JDBCResource Statistics Not Available in the Admin Console
SomeJDBC statistics are available through the wadm get-config-stats command (using the
--nodeoption), through stats-xml, and through SNMP but not through the Admin Console.
maxConnections– The congured maximum size of the pool. Use as a reference for other
statistics.To change the maximum connections for a JDBC resource through the Admin
Console,on the Edit JDBC Resource page, edit the Maximum Connections eld. To change the
JDBCresource's maximum connections through the command-line-interface, use wadm
set-jdbc-resource-propand change the max-connections property.
peakConnections– The highest number of connections that have been leased concurrently
duringthe history of the pool. This number is a good indication on the upper limit on pool
usage.It is limited by the maximum connections setting.
countTotalLeasedConnections– The total number of times a connection has been handed out
bythe pool. Indicates total pool activity. Not tunable.
countTotalFailedValidationConnections– If connection validation is enabled, shows the
numberof times a connection has been detected as invalid by the pool. If this number is
relativelyhigh, it could signal database or network problems. Not tunable.
peakQueued– The highest number of connection requests that have been queued
simultaneouslyat any time during the lifetime of the pool. Not tunable.
millisecondsPeakWait– The maximum time in milliseconds that any connection request has
beenin the wait queue. A high number is an indication of high pool activity. The upper limit is
theJDBC resource setting wait timeout.
countConnectionIdleTimeouts– The number of free connections that have been closed by the
poolbecause they exceeded the congured JDBC idle timeout. To change the idle timeout for a
JDBCresource through the Admin Console, on the Edit JDBC Resource page, edit the Idle
Timeouteld. To change the JDBC resource's idle timeout through the
command-line-interface,use wadm set-jdbc-resource-prop and change the idle-timeout
property.
JDBCResource Connection Settings
Dependingon your application’s database activity, you might need to size JDBC resource
connectionpool settings. Attributes of a JDBC resource which aect performance are listed
below,along with performance considerations when setting values.
■Minimumconnections
Thesize the pool tends to keep during the life of the server instance. Also the initial size of
thepool. Defaults to 8. This number should be as close as possible to the expected average
sizeof the pool. Use a high number for a pool that is expected to be under heavy load, to
UsingMonitoringData to TuneYour Server
Chapter2 • Tuning Sun Java System Web Server 75