Techniques for monitoring IBM Data Server Driver for JDBC and SQLJ Sysplex support

To monitor IBM® Data Server Driver for JDBC and SQLJ Sysplex support, you need to monitor the global transport objects pool.

You can monitor the global transport objects pool in either of the following ways:
  • Using traces that you start by setting IBM Data Server Driver for JDBC and SQLJ configuration properties
  • Using an application programming interface

Configuration properties for monitoring the global transport objects pool

The db2.jcc.dumpPool, db2.jcc.dumpPoolStatisticsOnSchedule, and db2.jcc.dumpPoolStatisticsOnScheduleFile configuration properties control tracing of the global transport objects pool.

Start of changeExample: The following set of configuration property settings cause error messages, dump pool error messages, and transport pool statistics to be written every 60 seconds to a file named /home/WAS/logs/srv1/poolstats: End of change

Start of change
db2.jcc.dumpPool=DUMP_SYSPLEX_MSG|DUMP_POOL_ERROR
db2.jcc.dumpPoolStatisticsOnSchedule=60
db2.jcc.dumpPoolStatisticsOnScheduleFile=/home/WAS/logs/srv1/poolstats
End of change

An entry in the pool statistics file looks like this:

Start of change
time Scheduled PoolStatistics npr:2575 nsr:2575 lwroc:439 hwroc:1764 coc:372 
aooc:362 rmoc:362 nbr:2872 tbt:857520 tpo:10
group: DSNDB port: 446 hwmpo: 20 twte: 5 ngipr: 50 ttcpto: 2
   member: port: 446 DB1A hwmiut: 6 hwmt: 2 tmct: 1 trto: 0
   member: port: 446 DB1B hwmiut: 7 hwmt: 2 tmct: 1 trto: 0
   member: port: 446 DB1C hwmiut: 6 hwmt: 1 tmct: 0 trto: 1
End of change The meanings of the fields are:
npr
The total number of requests that the IBM Data Server Driver for JDBC and SQLJ has made to the pool since the pool was created.
nsr
The number of successful requests that the IBM Data Server Driver for JDBC and SQLJ has made to the pool since the pool was created. A successful request means that the pool returned an object.
lwroc
The number of objects that were reused but were not in the pool. This can happen if a Connection object releases a transport object at a transaction boundary. If the Connection object needs a transport object later, and the original transport object has not been used by any other Connection object, the Connection object can use that transport object.
hwroc
The number of objects that were reused from the pool.
coc
The number of objects that the IBM Data Server Driver for JDBC and SQLJ created since the pool was created.
aooc
The number of objects that exceeded the idle time that was specified by db2.jcc.maxTransportObjectIdleTime and were deleted from the pool.
rmoc
The number of objects that have been deleted from the pool since the pool was created.
nbr
The number of requests that the IBM Data Server Driver for JDBC and SQLJ made to the pool that the pool blocked because the pool reached its maximum capacity. A blocked request might be successful if an object is returned to the pool before the db2.jcc.maxTransportObjectWaitTime is exceeded and an exception is thrown.
tbt
The total time in milliseconds for requests that were blocked by the pool. This time can be much larger than the elapsed execution time of the application if the application uses multiple threads.
sbt
The shortest time in milliseconds that a thread waited to get a transport object from the pool. If the time is under one millisecond, the value in this field is zero.
lbt
The longest time in milliseconds that a thread waited to get a transport object from the pool.
abt
The average amount of time in milliseconds that threads waited to get a transport object from the pool. This value is tbt/nbr.
tpo
The number of objects that are currently in the pool.
Start of changegroupEnd of change
Start of changeThe data sharing group for which transport pool statistics were gathered.End of change
Start of changeportEnd of change
Start of changeThe port number of the data sharing group or member.End of change
Start of changehwmpoEnd of change
Start of changeThe maximum number of pool objects that were created since the pool was created.End of change
Start of changetwteEnd of change
Start of changeThe number of times that the maxTransportWaitTime value was exceeded since the pool was created.End of change
Start of changengiprEnd of change
Start of changeThe number of times that the group IP address was used since the pool was created.End of change
Start of changettcptoEnd of change
Start of changeThe total number of times that members of the data sharing group had a connection timeout when they were establishing a new connection.End of change
Start of changememberEnd of change
Start of changeThe member of the data sharing group for which transport statistics were gathered.End of change
Start of changehwmiutEnd of change
Start of changeThe maximum number of in-use transports for the data sharing member since the pool was created.End of change
Start of changehwmtEnd of change
Start of changeThe maximum number of transports that have been allocated to the data sharing member since the pool was created.End of change
Start of changetmctEnd of change
Start of changeThe number of times that the memberConnectTimeout value was reached for the data sharing member since the pool was created.End of change
Start of changetrtoEnd of change
Start of changeThe number of times that a read timeout occurred for the data sharing member since the pool was created.End of change

Application programming interfaces for monitoring the global transport objects pool

You can write applications to gather statistics on the global transport objects pool. Those applications create objects in the DB2PoolMonitor class and invoke methods to retrieve information about the pool.

For example, the following code creates an object for monitoring the global transport objects pool: 
import com.ibm.db2.jcc.DB2PoolMonitor;
DB2PoolMonitor transportObjectPoolMonitor =  
        DB2PoolMonitor.getPoolMonitor (DB2PoolMonitor.TRANSPORT_OBJECT);

After you create the DB2PoolMonitor object, you can use methods in the DB2PoolMonitor class to monitor the pool.