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Pool Manager

The Pool Manager activity provides information about the internal state of the connection pool, as well as some usage statistics. It is also possible to terminate existing pooled connections by providing the name of the pool and the ID of the connection to terminate.

If the Pool Manager runs before any pooled connections are instantiated, a document containing only the topmost node is returned.

The ActiveMatrix BusinessWorks Plug-in for CICS's connection pool is slightly different from most pooling mechanisms. The remote end of the connection, in this case, the CICS socket listener program, is managed by the CICS administrator and terminates idle connections once they exceed thresholds established by the CICS administrator. This means that the ActiveMatrix BusinessWorks activity could obtain a pooled connection that has been closed since it was last used. In this case, the connection is simply re-established incurring a small overhead.

From the performance tuning point of view, this connection pool provides throughput improvements only so long as connections do not remain idle for long periods. The time period in question is the shorter of the maximum connection lifetime established by the CICS administrator, or the pool's max lifetime parameter.

When sizing the connection pool, ask the CICS administrator how many connections he permits the socket listener to instantiate at any given time. Then divide that number by the number of machines your application is deployed on since each deployment uses its instance of the pool. Exceeding the limits established by the CICS administrator results in activities getting errors when acquiring a connection.

Configuration Tab

Table 11 lists and describes the fields under the Configuration tab.

Table 11 Fields Under Configuration Tab: Pool Manager Activity

Field	Global Variable	Description
Name	N	A name for this activity. Default: CICS Connection Pool Manager
Description	N	Description of the activity.

Input Tab

Table 12 lists and describes the fields for Input (root node).

Table 12 Fields Under Input Tab: Pool Manager Activity

Field	Global Variable	Description
ConnectionPool		A node representing a region's connections. If there is any question about what to use for input, simply run the activity with no input and refer to the activities output for reference.
regionresource	N	The URL name of the region resource. The named region node is the subject of the KillConnection and SetActiveHost commands. It does not limit the report to connections in this node. Each invocation of the ConnectionPool activity reports the status of all connections in all pools. Example: /Regions/AbcPooled.cicspi
KillConnection	N	A string representation of the connection number to terminate, or an '*' to terminate all connections in the pool.
SetActiveHost	N	Specify a host and port for the Poolmanager to use. For region resources defined to represent a group of CICS regions that are all similarly configured, you can explicitly tell the Poolmanager to change to another host:port. This provides a highly available application deployment. Enter the region name in the regionresource field and the URL of the CICS region to connect to in the SetActiveHost field and run the pool manager interaction.

Output Tab

Table 13 lists and describes the fields for the Output tab. It provides an xml document describing the current state of all connection pools for the ActiveMatrix BusinessWorks instance on which the activity runs. The root node is "PoolmanagerOut" and has a single repeating child.ConnectionPool:

Table 13 Fields Under Output Tab: Pool Manager Activity

Field	Description
ConnectionPool
regionresource	The URL name of the region resource. Example: /Regions/AbcPooled.cicspi
ActiveHost	If the region represents a set of hosts for redundancy purposes, the currently active host URL is displayed. If there is only one host on the Region Resource, this field is empty.
PoolSize	The number of connections this pool is configured to create.
PoolmanagerRequests	The number of requests for a connection made to this pool since its instantiation.
PoolmanagerWait	The number of requests that were required to wait because all connections in the pool were occupied.
PoolmanagerTimeout	The number of requests that were timed out while waiting for a connection.
Connection	Statistics for each connection
ConnectionID	The numerical number of the connection. This is the number to enter in the input tab's KillConnection field to have this connection terminated.
ConnectionRequested	The number of times this connection has been used.
ConnectionClosed	The number of times this connection was requested only to find that the associated CICS sockets listener had hung up due to its timeout. In these cases the connection is simply reestablished.

Error Output Tab

If an error is encountered, for example if no pooled sessions exist, an exception of type CicsPiException is generated.

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