JDBC connection pool counters
PMI collects performance data for 4.0 and 5.0 JDBC data sources.
- For a 4.0 data source, the data source name is used.
- For a 5.0 data source, the JNDI name is used.
The JDBC connection pool counters are used to monitor the performance of JDBC data sources. We can find the data by using the Tivoli performance viewer and looking under each application server by clicking...
Application_server | JDBC connection poolWith the instrumentation level set to anything other than MAX, the values may be less accurate for TimeStatistics and CountStatistics (and in the case of CountStatistics, such as numConnectionHandles, can even be negative). This is due to counters not being synchronized. Synchronizing counters is very expensive in terms of resources, so it is only done when the instrumentation level is set to MAX.
Counter definitions
Name Key ID Description Granularity Type Level Overhead Num creates connectionPoolModule.numCreates 1 Total number of connections created Per connection pool CountStatistic All Low Num closes connectionPoolModule.numDestroys 2 Total number of connections closed. Per connection pool CountStatistic All Low Num allocates connectionPoolModule.numAllocates 3 Total number of connections allocated Per connection pool CountStatistic All Low Num returns connectionPoolModule.numReturns 4 Total number of connections returned Per connection pool CountStatistic All Low Pool size connectionPoolModule.poolSize 5 The size of the connection pool Per connection pool BoundedRangeStatistic All High Free pool size connectionPoolModule.freePoolSize 6 The number of free connections in the pool (apply to 5.0 DataSource only) Per connection pool BoundedRangeStatistic Basic High Concurrent waiters connectionPoolModule.concurrentWaiters 7 The number of threads that are currently waiting for a connection Per connection pool RangeStatistic All High Faults connectionPoolModule.faults 8 Total number of faults, such as timeouts, in the connection pool Per connection pool CountStatistic All Low Percent used connectionPoolModule.percentUsed 9 The average percent of the pool that is in use Per connection pool RangeStatistic Basic High Percent maxed connectionPoolModule.percentMaxed 10 The average percent of the time that all connections are in use Per connection pool RangeStatistic All High Avg use time (ms) connectionPoolModule.avgUseTime 12 The average time a connection is used (apply to 5.0 DataSource only). Difference between the time at which the connection is allocated and returned. This value includes the JDBC operation time. Per connection pool TimeStatistic All Medium Avg wait time (ms) connectionPoolModule.avgWaitTime 13 The average waiting time in milliseconds until a connection is granted Per connection pool TimeStatistic All Medium Num managed connections connectionPoolModule.numManagedConnections 14 The number of ManagedConnection objects in use for a particular connection pool (applies to V5.0 DataSource objects only) Per connection factory CountStatistic All Low Num connection handles connectionPoolModule.numConnectionHandles 15 The number of Connection objects in use for a particular connection pool (apply to 5.0 DataSource only) Per connection factory CountStatistic All Low Prepared stmt cache discards connectionPoolModule.prepStmtCacheDiscards 21 Total number of statements discarded by the least recently used (LRU) algorithm of the statement cache Per connection pool CountStatistic All Low JDBC time connectionPoolModule.jdbcOperationTimer 22 The amount of time in milliseconds spent running in the JDBC driver which includes time spent in the JDBC driver, network, and database (apply to 5.0 DataSource only) Per data source TimeStatistic All Medium