On Thursday 21st April, there is a dual UKOUG Database and RAC, Cloud, Infrastructure and Availability special interest group.
For the first time, this even is being held in the fabulous Northern city of Manchester!
There are a dozen interesting, career-assisting, educational talks from end users, Oracle employees and a number of well known Oracle ACE’s at all levels, including Carl Dudley, Jonathan Lewis, Phil Brown and myself.
I will be talking about how (more...)
You have a session which is out of control. You decide to kill it. What options are available to you as a DBA?
Assuming you don’t have access to the O/S to be able to use O/S commands to kill the session (using kill -9 in Unix/Linux or orakill in windows to kill the thread within the process – “orakill sid thread”), you probably turn to:
alter system kill session 'sid, serial#, @inst_id' immediate;
By default on an Oracle RAC installation, the listeners are configured to allow any database to register with them. There is no security out of the box to determine which databases may register. While this makes it easy to create new databases without worrying about listener registration, this can cause potential problems in a real environment.
This can be dangerous working with RAC environments where the database registers with both a local and remote listener. The (more...)
This is a little note to myself on how to fix a corrupt spfile in clustered ASM. I hope you find it useful, too.
Let’s assume you made a change to the ASM (server) parameter file that causes an issue. You are most likely to notice this once CRS is restarted but parts of the stack fail to come up. If “crsctl check crs” mentions any component not started you can try to find out (more...)
If you’ve run an exachk report, y0u may have seen the following message with regard to your databases:
||Database parameter CLUSTER_INTERCONNECTS is NOT set to the recommended value
This check is commonly seen when a database is created on Exadata without using the custom “Exadata” templates included with the database creation assistant. These customized templates include a multitude of recommended parameter settings found in (more...)
I have recently configured Active/Passive Failover cluster using Grid Infrastructure 12cR1 and wrote document on that subject. Now I plan to use this environment and convert "test12" database from Single-Instance to RAC database.
There are several ways to convert non-RAC database to RAC database:
- using Database Configuration Assistant (DBCA)
- Oracle Enterprise Manager
- rconfig command line utility
In this post I will describe how to perform conversion using rconfig utility
I noticed something for the first time tonight when I was playing around in the Enkitec lab – something that I have been doing wrong for a while. When working in the lab, I often rely on the crsctl command to shut down the entire cluster stack for me. It’s really easy to use “crsctl stop cluster -all” followed by “dcli -l root -g ~/dbs_group /u01/app/18.104.22.168/grid/bin/crsctl stop crs” to get everything down (more...)
This post is about exploring the mechanisms used by Oracle Clusterware 22.214.171.124 to restrict remote service registration, i.e. the 12c new feature "Restricting Service Registration for Oracle RAC Deployments"Why is this useful?
This improvement of 12c clusterware and listeners over the 11.2 version is useful mainly for security purposes, for example as a measure against TNS poisoning attacks (see also CVE-2012-1675
), and it is particularly relevant for (more...)
Removing a service via srvctl has not historically resulted in the service being fully removed from the database and it would still be visible in DBA_SERVICES as show below in an 126.96.36.199 database:
Create the service:
$ srvctl add service -d orcl -s demo -r "ORCL1,ORCL2"
During my project work I had to tune the SOA dehydration store on more than one occasion. Through this posting I would like to share the tuning tips collected during these exercises. It is not a step-by-step guide, because with tuning there never is a 'one-size-fits-all' in my humble opinion, but I provide in general a guidance that you can use as a reference for your own situation. I will also refer to related Oracle (more...)
Original Post can be viewed at MGMTDB: Grid Infrastructure Management Repository
MGMTDB is new database instance which is used for storing Cluster Health Monitor (CHM) data. In 11g this was being stored in berkley database but starting Oracle database 12c it is configured as Oracle Database Instance. In 11g, .bdb files (more...)
Original Post can be viewed at Openfiler on Virtualbox and 12c Oracle Flex ASM
Last week Oracle released 12c database and Oracle blogosphere is bustling with lot of people posting details about new versions and setup. I too decided to take plunge and setup my own RAC cluster. I had (more...)
Original Post can be viewed at portmap: unrecognized service on RHEL6
Quick note for people using NFS for shared storage on RAC database. Till RHEL5 we had to ensure nfs,nfslock and portmap service has to be running. These services are required otherwise you will get following errors while mounting database (more...)
[I originally posted this over at the Pythian blog. If you're not following it, you should! Way more content, by far smarter people than lil ol' me.]
After reviewing my blog post about running EBS OVM templates in VirtualBox, two of my teammates suggested that I work on something with potentially broader appeal. Their basic message was, "This is really cool for us EBS nerds, but what about the Core DBAs?"
So how does "11gR2 RAC in an hour" sound? In this post, I'll demonstrate how to deploy the pre-built Oracle VM templates to create a two-node (more...)
This is just a post ot point out that ODA Patch 2.4 is out. ODA Patch 2.4 requires 2.2 or above to install.
A couple of Highlights of this release seem to be
- Enhanced odachk 2.16
- A trace file analyzer
- The ability to now use normal (more...)
Tuning has always being good fun and something like a challenge for me.
From time to time we are being asked to find out why something did run slow while you are sleeping; answering this question is, in most cases, a challenge.
My batch did run slow last night, can you let us know why? Or why did this query run slow? Are questions we, as DBAs, have to answer from time to (more...)
I have extended the Undo usage scripts to include two additional indicators:
1) undo change vector size statistics
2) Used undo records/blocks
and support for RAC infrastructure, so you can spot the hungriest UNDO eaters for any given instance.
Then the script for Oracle 11g is as follows:
set pagesize 400
set linesize 140
col name for a25
col program for a50
col username for a12
col osuser for a12
SELECT a.inst_id, a.sid, c.username, c.osuser, c.program, b.name,
a.value, d.used_urec, d.used_ublk
FROM gv$sesstat a, v$statname (more...)
update ( 10/10/2012 ): I have changed the script to make work better with hourly requests at it was causing issues. Thanks to Dominic Brooks for the trick
update ( 11/10/2012 ): Added ADDM and Global report generation
Since I got turbo boost (over 1000 hits a day-wooow) from Tanel Poder the Great, better I write something to deserve the fame. This one is a real quick one which made my life easier.
On my second week at current company, I had to cover Exadata for 2 weeks which were completely nightmare due to some problems. I had to (more...)
Earlier Oracle announced the Oracle Database Appliance which is a really cool RAC-in-a-box. And here at Enkitec office we are very lucky to get our hands dirty and play with this new beast On the photo below you will see the Oracle Database Appliance.
Andy Colvin has some detailed reviews about the Oracle Database Appliance.. check out these links if you want to see the internals of the machine
But this post will walk you through the installation and configuration of the Oracle Database Appliance.. well all I can say.. at the end of (more...)