A Comprehensive Guide to IBM WebSphere Host Publisher Version 3.5

76 IBM WebSphere Host Publisher Version 3.5

The following fields are illustrated in (see Figure 4-5):

Pool Name

The name of the pool that owns connections. When requesting an available

connection, Integration Objects refer to a pool by this name. An Integration

Object that is an instance of a particular Java class can use connections out

of only one pool; multiple Integration Objects that are instances of different

Java classes can access connections from different pools.

Pool Definition Name

The name of the file containing the pool definition. This file is generated by

Host Publisher Studio along with associated Integration Objects. It also

references other definitions that are associated with this pool, such as the

connection definition and user list definition.

Active Connections

The number of connections allocated from the pool and currently connected

to the remote data source or application. Connections are allocated only as

needed. For example, if there are ten active connections, then at least ten

Integration Objects have concurrently requested an available connection.

In-Use Connections

The number of connections currently in use by an Integration Object.

Idle Connections

The number of connections currently available for the next Integration Object

request.

Unusable Connections

The number of connections returned to the pool by an Integration Object, but

left in an unusable state. These connections are eventually recycled and

re-established as available connections.

4.4.3 Pool definitions

A pool definition provides information about a collection of data source

connections. Some related definitions are associated with a pool definition, for

example, connection, user lists, connect and disconnect macro definitions, if

applicable.

Chapter 4. Administration 77

Figure 4-6 Pool Definitions window

In addition to creating associations between several other definitions, the pool

definition provides configuration parameters for all connections in the pool, such

as minimum and maximum pool size (in terms of number of active connections)

and connection timers.

The associated connection definition specifies how to access a data source or

application. For example, if the pool is for database connections, then the

connection definition contains the URL for accessing the database using the

Java Database Connection (JDBC) API. If the data source is a 3270 application,

then the connection defines TN3270E session parameters, such as the

TN3270E server's TCP/IP host name and port. Connections can also use

TN3270 servers.

Connect and disconnect macro definitions, applicable only for host pools, contain

the IBM Host On-Demand macros. Use these macros to navigate to the

application start screen and to disconnect the session and application,

respectively.

User lists list user IDs and passwords used to access the data source or

application. The connection definition and the associated user IDs and

passwords make up the pool of available connections.

Note: All defined connection pools appear in this window. In the Connection

Pools window, a connection pool is not listed until at least one connection is

allocated from the pool.

78 IBM WebSphere Host Publisher Version 3.5

The fields are (see Figure 4-6 on page 77):

Pool Definition Name

The name that Integration Objects use to request an available connection.

Type

Host indicates that this pool definition is for connections to 3270, 5250, and

VT applications. Database indicates that this pool definition is for connections

to databases.

Connection Definition Name

The name of the definition file that describes how to access the data source

or application.

Macro Definition Name

The name of the definition file that contains references to other files that

contain the Host On-Demand macros used to:

– Navigate a host application to the ready state for an Integration Object

– End a connection

– Recover a connection that has become unusable

This column applies only to host pools.

User List Name

The name of the user lists definition file referenced by the pool definition. It

contains the user IDs and passwords used to establish the connections in the

pool.

Click the triangle next to any pool to see these additional fields. For an example,

see Figure 4-7 on page 79.