We’re excited to announce support for monitoring Real Application Clusters (RAC) in Oracle Cloud Infrastructure (OCI) Database Management service for on-premises databases. This feature allows you to have a single view of the cluster database performance across the fleet and drill down to a single cluster.
Database Management now supports monitoring of RAC databases, enabling customers to make informed decisions about how to increase the database throughput and reduce database response time, under increasing workloads by adding more compute network and storage resources from a database perspective.
The critical compute resources in a cluster database are CPU and memory. The RAC-aware fleet dashboard in Database Management helps the database administrator identify databases contending for these critical resources. You can select the RAC instance check box in the performance load map view of the fleet dashboard page to display the available performance data for the fleet of clustered database instances within or across compartments.
Figure 1: Fleet Dashboard with RAC instances
You can monitor database instance-specific details from the Instances tab of the Database Summary page to monitor the following metrics:
Database time and average active sessions
IO throughput and bandwidth
From the top section of the summary page, you can monitor the open status of the database regarding all the instances in the cluster database. This capability helps you spot the instances where the pluggable databases are open.
Figure 2: Instances tab of the Database Summary page
Oracle RAC allows customers to easily scale analytics workloads by eliminating the need for replica databases and database level conflict resolution, significantly improving database administrator productivity. Oracle RAC Cache Fusion is a component of Oracle RAC responsible for synchronizing the caches among Oracle RAC instances, making it possible for applications to seamlessly utilize the computing resources of all the Oracle RAC instances, without making any changes. Cache Fusion utilizes a dedicated private network for cache synchronization.
Application scalability, therefore, relies on the latency and bandwidth provided by the underlying private network. Heavy access to the same data block by multiple database instances leads to high traffic of the data transfer over the interconnect. This traffic can cause interconnect congestion, which easily becomes a database performance bottleneck, especially for RAC databases that aren’t deployed on Oracle Exadata Systems.
You can monitor the interconnect traffic and RAC cluster wait events on the Cluster Cache page from the Resources section of the managed database details page.
Figure 3: Cluster Cache page in Managed Database Details page
Harnessing the power of clusters offers obvious advantages. With Real Application Clusters, you can scale applications to meet increasing data processing demands without changing the application code. As you add resources, such as nodes or storage, Real Application Clusters extends the processing powers of these resources beyond the limits of the individual components. Database Management provides a simple unified fleet view across databases, complex cluster environments and helps to troubleshoot application problems.