Pathway/iTS Web Client Programming Manual (H06.03+, J06.03+)

How to Compile, Build, and Maintain a Pathway/iTS
Web Client
HP NonStop Pathway/iTS Web Client Programming Manual—520270-003
2-15
11. Tune the Application for Performance by
Changing the Session-Length Parameter
•
Accept day/date/time operations
•
User conversion routines
These tasks are delegated to the Pathway/iTS web gateway requester threads under
the control of the TCP. Each task involves one complete socket communication cycle
(a write and a read) or one I/O operation in a session.
A session begins when the applet opens the communication channel with the host
NonStop by establishing a socket connection with the TCP. The session ends when
the connection is closed by the applet after the task delegated to the gateway thread is
completed.
While opening a session, the applet sends a connection request to the router process
on the NonStop. The router process assigns the connection request to a waiting
gateway thread associated with a TERM object. The gateway thread then establishes
a socket connection with the applet. The router distributes client connection requests
to the waiting gateway threads while balancing the load optimally among the TCP
processes in the Pathway environment.
The number of I/O operations in a session affects the performance of the application
environment. For example, if this number is specified as 5, then the session with the
client will be kept alive until 5 socket communication cycles are done. In other words,
one gateway thread, with which the connection was established at the beginning of the
session, will be dedicated to that client (applet) until it has performed 5 delegated
tasks. After the 5 tasks are completed, the socket connection is broken, the session is
closed, and the gateway thread is freed to service another connection request from an
applet.
There is one case where the specified number of I/O operations is ignored: the BT-ET
block. After a begin-transaction operation, the session is kept alive, regardless of the
specified number of I/O operations, until the end-transaction operation is done. After
the end-transaction operation, the session is closed.
The length of the session is important in view of the response times when several
hundreds of applets are running. One gateway thread should not be tied to one client
for a long duration. Neither should the length be too small, as each beginning of a
session incurs a fixed overhead of time and resources.
Pathway/iTS provides a default value for the number of I/O operations in a session.
You can modify this value to tune the application for optimal performance.
The value is specified in the sessionlength parameter in the file named
app-name _CONTROL.html generated during the conversion process. The contents
of this file are shown in Example. In this example, the INITPROG of the application is
named LOGON, and the name of the control file is LOGON_CONTROL.html.