Real Application Testing - Expert Oracle RAC Performance Diagnostics and Tuning - page 126

Figure 5-19. OEM—Replay client preparation
At this stage, the database is being prepared for replay. While this is being done, attempt to start clients from
remote Oracle servers or machines that have Oracle client installed.
[oracle]$ORACLE_HOME/bin/wrc MVALLATH/MVALLATH@obitst mode=replay replaydir=/OBITST_RMAN/EGCRAT/
Workload Replay Client: Release 11.2.0.2.0 - Production on Wed Mar 9 20:34:27 2011
Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved.
Wait for the replay to start (20:34:27)
Step 20
The next screen (not shown) displays the number of replay clients that are currently pointing to the test environment.
Once all the clients discovered have started to execute, select Next.
The next screen, Step 8 of the Replay Workload process is the final stage and gives the review the replay
definition. At this point, EM provides a warning to set the clock of the test/preproduction servers to the system
time of the capture environment, prior to the start of capture. This is critical if the database contains time-sensitive
information and to avoid SQL statements that execute based on time stamps from failing.
Click Submit, which starts the replay process. The next screen displays the replay progress.
Step 21
Once the replay process is complete, compare the results with the primary production environment. In a migration
project, when moving from single instance to RAC, the replay measurements on a single server should be equal to or
better compared to the current production environment.
In the comparison output shown in Figure 5-20 , there is a side-by-side comparison of the capture and replay
process indicating that they are almost identical in performance and response time. The lower “Database Time”
consumed by the entire workload indicates less consumption of resources; however, overall completion time has
been the same.