TRANSFER Installation and Management Guide

Idle Sessions
Managing a TRANSFER System
11–6 068837, Update 1 to 013198 Tandem Computers Incorporated
When initializing the model depot and model group depot, be aware of the initial
profile values for item retention time that Tandem provides and the options to change
the values:
The default value provided by Tandem for the depot and the group-depot profile
item retention time attribute is infinity. Lower this value when initializing the
model depot to set a constraint for correspondent and group depots.
The default value provided by Tandem for item retention time for the special
folder INBOX is infinity. If, however, you set the depot item retention time, that
constraint applies to the INBOX. In addition, you can initialize the model depot
with a lower item retention time for INBOX. The retention time for INBOX applies
both to items saved and packages delivered to the folder.
The default retention time provided by Tandem for special folder OUTLOG is 24
hours. You can change this value to any value less than the depot constraint.
Retention time for special folder WASTEBASKET cannot be changed; items are
deleted at the end of every correspondent session.
Note that depots created before TRANSFER version B10 do not have the retention time
profile element and have the equivalent to an infinite item retention time.
For more information about initializing the model depot and the model group depot,
see Volume 1 of the TRANSFER Administration Guide, the Reference Manual.
Idle Sessions You can manage the length of time that sessions remain idle before TRANSFER ends
the sessions by logging them off.
The CHECKSESSIONHOUR PARAM on the A-TSCHED server class tells TSCHED
when to check for expired sessions. At that time, TSCHED marks every record in the
Session file with the current timestamp. This is known as the session expiration time;
the default time is midnight. If you want to change the CHECKSESSIONHOUR,
choose an hour when TRANSFER activity is low.
Each time a correspondent issues a UOW that requires a session (most UOWs do),
TISERV reads the correspondent’s record in the Session file. If the session expiration
time contains a timestamp, TISERV changes it to binary zeroes to indicate the session
has been used.
When the next CHECKSESSIONHOUR arrives 24 hours later, TSCHED again reads all
the session records. If a record has a timestamp in its session expiration time, that
session has not been used during the past 24 hours. If the difference between the
session expiration and the current time is equal to or greater than the number of hours
in the TWORK IDLESESSIONDELAY PARAM, TSCHED ends the session.
A session cannot expire until it passes through CHECKSESSIONHOUR twice: once to
set the session expiration time, and a second time to detect that the session has not
been used since the last CHECKSESSIONHOUR. Since CHECKSESSIONHOUR
occurs only once in a 24-hour period, the minimum useful value for
IDLESESSIONDELAY is 24 hours.