11g R2 and RAC One Node

Hi,
what is realy the advantage and difference between RAC and RAC One Node, since finaly we should switch to another server if a node/instance crashes.
On IT Tips by Burleson Consulting it is said :
What makes Oracle RAC One Node special is that it performs quick clone of the instance to a new node.
Which for me means switch to another server on the RAC.
Thanks for the explanations.

- can be easily extended to multiple nodes.
- you can use "Oracle Restart" which restarts your resources automatically
- suppose you have several rac installation among your single databases you can manage a single node like you do with rac installations
Edited by: Ronny Egner on Sep 28, 2009 4:29 PM

Similar Messages

RAC and RAC One Node on the same server?

Hello all,
Anyone know if having RAC and RAC One Node on the same server is possible, supported, and recommended? Our architecture group is moving towards this configuration as a standard, and I need solid direction about feasability.
Thanks for any help you can provide.
Jack Silvey| CVS Caremark | Executive Advisor, IT Systems | CVS Caremark

Yes you can have the RAC and RAC one on the same cluster. For support and recommendations raise a service request with oracle support

Can RAC and RAC One Node share the same servers ?

Does anyone know if it is possible for RAC and the new 11gR2 RAC One Node to share the same set of physical servers i.e. in effect having 2 clusters sharing the same set of servers ( though you could argue RAC One node is a different type of clustering or even that it is not real clustering at all - more instance transporting ).
Or does standard RAC always require exlusive use of the physical servers it is using as its nodes ?
Any thoughts appreciated
Jim

Jimbo wrote:
Does anyone know if it is possible for RAC and the new 11gR2 RAC One Node to share the same set of physical servers i.e. in effect having 2 clusters sharing the same set of servers ( though you could argue RAC One node is a different type of clustering or even that it is not real clustering at all - more instance transporting ).
Or does standard RAC always require exlusive use of the physical servers it is using as its nodes ?
Hi Jim,
To deploy RAC we need Oracle Grid Infrastructure for a cluster (aka Oracle Clusterware) on top.
What determine if it's Single /RAC /RAC one Node is the Installation of Oracle Database.
So, Oracle Clusterware support on Same Cluster ( RAC/ RAC one Node / Single).
You will need one installation for each Feature.
e.g on Same Cluster
---> Grid Infrastructure GRID_HOME=/u01/app/11.2.0/grid
--->> RAC one Node /ORACLE_HOME = /u01/app/oracle/product/11.2.0/racone_11203
--->> RAC /ORACLE_HOME = /u01/app/oracle/product/11.2.0/rac_11203
--->> SINGLE /ORACLE_HOME = /u01/app/oracle/product/11.2.0/db_11203
For me make no sense RAC ONE NODE and RAC on same cluster.
Because RAC ONE NODE is a RAC with less feature.
Regards,
Levi Pereira

RAC one node license

Hi all,
we are running several rac systems license for EE. So we plan to switch from normal rac EE to "RAC ONE NODE"
Does anyone can tell me if the normal rac license to use "rac one node" or does we need the "rac one node" option ?
Thanks *T

Re,
so that is not really the point.
"RAC" costs around 25k per cpu and "rac one node" around 10 so the question is if we do use "rac one node" instead of lets say "normal rac" Does we can use our current license or does we need to buy new licenses.
RAC costs more....Oracle make benefit :-?
Thanks again
*T

Oracle RAC one node

why Oracle introduced Oracle RAC one node in 11gR2?
I have gone through oracle documents on oracle rac one node, but i couldn't find much added advantage than instance failover. We have already some technologies like datagaurd and some third party softwares for instance failover.
Then why oracle introduced this RAC one node in the new release i.e 11gR2?
What exactly oracle wants to provide from oracle RAC one node?
Thanks...
Bharath

Why RAC one node?
Oracle RAC one node is a single instance of Oracle RAC that runs on the node in a cluster. The benefit of the RAC one node option is that it allows you to consolidate many databases into one cluster without a lot of overhead, while also providing high availbilty benefits of failover protection, as well as for Online rolling patch application and rolling upgrades for the Oracle clusterware.
Another aspect of RAC one node allows you to limit th CPU utilization of individual database instances within the cluster through a feature called resource manager instance caging, which gives you the ability to dynamilcally change the limit as required.
Furhtermore , with RAC one node there is no limitation for server scalabilty such that if applications outgrow the current resources than a single node can supply, you can then upgrade the applications online to Oracle RAC.
In tthe event that the node which is runnig Oracle RAc one node becomes saturated and out of resources, you can migrate the instance to another node in the cluster using Oracle rac one node and another new utilty called OMOTION feature.OMOTION feature for Oracle RAC 11g R2 rac allows you to migrate a running instance to another server without downtime or distrubtion in service for your enviornment.
Hope you're understand.

Oracle Applications 11i Load Balancing does not work with RAC one Node

Hi all,
Could you help me to resolve this issue.
Architecture environment is :
- One APPS tier node
- Two nodes Oracle Database Appliance (Primary node 1 holds INSTANCE_1 et Secondary node is configurured to holds INSTANCE_2), i.e RAC one Node.
- The primary node have instance_name SIGM_1 and the secondary node have instance_name SIGM_2, but in RAC one node, the secondary instance is not alive.
We convert our EBS 11i environment to RAC following note ID Using Oracle 11g Release 2 Real Application Clusters with Oracle E-Business Suite Release 11i [ID 823586.1].
When testing Database failover, Oracle Applications 11i load balancing does not work anymore.
The root cause is that, when the primary node of the Rac one node is down, the INSTANCE_NAME_1 is automaically relocating to the surviving node,.
During test failover, we imagine that when the primary node goes down, the secondary node start or relocate database with instance_name SIGM_2, and in that case the Oracle Applications load balancing works.
Currently, when the primary node goes down, the instance_name SIGM_1 is relocated on the secondary node, which cause failure of Oracle Applications Load Balancing.
Thank you for your advice.
Moussa

This is something I observed a long time ago for Safari (ie: around version 1). I'm not sure this is Safari, per se, but OpenSSL that is responsible for the behavior. I'm pretty sure Chrome does this and I've seen some Linux browsers do it.
What I have done at the last two companies I've worked for is recommend that our clients do not use SSL SessionID as the way of tracking sticky sessions on web servers, but instead using IP address. This works in nearly all cases and has few downsides. The other solution is to use some sort of session sharing on your web servers to mitigate the issue (which also means that your web servers aren't a point of failure for your users' sessions). (One of the products I supported had no session information stored on the web servers, so we could safely round-robin requests, the other product could be implemented with a Session State Server... but in most cases we just used IP address to load balance with). The other solution is to configure your load balancer to terminate the SSL tunnel. You get some other benefits from this, such as allowing your load balancer to reduce the number of actual connections to the web servers. I've seen many devices setup this way.
One thing to consider through this is that - due to the way internet standards work - this really can't be termed a bug on anyone's part. There is no guarantee in the SSL/TLS standards that a client will return the same SSL Session ID for each request and there is not requirement that subsequent requests will even use the same tunnel. Remember, HTTP is a stateless protocol. Each request is considered a new request by the web server and everything else is just trickery to try and get it to work the way you want. You can be annoyed at Safari's behavior, but it's been this way for over 5 years by my count, so I don't expect it to change.

Rac one node in windows 2003?

Hi,
Do RAC one node support windows 2003 64 bit?
I could find neither the patch 9004119 nor documentation for windows.
All are about RAC one node in linux.
Thanks
Vincent

hi,
On 11g R2, yes you can have a one node RAC and the patch you are looking for is only available for Linux. Please read note 220970.1
Salman

Trying out RAC one node on Windows

Hi all,
I have the Grid infrastructure software installed on a 64 bit windows server (standalone - not clustered). Was trying to install an 11g RAC enabled database on said server and it won't install as complains it is not a cluster.
Is it possible to install a RAC enabled Database on a One node grid server that is not clustered to another node?
Any help would be much appreciated as trying to get knowledge with GRID and RAC enabled instances.
Edited by: user13735858 on 10-Feb-2011 06:26

Hi,
Thanks I installed "Real Application Clusters without Oracle Clusterware" for single standalone server - and it installed without issues.Have you installed Oracle RAC without Clusterware?
There is some misunderstanding or you did not install Oracle RAC because Oracle Clusterware is a requirement for using Oracle RAC and it is the only clusterware that you need for most platforms on which Oracle RAC operates.
Although Oracle RAC continues to support select third-party clusterware products on specific platforms, you must also install and use Oracle Clusterware.
Oracle grid infrastructure for a standalone server does not support RAC.
GI Standalone Server is intended to use feature Oracle Restart and Automatic Storage Management (ASM).
The Oracle grid infrastructure for a standalone server is the Oracle software that provides system support for an Oracle database including volume management, file system, and automatic restart capabilities. If you plan to use Oracle Restart or Automatic Storage Management, you must install the grid infrastructure before installing your database.
The grid infrastructure for a standalone server is the software that includes Oracle Restart and Automatic Storage Management. Oracle combined the two infrastructure products into a single set of binaries that is installed as the grid infrastructure home. The grid infrastructure should be installed before installing Oracle Database 11g Release 2.
My question is does the server for one node have to be part of a cluster before you can install a RAC instance, even if you intend the instance to remain as one node RAC?1- You must Install and Configure Oracle Clusterware, even if it is only one node.
2 - Install Oracle Software Database (RAC)
3 - Create your RAC Database.
RAC or RAC One Node must be configured on Oracle Clusterware.
Regards,
Levi Pereira
Edited by: Levi Pereira on Feb 11, 2011 1:15 PM

Oracle RAC one node-11.2.0.1 with patch 9004119

Hi,
I'm slightly stuck here. I have successfully converted 11.2.0.1 2 node RAC to RAC one node with patch *9004119*(which has scripts required for racone). My single instances are up and running, relocation of databases go fine
As i launch my OEM, it pops with +"ORA-12505:TNS:listener does not currently know of SID given in connect descriptor".+ . Obviously, ./Raconeinit renames the DB instances, but doesn't get changed in OEM. It still lists my old instances.
I manually change ORACLE_SID to new instances in all my nodes, so i'm able to connect through sql, but how do i configure it in DB control so that the change is seen universally. Any application i run with the new instance gives me the above mentioned error.
Please respond!

Hi,
In continuation with my above query, i did some search and looked at 'raconeinit' script. It's basically trying to run certain commands to see the current server, free server, current running DB , stores the value in a variable and validates against the input I provide, which is not happening.
When i manually try to run the commands mentioned in script, it gives me invalid -i and -f options errors.
to see DB up:
+./crsctl status resource ora.$LOWER_DB_NAME.db | $GREP -i "^STATE" | $GREP -i "ONLINE" | $WC -l+
to see current server
+./crsctl status resource ora.$LOWER_DB_NAME.db | $GREP -i "STATE" | $AWK -F'ONLINE on ' '{print $2}'+
to see free servers
+./crsctl stat serverpool Free -v|$GREP -i active_servers|$AWK -F'=' '{print $2}'+
It is not accepting my input (free server) and hence exiting. :(
Need help badly

ORA-24544 When Creating a Standby From RAC One Node

I have a RAC One Node database running on node A and am attempting to create a Data Guard standby on node B using the following RMAN command -
duplicate target database for standby from active database
Error returned is -
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of Duplicate Db command at 03/10/2015 11:11:06
RMAN-05501: aborting duplication of target database
RMAN-03015: error occurred in stored script Memory Script
RMAN-04014: startup failed: ORA-24544: Oracle RAC One Node instance is already running.
Can anyone advise ?
Thanks in advance

Hi,
ORA-24544: Oracle RAC One Node instance is already running.
Cause: An instance startup failed because an instance of the Oracle RAC One Node database was already running on one of the cluster nodes.
Action: In Oracle RAC One Node, avoid any attempt to start a second instance by any means while the instance is already running.
I have never used One Node RAC, but it looks like RMAN trying to start an offline instance of current One Node RAC on Node B.
HTH,
Pradeep

RAC One Node: downtime after HW-outage?

Hi ,
RAC One Node seems to be a good alternative compared to a "regular" RAC.
Since we don't have any experience with RAC One Node we are currently going through the available documentaion and try to get a picture of the advantages/disadvantages.
One major point is the question "what will exactly happen when an HW-failure or outage occurs?". It's my understanding - and what Oracle has documented - that the Oracle Clusterware provides failover protection to Oracle RAC One Node. If the node fails, Oracle Clusterware will automatically detect the failure and restart the Oracle RAC One Node database on another server in the pool.
In our case we would have the active node in Datacenter 1, the passive node in Datacenter 2. Therefore if the node in Datacenter 1 fails, the database should then get started on the node in Datacenter 2.
My questions now are:
- will that really automatically be done?
- what happens to the sessions which were connected to the database before the HW-failure?
- is it possible to determine how long this failover will take?
I'm sure that somebody has already tested this situation - any help will be appreciated.
Rgds
JH
Edited by: VivaLaVida on 05.12.2012 08:57

Hi,
My questions now are:
- will that really automatically be done?Yes, automatically and transparent
- what happens to the sessions which were connected to the database before the HW-failure?Depend if you are using Omotion the connection will be redirected to another node, if you are cold failover the client will be have a short downtime.
- is it possible to determine how long this failover will take?Depend of failure, but normal (could failover) is on range from 1 to 3 minutes, using (omotion- hot failover) no downtime.
Read it :
http://www.oracle.com/technetwork/products/clustering/overview/ug-raconenode-2009-130760.pdf?ssSourceSiteId=otncn
Maybe this can clarify your issues.
Any question just ask.
Regards,
Levi Pereira
Edited by: Levi Pereira on Dec 5, 2012 11:58 AM
PS: Ignore use of Omotion if you have "downtime after HW-outage". Consider only cold failover.

Using RAC One Node as a primary database in a Data Guard configuration

Is it possible to use RAC One Node as a primary database in a Data Guard configuration ?
Oracle doc states: "Supports Oracle Data Guard such that you can run physical or logical standby databases on it or even we can NOT run primary databases on it either if the primary databases have DG"
I guess it is not possible but can you folks confirm?
Alessio

Hmmm.... still unclear.
I've submitted a comment which the documentation team should pick up :
"+This sentence : "Supports Oracle Data Guard such that you can run physical or logical standby databases on it or even we can NOT run primary databases on it either if the primary databases have DG"+
+is not very clear.+
+I can understand it upto the words "on it" but the second part of the sentence, beginning with "or even we can NOT ..." seems mangled and unclear.+
+Can you clarify whether RAC One Node can be used as :+
+a. A Primary in a DataGuard configuration+
+b. A Standby in a DataGuard configuration ?+"
Hemant K Chitale

Rac One Node on Rac Servers

Hi Xperts
We have this environment:
2 Rac Nodes 11.2.0.3 Enterprise on Oracle Linux 5.9 .
We have one production Database on this Rac and the users ask to create two single instance on each node, something like this:
Node1 -> Rac Prod1, Single Test
Node2-> Rac Prod2, Single Dev
I want to create Rac One node for those Database (Dev, Test) and create New Diskgroups for ech database.
Can I install a Rac One node on those Server with DBCA?
Do I nedd to Install new Database Software ?
Does the installed Rac have some affectation ?
I just want to be sure about this procedure, before to do anything.
Thank you
J.A.

Hi J.A.
Yes you can! However you need to install Grid Infrastructure (GI) in cluster on both nodes, then install database software. Either during software installation or after that, DBCA would allow you to create 1) Single instance, 2) RAC database, 3) RAC One Node database. Keep in mind that RAC One Node is an option (additional license) to the Enterprise Edition of Oracle Database.
I've talked on that topic at the Bulgarian Oracle Users Group at 2011, here is the link to the presentation, you may find it useful. I might upload the videos as well if you need to have something like a proof of concept of just for your own:
http://sve.to/download/1112/
Also I would go with one disk group for both databases, as long as they share the same physical disks I don't see the point of doing that ? Having one diskgroup would allow you to utilize better you disk/space resources.
The procedure would be:
1. Install GI in cluster.
2. Install software libraries.
3. Patch up to 11.2.0.4.
4. Create RAC One Node database using either command line or using Custom Template of DBCA.
At the end of the day, if you have standard edition license you can still install GI in cluster and create single instance databases on each server. The downside of doing that is that you need to manually failover the database to remaining node in case of disaster.
Regards,
Sve

Patch 9004119 to use Oracle RAC One Node Utilities

Hi all,
I am installing Oracle Grid Infrastructure (11.2.0.3), I am following DOC ug-raconenode-2009-130760.pdf, about RAC One Node installation, as Oracle recomendation, and this DOC talk about install patch 9004119 to use Oracle RAC One Node Utilities (such as Omotion). If I am using 11.2.0.3, is it necessary install patch 9004119 ?
Thanks in advance.
Leonardo.

user10674190 wrote:
Hi all,
I am installing Oracle Grid Infrastructure (11.2.0.3), I am following DOC ug-raconenode-2009-130760.pdf, about RAC One Node installation, as Oracle recomendation, and this DOC talk about install patch 9004119 to use Oracle RAC One Node Utilities (such as Omotion). If I am using 11.2.0.3, is it necessary install patch 9004119 ?
Thanks in advance.
Leonardo.9004119:PATCH FOR RAC ONE NODE SCRIPTS can applied only on 11.2.0.1 , As you are in 11.2.0.3 so no need of it.

Oracle RAC ONE Node ! Inquiry

Hi,
Good Day.
In my understanding Oracle 11gr2 RAC ONE Node "online database relocation" ability can address ONLY "Planned downtime Maintenance window".
I mean in case of any catastrophic event i.e "failover / un-planned downtime" a production downtime window is a Must which it need to restart the failed instance on standby node.
Please comment.
Thanks
M Ahmad

Muhammad Ahmad wrote:
Hi Sharma,
I understand.
but i was talking about downtime windows, in my understanding customer will face downtime window during failover to secondary node or restart on same node 'the time needed to restart database instance' but ONLY for planned maintenance activities 'online database instance relocation' capability can be utilized to relocate database instance to another node without facing any downtime as it uses 'shutdown transactional' apporach..
do you agree with my understanding?Yes..
During failure of Instance it will be restarted (downtime occurs). Is not possible use OMOTION on this case
Using Omotion:
Omotion moves a RAC One Node instance from one server to another—without any downtime
• Use Cases
* Load balancing
* Database + OS patching and maintenance
• Oracle supplied tools control migration
* Services are not accepting connections on both nodes at the same time
* Migrated instance shutdown transactional once services moved
* A maximum of 30 minutes allowed for connections to migrate (then shutdown abort)

11g R2 and RAC One Node

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