RAC monitoring multiple instances

Monitoring Multiple Databases

Frequently today, DBAs are called upon to manage multiple instances. In this era of corporate downsizing, what was a manageable job a few years ago has rapidly descended into the chaos of a Doom episode gone wrong, as more responsibility is being placed on fewer and fewer people. Thus, it's imperative for DBAs to automate the management of multiple databases, especially if they are physically remote.     

To this end, a DBA has several options. If your budget permits (the tools seem to get more expensive as the hardware decreases in cost), purchase a good monitoring tool, such as Patrol by BMC, or Eco-Tools, as well as a "point-and-shoot" monitor, such as Q by Savant Corporation, Platinum Technologies' offerings, or any of the plethora of new tools that seem to spring up each year. If the budget is not there for purchasing tools or, like me, you are a bit of a masochist, you may want to develop your own tools based on the scripts in this book.      

To develop your own tools, you must first decide what you want to monitor. Once you have, in a central monitoring database, design and install a small set of database tables to store the data, with an identifier and date stamp for each entry. On each of the remote databases, establish a monitoring user that has select privileges against all required tables. Next, establish a database link from the remote databases to the central monitoring instance. On the central monitoring instance, establish a set of monitoring users with a set of synonyms that point to the remote database tables. Finally, set up a group of monitoring jobs that execute the monitoring scripts via the database links and synonyms against the remote databases, and store the results in the results tables. Once the tables are loaded, you can report against them. Procedurized, the steps are:

1. Establish a user on the remote database that has select privilege on the DBA and V$ views and tables you want to monitor.

2. On the central or monitoring database, establish a corresponding monitoring user that has a database link to the remote database monitoring user.

3. Create synonyms that hide the required database link syntax for a select from the monitoring remote user; for example: CREATE SYNONYM galinux_sessions FOR v$sessiongalinux;

4. Once the synonyms are in place in the monitoring database, create a central repository user that can be used to store statistics (this will depend on what you want to trend;  look at the DBA_RUNNING_STATS definition in the DBA_UTILITIES zip file on the Wiley Web site).

5. Use procedures to collect and store information in the central repository for each monitored instance.

6. Generate reports from of the central repository.

The Oracle Enterprise Manager enables remote monitoring for multiple instances.

See Code Depot

www.dba-oracle.com/oracle_scripts.htm