Compare DB2 Connect to non-DB2 Connect

In these tests, the Trade 6 workload driver sent all transaction requests directly to DB2® on z/OS®, bypassing DB2 Connect™. This set of results was compared to the scenario of DB2 Connect in a z/VM® guest using two virtual CPUs and 1 GB memory. The number of Trade 6 users were scaled from 500 to 700. The parameter, MAXAGENTS, was set high enough that the number of active connections was not limited. The z/VM LPAR was assigned five CPUs and for this test we assigned seven CPUs to the z/OS LPAR to support 700 Trade users.

See Figure 1 for details on the DB2 Connect in a z/VM guest using two virtual CPUs and 1 GB memory scenario results.

Figure 1 shows throughput using DB2 Connect and not using DB2 Connect and scaling users from 500 to 700.

Observations

Throughput increases for the bypass case, which is as expected. The impact of DB2 Connect is 6% to 8%, even with 700 users.

Conclusion

When the Trade 6 transactions are routed though DB2 Connect, throughput degrades up to 8%. This may be considered a very small impact to obtain predictable thread resource utilization on z/OS DB2.