Wednesday, May 09, 2007

Tackling the 10g dataguard GUI

After hearing all these great things about the dataguard management in 10g EMGC (our shorthand for Enterprise Manager Grid Control) and having been badly scarred from the 9i dataguard implementation, I just had to try this out.

For starters, I tried to create a database. Strangely, EMGC which can clone Oracle Homes, deep-drill into performance problems, manage tablespaces, backups, workloads, stats, coffee cups, user objects, and can slice-n-dice the universe, this EMGC... I could not find a button to create a database. Maybe I missed it. Which is easy to do in EMGC, because it has so many features (most of which work quite well), so many links and buttons and gizmos and ways to get to where you think you want to go. But I could not find "Create Database". So I opted to clone instead. I was not disappointed, either. The prompts and progression of screens was very intelligent, logical and reassuring. I have found that to be the case with a number of "advanced features" in EMGC; of course, there are times when you come to expect such great performance and useability and you run head-first into a brick wall of errors. But I'll get to that in a second...

Database, check. Navigate to the Data Guard section under "Management", and the feeling that you are being well cared for continues. Create Standby. Oops, no spfile. EMGC reports that you need to create an spfile. Strange that the GUI does not offer to do that for you. It is really simple; "create spfile from pfile;" and reboot the database. Ok, spfile, check. Create Standby.

What does that mean? No details, no message, no mention of a log file. This is my most frequent and biggest complaint with EMGC to date. They often forget to inform the user where they can look for more details. "Go to the log file" you would think. This is EMGC, which of the many logfiles do you want to look in? I do some looking around and spot emoms.log, which has a couple more characters, but still quite useless:
2007-05-08 15:08:15,273 [EMUI_15_08_15_/console/database/dataguard/create] ERROR em.dataguard validate.1125 -
CreateBean: ClassNotFoundException: null
2007-05-08 15:08:15,286 [149::EMUI_15_08_15_/console/database/dataguard/create] ERROR jobs.dbclone executeQuer
y.173 - TemplateUtil.executeQuery(): SQLException: Closed Connection SQL is
SELECT status FROM v$instance

So, gritting my teeth, I file an SR. I should have a separate blog entry on that. Filing SRs for OMS is not that fun. But... let us not digress anymore.

So after 20 hours, my SR is still unsolved. Fortunately, I did some simple experimentation and found that if I put the database in archivelog mode, the standby creation is just hunky dory. So again, why would the GUI not do that? Very simple to do. And why the ultra cryptic error?

Archivelog mode, check. Create Standby; finally, the GUI goes to the next screen and asks for some specifics. I want a standby on a remote host, using ASYNC LOG transport (MAXIMIZE Performance). I fill in passwords and click Submit. I am treated with a status of sorts ("View Job") and after 10 minutes or so (yes, a small database), I have a fresh, hot out of the oven standby database with a dataguard broker all set up. Cool beans!

The dataguard management screens are adequate. You can change the standby mode between Protection, Availability and Performance with a few clicks; these operations do a lot of work in the background, like create standby redo logs and reconfigure both sites. Very nice. There is an option to run a test application that generates a bit of redo (1.5 mb/sec in my case), which is another nice feature to do a really simple load test of your configuration. When in MAXIMIZE PERFORMANCE mode, I could not find a way to switch between ARCH transport and REDO; again, another easy operation that I would expect to see as part of the management screen.

Overall, I am pleased with this version of the dataguard GUI. I still have an itch over those errors, but at least the major objective was accomplished with no bloodshed. I plan to play around a little more with Failover and Switchover.

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