EM database Control Using EMCA fails when Service Name contains Hyphen.

When using "emca -config dbcontrol db -repos create -cluster" on a RAC Database the installation of EM database Control fails. Investigation of the logs will see an error in the emca_repos_config_.log

DRCP - Database Resident Connection Pooling

Database Resident Connection Pool (DRCP) is a connection pool in the server that is shared across many clients. Best practice is to use DRCP in connection pools where the number of active connections is fairly less than the number of open connections. DRCP increases Database server scalability and resolves the resource wastage issue that is associated with middle-tier connection pooling. The Database Resident Connection Pool implementation creates a pool on the server side, which is shared across multiple client pools. This significantly lowers memory consumption on the server because of reduced number of server processes on the server and increases the scalability of the Database server.

Oracle 12c Password file management with ASMCMD commands

Now that it is possible to store the Oracle password file inside ASM - Oracle Database 12c. A functionality that helps by RAC databases and cluster, we do not have to manage to keep the files in sync between servers anymore.

 See my other blog posts on this:

• Password File in ASM - Oracle release 12c
• Password file maintenance on Clustered ASM and RAC databases

Are there commands created for ASMCMD to maintain the passwordfile for databases.

Password File in ASM - Oracle release 12c

Prior to Oracle Database 12c, the password file was always located under $ORACLE_HOME/dbs file structure, even for RAC instances and for RAC ASM cluster. For RAC the DBA organisation had to managed to keep the password file in sync on each node. See for a solution in an earlier blog on my site "Password file maintenance on Clustered ASM and RAC databases 11gR2 and before"

Oracle 12c

Now in Oracle 12c, it is possible to store the password file on ASM. Wonderfule this means a shared password file for Oracle RAC databases , it is shared for all instances in the cluster.

Disable the automatic startup of the Oracle Clusterware (CRS|HAS) software

Sometimes, you need for maintenace reasons or others to disable the automatic startup of the Oracle Clusterware software. For that, we use the following commands

crsctl disable/enable has

crsctl disable/enable crs

In some situations, it is interesting, to know in which file the information can be found for  enable/disable of automatic startup of the Oracle Clusterware configuration. The configuration is stored in the repository

11gR2 Clusterware :Oracle Local Registry (OLR)

In 11gR2, Oracle has introduced a new registry to maintain the clusterware resources (css, crs,evm,gip and more) in a new registry called Oracle Local Registry (OLR).
Multiple processes on each node have simultaneous read and write access to the OLR particular to the node on which they reside, regardless of whether Oracle Clusterware is running or fully functional.
By default, OLR is located at Grid_home/cdata/host_name.olr on each node.The OCR still exists, but maintains only the cluster resources.

Until Oracle Database 11gR1, the RAC configurations consisted of just one registry when running Oracle Clusterware. Shortly called OCR, Oracle Cluster Registry, maintained the cluster level resource information, privileges etc. To be precise, the OCR maintained information about 2 sets of node level resources, namely, the Oracle Clusterware Components (CRS, CSS, evm) as well as Cluster resources (DB, Listener etc).

How to Install and Deinstall DBconsole

Step-By-Step - DBconsole RAC Uninstall

WARNING: The uninstall process will Quiesce the database. Do not run on a live system
1. Ensure you have the following information before continuing.

• Database unique name
• Listener port number
• Password for SYS user
• Password for SYSMAN user

2. Log onto any node in the cluster.
3. Set-up your environment

• . oraenv
• ORACLE_SID = [SID] ? enter sid

4. Deconfigure dbconsole and drop the repository

• emca -deconfig dbcontrol db -repos drop -cluster

Creating a Highly Available Environment for APEX Application in an Oracle Real Application Clusters

In Oracle 11g Oracle Application Express (APEX) is now a standard component in the Oracle 11g RDBMS.
The APEX component is intergration with the Oracle Database and ensures that the application builts with Oracle APEX
benefit from the reliability, security, scalability and availability offered by the Oracle database.
Oracle Real Application Cluster (RAC) is recommended for applications that require High Availability (HA), scalability,
and workload management. How can we intergrate the High Availability (HA), scalability,
and workload management functionality to the APEX module in a RAC environment
In this blog I descibe, how to use and configure APEX module in a RAC database environment.
In a normal High Availability for database enviroment is the Oracle HTTP server an unprotected feature by the Oracle Clusterware.