Create multiple oracle instances on Same Server

Soofi

Hi All,

We have Linux (Centos) Operating System Server with Oracle DB 11g R2 installed.

We created some 5 schemas in that DB for an APEX application.

Now we have another APEX Application that uses the same Schema Names and DB structure and hosted in another separate server.

Is it possible to host these two Oracle Instances in the same linux based server?

DB will be 11g R2 and APEX version will be 5.

Thanks in advance.

Regards,

Soofi

Mustafa_KALAYCI

Hello,

if I understand you correctly, you will create a new database on the server and this other apex application will be run on the new database, correct? if so yes, 2 different databases on the same server is no problem at all.

Soofi

Thanks for your answer,

In that case Oracle and APEX port numbers will be changed right?

Also about the environment variables and two oracle listeners up and running wont create any issue?

Sunny kichloo

You can have one listener instead of two if it is having Same Oracle Version

One-Listener Support of Multiple Oracle Homes

You can use one listener for spawning connections to databases for multiple Oracle homes. Simply add each system identifier to the SID_LIST section in the ORACLE_BASE\ORACLE_HOME\network\admin\listener.ora file.

Because the SID is unique to a system across different Oracle homes, the listener can spawn the database thread for a specific SID in the correct Oracle home, and the ORACLE_HOME parameter (used in UNIX environments only) is not needed in the listener.ora file.

Source: https://docs.oracle.com/cd/B13789_01/win.101/b10113/orahome.htm

I Know it is of older version but it will give you an idea for your deployment.

JohnWatson2

Soofi wrote:Thanks for your answer,In that case Oracle and APEX port numbers will be changed right?Also about the environment variables and two oracle listeners up and running wont create any issue?

Your http listening port for APEX will be different if you are using the EPG. If you have a more functional solution such as an Apache listener forwarding requests to ORDS deployed to Tomcat, then there is no need for a separate http listening port: only a second DAD managed by the ORDS.

AndrewSayer

Soofi wrote:Thanks for your answer,In that case Oracle and APEX port numbers will be changed right?Also about the environment variables and two oracle listeners up and running wont create any issue?

If you are using EPG for two APEX configurations then yes, you’ll need to use different port numbers to differentiate the two. This is just done as part of your EPG setup. I’m not sure if the same requirement will exist if you are using something like tomcat though, the APEX space is best place to ask.

There’s no problem with multiple databases being registered to the same listener for normal tcp/ip conections - the clients tell the listener which service/SID they want to register to and the listener will take care of the rest.

L. Fernigrini

You can have two separate databases on two separate instances without any problem.

When you move to 12c, 18c or even 19c, you can get benefit of the new architecture that allows pluggable databases, so you can have both DBs on the same instance:

https://oracle-base.com/articles/12c/multitenant-overview-container-database-cdb-12cr1

Mark D Powell

Soofi, you have already been provided your answer for running multiple APEX instances.  I would just like to mention a couple of topic that have not been mentioned so far.  You can run as many Oracle instances on a servers as you have CPU, memory, and IO capacity to handle the load for.  Will the total demand fit on the server, is a question you want to ask and answer before implementing this.  You will need to look at total server memory and divide it up among the OS, PGA, and each instance SGA as needed.  Potentially this may mean you need to reduce the allocation of the existing instance before building the additional one.  This may or may not be a problem as many Oracle instances are over-allocated, that is, the DBA gave the system memory based on what was available and not based on observation of usage under load.

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We have ran as many as 13 RAC instances on a two-node cluster with only 24G of memory while supporting over 400 concurrent sessions to one of the instances so what you want is likely possible and supportable.

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HTH -- Mark D Powell --

Soofi

Hi Mark,

Thanks for your reply.

In my case we have Intel E5 Server - Single Core and the RAM details are mentioned below

With this 8 GB RAM and Oracle Service is already running can we proceed with New Oracle DB installation?

Need suggestions.

Soofi

Thanks for your reply.

I am quite aware of the mutitenant architecture and if I upgrade my db to 12c and created two PDB's, will it be possible to have two different versions of APEX installed on those two PDB's?

Soofi

Hi Sunny,

On the same documentation link the below is mentioned.

Consequences of Setting ORACLE_HOME

If you set ORACLE_HOME in the environment, then software run from another Oracle home will not work reliably. Conflict occurs when you set ORACLE_HOME to point to one Oracle home directory, then attempt to run applications from a second Oracle home. These applications first check for any environment variable settings (such as ORACLE_HOME), before checking the registry through the oracle.key file. Because ORACLE_HOME is set, the applications in the second Oracle home attempt to use files in the first Oracle home, causing a conflict.