Pythian Group

For this blog I have compiled the main information specifically considering 11gR2 platform, but the concepts and idea also apply for older platforms as well.

Oracle provides the following JDBC drivers:

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It started out innocently enough: Two node RAC cluster on two Linux RHEL5 with Netapp NFS used as shared filesystem for all shared files. My favorite OS and storage, so I felt confident that clusterware installation will be as smooth as it usually is. I told the customer that this can be done in 3 hours.

What I didn’t take into account is that this was my first 11gR2 installation, and that much have changed since 11gR1. As things turned out, it took over 20 hours of my time and a lot of help from colleagues and even former colleagues before we had a successful installation.

The time it takes you to read this blog post (and any other on this subject) is likely to be time well spent.

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Welcome to Log Buffer, the weekly news update of happenings in the database world.

A big shout out to Pythian team members Andrey, Gwen, Fahd, and Don for their submissions. We have lots of news and recommended reading this week so let’s get going with Log Buffer #209.

Andrey Goryunov’s top picks:
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The past four days have found me very frustrated and at wits’ end while testing upgrades of standalone Oracle Grid Infrastructure (ASM) 11.2.0.1 to 11.2.0.2 on RHEL/OEL 5 VMs. The upgrade would seem to go fine, but after rebooting, I would see ASM and LISTENER running under the old (11.2.0.1) grid home directories again.

Looking at /etc/oratab, I saw this:

$ grep -i asm /etc/oratab
+ASM:/u01/app/grid/product/11.2.0/grid_1:N              # line added by Agent

grid_1 is the old grid home, I expect to see grid_2. The comment about being added by Agent led me to a path where I eventually took a look at /etc/init.d/ohasd, which is basically the master script that starts everything up. I noticed that this file hadn’t been updated as part of the patching, and contained this:

$ grep -i crs_home /etc/init.d/ohasd
ORA_CRS_HOME=/u01/app/grid/product/11.2.0/grid_1
export ORA_CRS_HOME

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Just recently I came across another unclear error message while troubleshooting an Oracle Instance registration with SCAN Listener. This post is one of the posts which may save quite a bit of time for people who will hit the same issue.

The errors message I got configuring a database just moved to run under 11GR2 Oracle Cluster control is as following:

SQL> alter system set remote_listener='scan.usolygrid-prod.cinram.com:1521';
alter system set remote_listener='scan.your.domain.com:1521'
*
ERROR at line 1:
ORA-02097: parameter cannot be modified because specified value is invalid
ORA-00119: invalid specification for system parameter REMOTE_LISTENER
ORA-00132: syntax error or unresolved network name
'scan.your.domain.com:1521'

SQL>

I was quite sure that the syntax I used was 100% correct as other instances running on the same host used the same remote_listener parameter value.
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Hello Everyone,

This is one of my fist posts under Pythian’s blog. I will try to keep those short and simple at the beginning.

Recently I was troubleshooting a new GNS (Grid Name Services) functionality.

For more information please see here: Oracle Clusterware Network Configuration Concepts.

I have noticed that there is a-trace-level parameter in the GNS process string.
# ps -ef | grep gns
root 26790 1 2 14:41 ? 00:00:00 /u01/app/11.2.0/grid/bin/gnsd.bin -trace-level 0 -ip-address 10.10.193.201 -startup-endpoint ipc://GNS_hostrac01_23867_408c49e351f1f6a8
root 26825 17210 0 14:41 pts/1 00:00:00 grep gns


Unfortunately there is no description as of now in the documentation or MOS on how to change it to generate invaluable diagnostic information.
NOTE: I am sure the documentation will be updated in Database 12c version (c for Cloud ;)

For a time being the following should work for you:

# /u01/app/11.2.0/grid/bin/crsctl modify resource ora.gns -attr "TRACE_LEVEL=6"
# /u01/app/11.2.0/grid/bin/srvctl stop gns
# /u01/app/11.2.0/grid/bin/srvctl start gns


I hope that this advice will help you to diagnose your GNS issue.

I will blog about the way I resolved future GNS-related issues later on.

It looks like I have said too much for my very first post already.

See you around,

Yury

Just another DBA from down under

After covering hardware components of Sun Oracle Database Machine in part 1, our grand tour continues with a look at the software side. With the prominent exceptions of the Exadata storage server software and the Oracle database itself, the software stack is based on well-known and widely used open source products.

Database Nodes

The database nodes all run Oracle Enterprise Linux 5.3, a virtual clone of Red Hat Enterprise Linux 5.3, but also including some small performance-related kernel tweaks. Version 11.2.1.3.1 of the Oracle Exadata Storage Server software contains an update to version 5.5.

The hardware drivers, notably the OpenFabrics InfiniBand implementation, are GPL-licensed open source. Stacked on top of the infiniband are the Reliable Datagram Socket (RDS) protocol and the proprietary Oracle iDB. This is what Kevin Closson said about it in his interview on our blog:
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I recently reformatted my laptop with the latest Ubuntu LTS release, 10.04, aka Lucid Lynx. Since I like to have a native client installation as well as a portable sandbox server, I decided to install the latest version of Oracle EE, 11.2.0.1.

Rather than re-invent the wheel, I’m going to direct you to the previous Oracle-on-Ubuntu post by my colleague Augusto Bott. Many of the directions there hold true here (even with 32-bit vs 64-bit), with a few exceptions.
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Upgrading to 11g Release Grid Infrastructure? You probably want to read on…

Oracle 11g Release 2 Grid Infrastructure has been dramatically redesigned compare to 10g and 11gR1 Clusterware. Coming with impressive set of new features, Grid Infrastructure also uses much more memory. While RAM is rather inexpensive these days, it does pose an inconvenience in some scenarios. Particularly, for sand-box type installations that I use all the time for my own tests and demonstrations. For production upgrades, you need to be aware of and plan for increased memory usage.

I’ve been able to easily run a 2 node 10g RAC cluster on my MacBook with 4 GB of RAM allocating less than 1 GB of RAM to each virtual machine. That was even enough for a mini database instance with a very small memory footprint. Oracle 11g Release 1 was pretty much the same except maybe the database instance itself required a bit more memory but one node could still fit within 1 GB of RAM.

In 11gR2, bare-bone Grid Infrastructure processes alone consume 10+ times more memory (11.2.0.1 on 32 bit Linux to be precise): Read the rest of this entry . . .

Oracle ASM 11g Release 2 – The Evolution

Oracle Automatic Storage Management has proven to be one of the most widely adopted new features in Oracle Database 10g and it has been dramatically improved in the later 11g releases. This presentation will explain what changes are solved by ASM, how these challenges are solved, what barriers there are to ASM adoptions, and how 11g Release 2 addresses these barriers.

I shall say that the slides alone are not that helpful without my commentary but if you didn’t manage to attend it on one of the previous conferences, we will be releasing it as a webinar soon so stay tuned.