Oracle Database 11g: Database Replay, Part 2 - Page 3

May 30, 2008

Phase 3: Replaying the Workload

Since my target database has now been reset to its prior state just before workload capture was initiated and all my P+1 changes are now in place, at last I’m ready to initiate the replay of the workload. I’ll use EM Database Control to initiate the replay, as shown in Figure 2.4.1 below.

Once I’ve selected a directory that already contains a captured workload, Oracle 11g makes sure that I’ve reviewed all required prerequisites for a successful replay, including what external references (e.g. external files and directories) need to be resolved before proceeding, as shown in Figures 2.4.2 and 2.4.3 below.

Once all prerequisites have been confirmed, it’s time to set up the actual EM task that will perform the replay. Figure 2.4.4 shows how I set up the basics for this task ...

... and Figure 2.4.5 shows how I remapped the current connection strings generated during the initial workload capture so that the identical connection strings are used during this database replay operation.

As I described in the Database Replay primer article, Oracle 11g allows me to alter the frequency at which a workload is played back with extreme granularity. To keep this demonstration simple, I’ve accepted the default options shown in Figure 2.4.6.

It’s now almost time to start the Workload Replay Client (WRC) to play back the previously captured workload. As Figure 2.4.7 illustrates, my next step is to start the WRC with the appropriate parameters and then return to this screen and select the Next button to initiate the workload’s automatic replay:

I’ll start the replay session by opening a terminal session and invoking the WRC client executable. Note that I first changed my present working directory to /home/oracle/DBRControl before starting up the WRC:

$>  wrc system/oracle@orcl mode=replay replaydir=.
Workload Replay Client: Release 11.1.0.6.0 - Production on Thu May 22 19:28:59 2008
Copyright (c) 1982, 2007, Oracle.  All rights reserved.
Wait for the replay to start (19:28:59)
...

Returning to EM Database Control, I simply click on the Next button, and Oracle 11g acknowledges that it has taken control of any active database replay operations ...

... and that’s also reflected from within the terminal sessions themselves.

Wait for the replay to start (19:28:59)
...
Replay started (19:31:17)

Back at EM Database Control, the status of the database replay operation is constantly being monitored ...

..; until the replay operation is completed.

Wait for the replay to start (19:28:59)
...
Replay started (19:31:17)
Replay finished (19:37:02)