Monthly Archives: February 2014

Runtime Load Balancing Advisory in RAC 12c-addendum

A reader asked an interesting question yesterday with regards to the previous post on the subject: where did you get your service metrics from when you queried v$servicemetric-PDB or CDB$ROOT?

I queried the PDB, but this morning repeated the test to make sure the results are consistent, and they are. This is definitely something you’d hope for: you should not have different results in the same v$-view depending on the container you execute your query in for a given CON_ID.

During testing I noticed something interesting though. I queried gv$servicemetric but did not limit the result to the service I wanted to test with (FCFSRV). Here is the query against gv$servicemetric while the system was idle.

select inst_id,begin_time,end_time,service_name,cpupercall,callspersec,goodness,delta,con_id
from gv$servicemetric
where con_id = 3 and service_name  in ('FCFSRV','demopdb')
order by service_name, inst_id;

---------- ------------------- ------------------- -------------------- ---------- ----------- ---------- ---------- ----------
         1 19.02.2014 10:07:16 19.02.2014 10:07:21 FCFSRV                        0           0        100        100          3
         1 19.02.2014 10:05:57 19.02.2014 10:06:56 FCFSRV                        0           0        100        100          3
         2 19.02.2014 10:05:55 19.02.2014 10:06:54 FCFSRV                        0           0        100        100          3
         2 19.02.2014 10:07:19 19.02.2014 10:07:24 FCFSRV                        0           0        100        100          3
         1 19.02.2014 10:07:16 19.02.2014 10:07:21 demopdb                       0           0          0          1          3
         1 19.02.2014 10:05:57 19.02.2014 10:06:56 demopdb                       0           0          0          1          3
         2 19.02.2014 10:07:19 19.02.2014 10:07:24 demopdb                       0           0          0          1          3
         2 19.02.2014 10:05:55 19.02.2014 10:06:54 demopdb                       0           0          0          1          3

8 rows selected.

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Runtime Load Balancing Advisory in RAC 12c

This is a follow-up on yesterday’s post about services in the new 12c database architecture. After having worked out everything I needed to know about TAF and RAC 12c in CDBs I wanted to check how FCF works with PDBs today. While investigating I found out that the Runtime Load Balancing Advisory does not seem to work as expected in some cases. But I’m getting ahead of myself. First of all, here is my test case:

  • Oracle Linux 6.4 x86-64
  • Grid Infrastructure, i.e. January 2014 PSU applied
  • RDBMS, likewise patched with the January PSU
  • A CDB with just 1 PDB for this purpose, named DEMOPDB
  • Service FCFSRV is used

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RAC and Pluggable Databases

In preparation of the OUGN Spring Seminar and to finally fulfill at least a part of my promise from July I was getting ready to research RAC, PDBs and services for my demos. It turned out to become a lot more interesting than I first assumed.

RAC and Multi-Tenancy

So the first attempt to really look at how this works has started with my 2 node cluster where I created a RAC database: RAC12C, administrator managed with instance RAC12C1 and RAC12C2. The database is registered in Clusterware. Clusterware and RDBMS are patched to the January PSU, i.e.

The second step was to create a PDB for testing-it’s named DEMOPDB and available on both my instances by design. By the way-PDBs do not start automatically, it is your responsibility to start them when the database starts. I used a startup-trigger for this in the Consolidation Book, have a look at it to see the example. There are other ways available as I found out.

As soon as the PDBs is opened (in all Oracle deployment types, not limited to a RAC instance), a new service with the same name as the PDB is automatically started. As it turned out, using that service is the most reliable way to connect to the PDB:

SQL> connect user/password@single-client-access-name/pdbname

This works really well. Substitute your hostname with the SCAN for single instance. Now if you would like to implement some more interesting features (TAF/FAN+FCF/Application Continuity) you could create an additional service. The srvctl syntax has changed, Oracle now uses long parameter names (-service instead of -s), which doesn’t really respect the UNIX/GNU way of naming parameters (short parameter: single dash, long parameter name: double-dash) but that’s how it is.

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Public appearances first half of 2014

I had the great fortune to have had many of my abstract accepted for upcoming conferences and other public appearances, the first ones for this year are these:

OUG Ireland

The first conference I’ll be attending is in Dublin, for OUG Ireland 2014 on March 11.I’m going to help out with RAC Attack and also present about Technologies for Developing Highly Available Applications in RAC 12c at 14:50 for about 45 minutes. What can you expect? Here is the official abstract, I am looking forward to the presentation and the live demos.

Oracle offers a wealth of technologies to make your application more resilient to instance failure. This talk presents an overview of what is commonly considered in application development based on the Java programming language. You will learn about these technologies from a DBA’s point of view. Options will include TAF as a baseline followed by FCF and finally Application Continuity (incl. demos)

Exadata Workshop

At Enkitec we regularly organise Exadata workshops for those who are either interested in the technology or using it already but want to get more out of it. These workshops are scheduled quarterly, and I have already held two of these in London. The next one for Europe will take place on March 27 (Thursday), again in Oracle’s London City Office. If you are interested in the Exadata platform the workshop is an opportunity to discuss your deployment with other users or just to bounce ideas off other people then by all means come along (it’s free of charge)! The official link to this workshop is here:

I have updated the material to include the latest Oracle 12c cell software features as well as support for the new RDBMS architecture-Container Databases-and will update delegates on how this works and also how Exadata supports Oracle’s consolidation platform. There are many cool new features in 12c worth exploring and knowing about.

OUGN Spring Seminar

Next up is the Norwegian User Group’s Spring Meeting on April 3-4 where I have managed to secure two slots:

  • Oracle 12c features that didn’t make the marketing top 10
  • Advanced RAC programming features

The agenda is online and can be found here:

There are far too many great speakers to just link to my talks, feel free to browse (and register :)

For me the meeting starts on Wednesday 2nd when I’m flying to Oslo. This is without a shadow of a doubt a very good conference, and I can only recommend it-exactly like the others on this page. It is very well organised and definitely worth going. There are very few other conferences where you can mingle with the presenters and chat about all sorts of things in the same way as there. I have attended twice already and enjoyed it every time.


Enkitec E4

Enkitec’s Extreme Exadata Expo is one of the conferences with the highest technical content I can imagine. I attended last year and was really impressed by the speakers and the content. The impact on “Big Data” is clearly visible in the agenda and like last year you can find Exadata and “Big Data” talks.


Enkitec Extreme Exadata Expo

I am quite chuffed I made it on the agenda of the event! I’m going to present “Think Exa” together with my colleague Frits Hoogland.

In this presentation we are going to talk about setting your mindset on Exadata to overcome pre-ASM and pre-RAC habits. Unlearning some things we have been taught (or doing) for many years take its time, and we are hoping to give the audience an overview of what can be achieved with the platform.

At the same time that I am happy that I secured a speaker’s slot I am even more excited to attend the conference. Looking at the list of speakers who already confirmed their attendance it is going to be a blast. I am looking forward to seeing my colleagues from the United States but also to catch up with new and old friends.

Looking forward to seeing you at one of these events!