HP Integrity NonStop H-Series - Manual (Page 41)

Figure 2-2 Message Flow in a Spring Application
A Spring message flows through all the components in the following sequence:
1. Web client sends Spring application request to the NonStop TCP/IP subsystem through a
web browser.
2. The NonStop TCP/IP subsystem sends the request to the httpd process of the iTP WebServer.
If you are using the conventional TCP/IP, request is sent to the Distributor process of the
iTP WebServer. However, if you are using Parallel TCP/IP Library or NonStop TCP/IPv6,
the request is sent to the listener
httpd process.
3. The httpd processes of the iTP WebServer communicate with the NSJSP processes either
using Pathsend calls through TS/MP or directly with an NSJSP process using file system
calls. The first request is always routed to an NSJSP instance through TS/MP using Pathsend
calls. TS/MP determines the least loaded instance of NSJSP and routes the request to it.
Subsequent requests from the web client are either routed to a particular instance of NSJSP
through file system calls or are sent to an instance of NSJSP through TS/MP using Pathsend
calls.
For more information on Pathsend calls, see the HP NonStop TS/MP Pathsend and Server
Programming Manual.
4. The Spring application, which is deployed under NSJSP, processes the request and performs
the business validations.
5. Spring passes the request to the JDBC driver.
6. JDBC establishes the database connection with the NonStop SQL/MX database for retrieval
or manipulation of data. NonStop SQL/MX retrieves the data from the data repository.
7. The response or data received from the database is forwarded by Spring to NSJSP and iTP
WebServer to be displayed to the user.
Message Flow in a Spring Application on NonStop 41