Theuse of connection pooling improves application performance by doing the following:
■Creatingconnections in advance. The cost of establishing connections is moved outside of
thecode that is critical for performance.
■Reusingconnections. The number of times connections are created is signicantly lowered.
■Controllingthe amount of resources a single application can use at any moment.
JDBCresources can be created and edited using the Admin Console's Java tab ⇒Resources sub
tabfor the conguration. You can also use the wadm create-jdbc-resource and
set-jdbc-resource-propcommands. For more information, see the Sun Java System Web
Server7.0 Update 1 Administrator’sGuide.
Note– Each dened pool is instantiated during Web Server startup. However, the connections
areonly created the rst time the pool is accessed. You should jump-start a pool before putting
itunder heavy load.
JDBCresource statistics are available through the Admin Console, CLI, and stats.xml only.
Theyare not shown in perfdump. Some of the monitoring data is unavailable through the
AdminConsole and can only be viewed through the CLI using wadm get-config-stats and
throughthe stats.xml output.
Apool is created on demand, that is, it is created the rst time it is used. The monitoring
statisticsare not displayed until the rst time the pool is used.
JDBCResource Statistics Available Through the AdminConsole
Thefollowing table shows an example of the JDBC resource statistics displayed through the
AdminConsole:
TABLE2–9 JDBCResource Statistics
Connections 32
FreeConnections 0
LeasedConnections 32
AverageQueue Time 1480.00
QueuedConnections 40
ConnectionTimeout 100
Tochange the settings for a JDBC resource through the Admin Console, for the conguration,
choosethe Java tab ⇒Resources sub tab. Select the JDBC resource. The settings are available on
theEdit JDBC Resource page. To change the JDBC resource through the
command-line-interface,use wadm set-jdbc-resource-prop .
UsingMonitoringData to TuneYour Server
Chapter2 • Tuning Sun Java System Web Server 73