Wednesday, February 22, 2012

Oracle Exadata Management — Diary of an Exadata DBA

I recently had the chance to sit down with Deba Chatterjee, Senior Product Manager, Database Manageability to talk about Oracle Enterprise Manager 12c and how it's making Oracle Exadata management easier for DBAs. He had a great analogy that I wanted to share. "To describe how Enterprise Manager is making Exadata management simple and less complex, is by using an approach we call, 'Exadata Aware Database Performance Analysis'. The best way to illustrate how this works, is to use real-world scenarios," Deba added. Here is one of those scenarios—an excerpt from the diary of an Exadata DBA.

November 15th, Late Evening

Database performance has suddenly dropped becoming very poor. The same reports that were running fine a couple of hours ago are now taking forever to complete. The boss just left me a message that the CRM analytics director was pretty upset and wants to know why we have a performance problem.

I checked the queries and the execution plans both look the same with lots of smart scans and cell offloading. Suddenly, the response time has gone south and I cannot figure out why?

My first step was to look at the database performance page in Oracle Enterprise Manager 12c, which now comes with built-in Oracle Exadata support. Hey, what do I have here in the I/O tab? The Exadata system health button is red, that's not good. What's happening? I clicked the button and it took me to the Exadata health triage page, this is where I can see if I have potential issues such as;

  • Load imbalance
  • ASM related problems
  • Cell software or hardware failures
  • Cell configuration issues
  • Network related failures


The red Oracle Exadata system health button indicates potential issues impacting database performance.

Next, I noticed that the network status was red, it must be a network issue, right? I quickly checked the administration screen in the Infiniband Target Home page, and saw we had a degraded port in the Port Details status section. I disabled the bad port and allowed the network traffic to automatically fail over to its peer. I'll have to look into this later, for now I just wanted to get the system up and running.


View of the degraded port in Infiniband Switch Schematic.

I quickly re-checked the Exadata system health status again, it showed all green—looks like everything was working, problem solved. I called my boss back to give him the good news that the database performance was back up. I sure am glad all these things are integrated; otherwise I would have been here all night trying to figure this out.

Questions and Answers from the Oracle Enterprise Management Online Forum

By Scott McNeil

We received tons of questions from our recent Oracle Enterprise Manager 12c Online Forum, we wanted to continue to provide answers to the most popular ones. In this installment, we'll cover questions from the DBA and developer track.

Q. What kind of testing do you recommend for upgrading from Oracle Database 11gR1 to 11gR2?
A. Oracle Real Application Testing using Database Replay and SQL Performance Analyzer's capabilities are recommended for any Oracle Database upgrade. Check out these resources for more details: Oracle Real Application Testing datasheet and OTN for details on upgrading your database.

Q. Can I manage Oracle Exadata and traditional Oracle Databases from the same console?
A. Yes, you can manage Oracle Exadata and single instance and/or RAC databases from the same Oracle Enterprise Manager Cloud Control console, as well as WebLogic and many other targets. Check out this demo to see how.

Q. I thought Active Session History (ASH) was intended for real-time?
A. ASH can be use for both real-time and historical analysis. It is a black box that records session activities and helps to analyze across several performance dimensions. Click here to see a quick demo.

Q. What is the difference between Oracle Enterprise Manager 12c and Oracle Database Control?
A. Database Control is a subset which runs off a single database. Oracle Enterprise Manager 12c is a central repository which allows administrators to manage and monitor from a single console.

Q. How does Real-Time Automatic Database Diagnostics Monitor (ADDM) work – the database is hung right?
A. Real-Time ADDM, included in the Oracle Diagnostic Pack for Oracle Database, uses 2 different modes of connection to the database. A normal connection and a diagnostic mode that is a lock less, latch less connection which allows only few actions. Using the diagnostic mode connection Real-Time ADDM performs a hang analysis and determines any blockers in the systems. Check out this demo to see how Real-Time ADDM works.

Q. Can we achieve all the new functionality in Oracle Enterprise Manager 12c using terminal?
A. No. Features like ASH Analytics, Real-Time ADDM and Compare Period ADDM are only available using Oracle Enterprise Manager 12c's console.

Q. Is Real-Time ADDM available only in Oracle Enterprise Manager 12c?
A. Yes, Real-Time ADDM is a new feature in Oracle Enterprise Manager 12c.

Q. Can you explain the difference between Oracle Database 11g Monitor in Memory Access Mode vs. Real-Time ADDM direct access to SGA?
A. Real-Time ADDM does not use Memory attach mode. We use a proprietary connection method which connects using a lock less, latch less connection bypassing the SQL Access layer.

Q. Is there any limit on the number of days on which ASH can be used for analysis?
A. The in memory ASH data is typically available for 1 hour or till the point the memory buffer is flushed to disk. You can find out ASH retention by using: select min(sample_time), max(sample_time) from sys.WRH$_ACTIVE_SESSION_HISTORY;


Thursday, February 2, 2012

OTN detailed documentation on Lifecycle Management

Dear Friends,

Oracle have just released a detailed documentation on Database and Middleware Lifecycle Mgmt on OTN.

http://docs.oracle.com/cd/E24628_01/em.121/e27046.pdf

Standing at more than 700 pages, this is possibly one of the most detailed EM documentations released till date. It covers Provisioning, Patching, Change Mgmt, Compliance and Config Mgmt of different configurations in detail. The information map in section 1.2 takes you directly to sections of interest.

Oracle has also released a podcast on database-as-a-service today,

Wednesday, February 1, 2012

Cloud Management documentation enhanced and released

Friends,

The Cloud Management documentation has been enhanced and released for the public.

Oracle Enterprise Manager Cloud Administration Guide 12c Release 1 (12.1.0.1)

http://docs.oracle.com/cd/E24628_01/doc.121/e28814/toc.htm

Regards,

Porus.

Disclaimer

Opinions expressed in this blog are entirely the opinions of the writers of this blog, and do not reflect the position of Oracle corporation. No responsiblity will be taken for any resulting effects if any of the instructions or notes in the blog are followed. It is at the reader's own risk and liability.

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