How does QZRCSRVS handle the java calling RPG?

Hi,

I'm looking the details of java program calling RPG program. My understanding is that the java program make use of "Remote command and distributed program call server". The QZRCSRVS handles the request. However, I really want to know the very basic mechanism of the how do QZRCSRVS handles to the request for calling RPG.

My concern is actually a performance issue based on 2 iSeries concepts:

1. user runs program by Job (login session)
2. RPGLE does not support multi-threading (although the option THREAD(*SERIALIZE) can make it thread safe, it is still not multi-threading.

The followings are my understanding. Please correct me if I am wrong.

Take an example, RPGLE program Pgm123 takes 2 seconds to complete.

For a simple java program calls Pgm123 should have not problem. 10 users
connect to iSeries and 10 sessions (job) should be created. Thus, there is
no problem as 10 Pgm123 run in 10 different jobs.

However, if the java program is running in Servlet and the web container
has 10 instances. 10 users call the Servlet and it calls the Pgm123. What
will happen? Does the last user have to wait for 20 seconds?

I believe that if I can understand the base mechanism of QZRCSRVS I can know the answer. If you know the details of QZRCSRVS, please let me know where I can find the details.

Thanks

Kevin