WebSphere Commerce servers normally require enough
JDBC connections in the JDBC connection pool so that no WebSphere
Commerce threads need to wait for a connection. However, a WebSphere
Application Server iFeature allows WebSphere Commerce to run with
smaller JDBC connection pools. The iFeature defines and uses a reserve
pool of JDBC connections. Large WebSphere Commerce deployments
with more than 100 application servers might benefit from the reserve
pool because the reserve pool can reduce the database resource consumption
associated with large numbers of JDBC connections.
Before you begin
- Apply WebSphere Application Server feature FEF013660, which is
available from WebSphere Commerce customer support, or install WebSphere
Application Server fix pack 7.0.0.25 or later to your WebSphere Application
Server instance.
- Apply the interim fix for WebSphere Commerce APAR JR43306.
Procedure
- Enable preallocation of a JDBC connection for each WebSphere
Commerce Server thread that requires a database connection.
Add
the following configuration to the
<InstanceProperties>
element
of the WebSphere Commerce configuration file:
<com.ibm.commerce.server.TransactionManager preFetchJDBCConnection="true" />
For
more information about the WebSphere Commerce configuration file,
see
Updating the WebSphere Commerce configuration file.
- Define a WebSphere Application Server reserve pool.
Use the WebSphere Application Server administration console
to define a connection pool custom property. Use the name numberOfPoolReserves
for
the custom property and set the value of the property to 1.
- Determine the pool size that is appropriate for your environment.
Run performance tests with simulated workloads, measuring throughput
and response times. Start with the number of JDBC connections you
derive from
the instructions
for determining the data source connection pool size. From
that starting point, run further performance tests, gradually reducing
the connection pool size. Eventually you will see a performance degradation.
When that happens, increase the pool size (for example, by 10% or
20%) to allow for peak load fluctuations.