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As part of the eXtend Composer 3270/5250 Connect, the
3270/5250 Server Console(s) gives the user the ability to not only manage the
3270 Pool connections, but also pre-initialize the pool.
In a production environment, the ability to pre-initialize the connection
pool provides a convenient method of enhancing the performance of the
application for the initial users. The
administration capabilities for the connection pool allow you to Reset, Refill,
and/or restore the discarded connections in the pool once the connection pool
has been established.
Although
this functionality provides flexibility and reduced overhead on initial user
requests, there is one drawback. The
user must access the 3270/5250 Server Console and perform these operations manually.
The servlets included with this article are designed to give the user the
capability of scheduling an automated service that will run at predefined times
(via a scheduled business object) as well as at server startup (via a server
event business object). The benefit
of this is that it provides a call to both the Reset Discarded and the
pre-initialize methods on a scheduled basis for the lifetime of the server.
In a mainframe environment, sometimes the systems are shut down or taken
offline after-hours for regular scheduled maintenance and are brought back up at
a scheduled time.
These
servlets will allow the Composer services to mimic this behavior by
re-initializing the connection pool at a predefined, scheduled time as well as
remove and/or reset any discarded connections in the pool at the time of
execution. The pre-initialize method can execute both before and after a
connection pool is established. Therefore if a certain number of users were
logged into the system previously, the connections will not be reset: only the
remaining number of available connections will be established.
The Reset Discarded method will execute only when a connection pool is
established. Otherwise the command will be ignored.
The
following table lists the Java files required to implement the servlets (http://ftp1.novell.com/pub/dev_articles/InitConnectionPool.zip
), along with a brief description of each. Any required user modifications to these
files are displayed in Italics. Once the necessary changes are made, the
files need to be compiled in the application server. (See your application
server documentation on how to perform this task.)
Also, on the SilverStream application server, the project jar file that
contains the deployed eXtend Composer Web Services as well as the connection
resources must be associated with the Scheduled Service Trigger object.
This is done in the SilverStream Business Object Designer.
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File
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Description
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TN3270.java
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Servlet
for the SilverStream Application server which contains two triggers:
scheduled and startup server event. You
will need to associate the deployed eXtend Composer project .jar file with
this servlet. The servlet is designed to respond to AgoScheduledEvent and
AgoServerStartEvent event types.
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PoolInit3270.java
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Source
class to access the 3270/5250 connection pool object.
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GenericTN3270Servlet.java
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Servlet
for the Websphere or Weblogic Application servers. See the appropriate user guide to install and configure
this servlet.
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TN3270.Java
And GenericTN3270Servlet.java requires two changes:
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Variable
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Change
to
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CONNECTION_NAME
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the
name of the connection that your 3270/5250 Logon component uses
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FULLY_QUALIFIED_CONNECTION_NAME
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a
concatenation of the following:
a)
the deployment context in the project jar
b)
a slash ("/") + the text "connection"
c)
the CONNECTION_NAME as described above. See source code for an
example.
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Introduction
