Monitoring True Cache with Oracle Enterprise Manager

You can discover, monitor, and manage Oracle True Cache in Oracle Enterprise Manager.

Discovery

You can discover True Caches in Enterprise Manager manually. For details, see Discovering and Adding True Cache in Oracle Enterprise Manager Monitoring Guide.

Monitoring

After discovering and adding the primary database and True Caches, you can use Enterprise Manager to monitor their health and performance.

Monitoring a Primary Database and Its True Caches

If you’ve configured multiple True Caches for a single primary database (a one-to-many setup), you can use Enterprise Manager to view the topology and see a comprehensive overview of the primary database and all its associated True Caches. From the Configuration Topology view, you can navigate to the Home page of a True Cache to view graphs that display the transport lag, apply lag, and hit ratios. This lets you assess how current and efficient the cache is.

Monitoring a True Cache Fleet with the True Caches Dashboard

Starting with Oracle Enterprise Manager 24ai Release 1 Update 11 (24.1.0.11), use the True Caches dashboard to monitor all discovered True Cache targets in your fleet from one place.

To open the dashboard, from the Enterprise menu, select Dashboards, and then select True Caches.

Use the Target Name, Target Status, and Target Version filters to find the targets you need.

Note: You need the VIEW_TARGET privilege on a True Cache target to see its data in the dashboard.

Nodes Tab

The Nodes tab shows each discovered True Cache target, its status, its associated primary database, its target version, and its fatal, critical, and warning incident counts.

Performance Tab

The Performance tab shows transport lag, apply lag, RAM buffer hit ratio, True Cache hit ratio, flash hit ratio, and memory usage for discovered True Cache targets. By default, Actual shows the current metric values.

Select Change (%) to compare the average metric values from the last 60 minutes with values from the same 60-minute period on the previous day.

Enterprise Manager refreshes the metrics on the Performance tab every two hours with the TCFleetHomeMetricRefresh job. If you have Full Job privilege on this job, you can change its schedule.

To change the job schedule:

From the Enterprise menu, select Jobs and Procedures, and then select Job Activity.
Select the TCFleetHomeMetricRefresh job and click Edit.
On the Schedule tab, update the schedule.

Metrics

Enterprise Manager provides standard database performance and usage metrics and key True Cache-specific metrics. True Cache metrics in Enterprise Manager include Database Load, Memory Usage, and True Cache Hit Ratios and Lags. Having these metrics readily available in the user interface enables you to quickly detect performance degradations and lag, and proactively fix issues. For details on the True Cache metrics in Enterprise Manager, see True Cache in Oracle Enterprise Manager Oracle Database Metric Reference Manual.

Performance Hub

Starting with Oracle Enterprise Manager 24ai Release 1 Update 7 (24.1.0.7), you can use Performance Hub in Enterprise Manager to monitor database activity, diagnose issues, and tune queries to improve True Cache performance.

You can use the following Performance Hub features with True Cache:

ASH Analytics: Displays Active Session History (ASH) analytics charts that you can use to explore ASH data. In the ASH Analytics tab, you can select an Average Active Sessions dimension and view the top activity for that dimension for the selected time period.
SQL Monitoring: Displays a table that lists monitored SQL statements by dimensions, such as Last Active Time, CPU Time, Database Time, and so on. The SQL Monitoring tab provides information about SQL statements that are currently running and SQL statements that completed, failed, or were terminated.
SQL History: Provides granular statistics on all the SQL executions in the database. The table in the SQL History tab displays the top 500 executions by completion time along with information such as status, session ID, completion time, duration, SQL ID, SQL plan hash, user name, service, module, action, parallel execution, database time, and SQL text.

For details, see Using Performance Hub to Analyze Database Performance in Oracle AI Database Performance Tuning Guide.