One of the more interesting features in Oracle 12c RAC is application continuity. Why do I believe it is? Because it relieves developers from having to think about retrying connections and catch SQLExceptions in the code. I already thought that Fast Application Notification and Fast Connect Failover (FCF) are great, (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 22.214.171.124 database:
Create the service:
$ srvctl add service -d orcl -s demo -r "ORCL1,ORCL2"
Since the first patch for Oracle 12c has been made available I was of course keen to see how to apply it. For a first test I opted to use my 3 node RAC cluster which is running on Oracle Linux 6.4 with UEK2. This post is not terribly (more...)
Running RAC? (Why? No, really, WHY? Never heard of DataGuard? With a broker?)
Not sure if you’ve configured it correctly?
Not sure if you have all of the recommended initialisation parameters set?
All recommended RPM’s installed?
All daemons running?
etc, etc, etc,
Well, as of Oracle 11. (more...)
Today, I needed to update the IP adresses of scan name in Oracle 11gR2 RAC environment. As you know, these IP addresses are defined in DNS but they also stored in Oracle Clusterware resource configuration to tell which IP addresses will be served by SCAN VIP services. So when you (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 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’ve worked on 24×7 systems for more than a decade, and I have a real dislike of downtime. For one, it can be a real pain to agree any downtime with the business, and while RAC can and does help when you do work in a rolling fashion, there is still risk.
The promise of online patching has been a long one, and it is only recently that I dipped my toe in the water with them. Unfortunately, they are not a panacea, and in this blog posting I’m going to share some of the downsides.
Of course not all (more...)
Or what happens when you don’t have node affinity.
Here’s an old, short post that was lying around unpublished.
SQL executed on the 14th on node 2, on 15th on node 1.
|DT||SQL ID||Node||Rows||Execs||Elapsed||Cluster Wait Time|
Timings in seconds.
32625 seconds is just over 9 hours, of which 32175 is cluster wait time.
Database services and application datasource config have now been reconfigured to the extent that there is node affinity and the data required for the workload on node 1 is completely segregated (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...)
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...)
Recently I was given three virtual machines running Oracle Enterprise Linux 5 and Oracle 11gR2 RAC on Oracle VM 2.2.1, copied straight from /OVS/running_pool/. I had to get these machines up and running at my lab environment, but I found hard to setup the network. I’ve spent half day in debugging without success, but finally found a workaround, which I’ll explain here.
Just a little technical notes – Oracle VM (xen) has three main setup configurations within /etc/xen/xend-config.sxp:
Bridge Networking – this configuration is configured by default and it’s simplest to configure. Using this type of networking (more...)
A couple of things 2.3 is not a cumulative patch if you are running 2.1 you will need to apply the 2.2.0 patch before proceeding to 2.3.0 .
if you (more...)
11gR2 comes with several important changes and improvements to the clusterware in general and in particular the way listeners are managed. While the listener process is still the 'good old' process tnslsnr (Linux and Unix), it is now started from the grid home (as opposed to database oracle home). Moreover listeners are divided in two classes: node listeners and scan listeners, although they use the same binary for (more...)
When instance fails in Oracle RAC, the services that were using this instance as a preferred instance are automatically relocated to instances marked as available for this service. But after the failed instance recovers and starts up again, the relocated services are not moved back and need manual srvctl relocate service command from administrator to move them back.
Here is a little Bash script to automate this process. Oracle Clusterware (Grid Infrastructure) can execute user callout scripts on FAN events, like INSTANCE up/down. Place this script under $GRID_HOME/racg/usrco/ and set the execute bits on the file. Then clusterware will execute (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 time.
Oracle has provided us with many tools to dig out information about past operations. We have EM, AWR, ASH, dba_hist_* tables, scripts (more...)