Of the two DB Connectors that are set up on the HCSC server, the DB Connector specified in the dbcon-xadisplayname property of the HCSC server setup definition file is used. If numerous requests are simultaneously sent from request reception via the business process, the HCSC server can not output all data to Database at one time because of performance bottleneck at DB connector. In such a case, a performance bottleneck occurs, causing performance degradation in the simultaneous execution of the business process. Therefore, you must set the multiplicity when collecting the execution logs of process instances. The following figure shows the occurrence of a bottleneck when a business process to be made persistent is used.

Figure 5-3 Occurrence of a bottleneck when a persistent business process is used

Of the two DB Connectors that are set up on the HCSC server, the DB Connector specified in the dbcon-xadisplayname property of the HCSC server setup definition file is used to extract messages from a queue in asynchronous (MDB (WS-R) or MDB (DB Queue)) standard reception. This DB Connector is also used to send messages for an asynchronous (MDB (WS-R) or MDB (DB queue)) service adapter. Therefore, you must examine the connection pool count in addition to the multiplicity when the execution log of process instances is acquired, when the HCSC server extracts messages from the queue for request reception, and when the service adapter sends messages to the transmit queue.

If numerous requests are simultaneously received by a queue, the resource adapter of Reliable Messaging cannot extract the messages simultaneously, causing a performance bottleneck. Furthermore, even when the multiplicity of the service adapter is increased, if the number of simultaneous executions is small when the service adapter sends messages to a queue, a performance bottleneck also occurs. The following figure shows the occurrence of a bottleneck when an asynchronous protocol is used.

Figure 5-4 Occurrence of a bottleneck when an asynchronous protocol is used

The multiplicity related to database access is set as shown in the following table.

Table 5-6 Properties for setting the multiplicity of a DB Connector

Definition file	Property	Description
Property file configured during setup of a DB Connector (LocalTransaction or XATransaction)	MinPoolSize	Minimum pool size
	MaxPoolSize	Maximum pool size

#1

Note that, when the maximum pool size has been increased, the number of simultaneous connections in the database must also be changed. (For HiRDB, this is pd_max_users, which is maximum number of connections of HiRDB.)

#2

For details about the maximum number of database connections used in the execution environment, see 3.1.2 Setting up the software required for the execution environment in the Service Platform Setup and Operation Guide.

Table 5-7 Properties for setting the multiplicity of Reliable Messaging

Definition file	Property	Description
Property file configured during setup of Reliable Messaging	MinPoolSize	Minimum pool size
	MaxPoolSize	Maximum pool size