Oracle Real Application Cluster (RAC) is a single database that is shared by multiple Oracle instances. It provides opportunities for improved database availability, performance and scalability. Oracle RAC lowers the TCO of a high-end database and IT assets, since a complex Oracle database can be set-up on low-cost, standard, modular parts. Oracle RAC has matured into a true enterprise, scalable solution, but the adoption curve and skill-set required to maintain RAC is relatively slow, as most organizations who have installed RAC only use it as a two-node cluster.
Introduced in 2008, Toad DBA Suite for Oracle provides a complete solution for DBAs using Oracle Standard Edition, in smaller shops where OEM is not being used or as a complementary solution for DBAs using Oracle Database Enterprise Edition and OEM.
With the Toad DBA Suite for Oracle, DBAs can improve operational efficiency to lower costs by formalizing database management through a systematic approach that assures maintenance, performance and change. The Toad DBA Suite for Oracle allows DBAs to simplify and automate common database administration tasks and become more proactive in solving database-related performance issues before end users are impacted.
Click here for a detailed assessment of Toad DBA Suite for Oracle.
Toad® DBA Suite for Oracle - RAC Edition
The Toad DBA Suite for Oracle – RAC Edition is designed for DBAs and DBA managers to address user productivity and database performance, thus helping to reduce the total cost of ownership of a RAC implementation.
The Toad DBA Suite for Oracle - RAC Edition extends the current capabilities of Toad DBA Suite for Oracle, focuses on the database only and addresses three key areas of database administration:
- Maintenance – managing users and user sessions, database health checks (including security as it relates to user Oracle accounts and permissions), task automation and scheduling, etc.
- Performance Management – real-time performance diagnostics of RAC environments, database and SQL optimization
- Change Management – configuration changes, schema changes, database workload replay testing and benchmark testing of RAC environments
Toad DBA Suite for Oracle - RAC Edition comprises the following components:
- Toad for Oracle Xpert Edition (includes Quest SQL Optimizer for Oracle)
- Benchmark Factory for Databases (Oracle Edition inc RAC)
- Toad Data Modeler
- Spotlight on RAC (seat-based license)
- Spotlight on Windows
- Spotlight on Unix/Linux
The main distinctions between this Suite and the regular Toad DBA Suite for Oracle are the upgraded Spotlight component which enables diagnostics of Oracle RAC and the leveraging of the RAC capabilities of Benchmark Factory for Databases.
There are additional enhancements planned for Toad for Oracle around management of a RAC environment, although there are many windows in Toad which already support RAC.
These include (but not limited to) the connections window, the window connection bars (which indicate connection to RAC), Oracle Parameters, Session Browser, Database Browser (which aggregates metrics across the cluster), Top Session Finder and Database Monitor.
Many of these windows look the same as they would if you were connected to a single instance, but collect data from the GV$ views and include the INST_ID column instead of the V$ views.
Let's start off with RAC performance diagnostics.
Spotlight on RAC's unique user interface provides you with an intuitive, visual representation of the activity on your cluster. Graphical flows illustrate the rate at which data is moving between database components. Icons display the value of key statistics and measurements (metrics).
The power of Spotlight on RAC lies in its ability to quickly isolate bottlenecks in the RAC cluster both at the instance or node level and the overall cluster level. Spotlight monitors at the cluster level because cluster performance will most directly affect the end user’s experience. However it is also important to monitor individual nodes to insure the cluster is operating at peak efficiency. Spotlight quickly tells the DBA:
- How is each RAC node performing?
- How is the cluster as a whole performing?
- Is cluster-specific contention slowing down performance?
A range of drilldowns associated with the alerts provide detailed information to more easily diagnose the root cause of the problem. This information can be viewed on the screen , printed, or copied to a document.
Spotlight on RAC is delivered with best practice thresholds for performance metrics that provide advance warning as condition worsen. But these thresholds can easily be modified to suit your environment and your requirements.
Spotlight on RAC provides a complete view of your Oracle RAC architecture.
Spotlight on RAC showing a 4-node Oracle cluster
If a node on the cluster is experiencing a performance bottleneck (as node 4 is above), clicking on the node will launch Spotlight on Oracle to enable the DBA to quickly diagnose its root cause.
Now let's take a look at load testing your RAC environments.
Benchmark Factory addresses the two key goals of ensuring your RAC environment will perform well under production load - Scalability and Availability.
- Scalability is a relative term, based on a simple rule that as the number of users accessing the system increases, the RAC configuration should be able to handle increased activity.
- Availability is the ability of the system to provide continuous service when one or more of the components in the cluster fail.
Two important criteria used to achieve these goals focus on the cluster being able to load balance across all nodes, and when one or more nodes in the cluster fails, the users failover.
When a node in an Oracle RAC cluster fails, an Oracle database and the remaining nodes continue to run, providing uninterrupted service to users. Oracle RAC distributes database demands across several nodes, performing the function of load balancing. When more capacity is required, additional nodes can be added with minimal effort. Organizations spending time and money setting up a RAC cluster must ensure their systems have the stability to withstand user environment demands when adding nodes.
The Benchmark Factory for Databases component provides the means by which multi-user load (if necessary, thousands of concurrent users) can be applied to your RAC environment based on the well established industry-standard TPC-H and TPC-C benchmarks. Benchmark Factory validates Oracle RAC cluster scalability by using OLTP, database warehousing and mixed workloads. These tests are shipped with Benchmark Factory and a simple-to-use wizard walks you through the necessary steps to begin testing your RAC cluster.
Selecting Oracle RAC Scalability as the required test
The next step of the wizard establishes a connection to the RAC cluster running in a test environment and creates the database objects necessary for the scalability test to proceed. You are then asked to enter a scale factor (which will determine the amount of data to populate the tables) and the number of nodes you wish to test.
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Selecting your scale factor
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Defining the number of nodes to test
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Benchmark Factory allows you to perform a "what-if" analysis to enable you to determine the optimum number of nodes to provide the best all-round performance in production, and, by using Spotlight on Oracle to monitor the test as it is running, the DBA is able to see at what point performance bottlenecks begin to appear.
Another method of testing your RAC environment is to capture and use actual application transactions from production. Benchmark Factory for Databases provides the means to import one or more Oracle Trace files to provide the means to load test the cluster. Oracle tracing can be turned on in either Toad for Oracle or Spotlight on Oracle and will include concurrency between sessions, session activity and latencies that include bind variables.
Benchmark Factory will generate a graphical report which clearly shows the optimal configuration to use.
Benchmark Factory report showing comparative cluster performance
Click here for more information on how to use the Benchmark Factory component to test your Oracle RAC environments, and in particular how to tune the interconnect.
Summary
Despite the advantages of implementing RAC in your environment, there are costs and risks associated with it and it's important to understand what the consequences of those risks are. Deploying RAC introduces additional complexities not present in a single instance environment, such as the interconnect, which requires high levels of DBA experience to effectively manage.
Due to these complexities, most organizations deploy a two-node RAC configuration because they don't know how to anticipate whether a different configuration might be better. For example, if you have 8 CPUs available across your server nodes, is it better to have 2 x 4 CPU nodes or 4 x 2 CPU nodes?
The Toad® DBA Suite for Oracle - RAC Edition gives DBAs the confidence that they are deploying the optimum RAC configuration by enabling them to try out different CPU/node configurations in a test environment. By load testing different configurations in test and using Spotlight on RAC to assess performance in real-time, DBAs can make an informed decision on the best one to deploy in production.
Click here to view a White Paper on Load Testing and Monitoring Oracle Real Application Clusters.