DB2 UDB for z/OS Version 8 Performance Topics - IBM Redbooks

SQLJ programs need to use explicitly defined connection contexts as always has been
recommended.
The test cases presented used WebSphere and the universal Type 4 Driver. The difference in
performance with using the Type 2 Driver and DB2 Connect instead is negligible as WAS will
perform connection pooling with the Type 4 Driver.
JCC Type 4 vs. JCC Type 4 with DB2 Connect - IRWW workload
Figure 7-13 illustrates the performance results of running IRWW workload using JCC Type 4
connection going from distributed platform to DB2 for z/OS in comparison of using JCC Type
4 to connect to DB2 for z/OS through DB2 Connect in gateway mode. The measurements
show a 2.3% [(382.14 – 373.73) / 382.14 * 100%] internal throughput degradation by going
through DB2 Connect rather than going directly to DB2 for z/OS.
In the DB2 Connect scenario, both JCC driver and DB2 Connect reside on the same
machine, and DB2CONNECT_IN_APP_PROCESS is defined as NO in order to have the
application connect to the DB2 Connect EE Server and then have the host connection run
within an agent.
400
350
300
250
200
150
100
50
JCC Type 4 Direct vs. JCC Type 4 with DB2 Connect
382.14 373.73
JCC Type 4 Direct JCC Type 4 with
DB2 Connect
Figure 7-13 JCC Type 4 vs. JCC Type 4 with DB2 Connect
Normalized z/OS
Transaction / Second
Conclusion
The new DB2 Universal Type 2 Driver performs as well and better than the legacy JDBC App
Driver and the Type 4 Driver performs better than the Type 3 Net Driver.
Recommendations
We recommend the usage of DB2 universal Type 2 Driver in a local DB2 environment. The
Type 4 Driver is preferred when accessing a remote DB2 server in a distributed environment.
Use the DB2 Universal Type 4 Driver to access a DB2 server directly when connections are
already pooled by other application servers, for example, WebSphere. FixPak 10 has been
recently made available and it supports connection concentration and sysplex workload
balancing.
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