the emerging standardized Java approach to implementing Web services.
Mike.