Flash recovery space usage

Job details

Parameters

Job Summary

• Purpose: The purpose of this job is to monitor the usage of the Oracle Flash Recovery Area, ensuring that available space remains within set thresholds to prevent potential outages or performance impacts caused by space constraints.
• Why: This job is important because the Flash Recovery Area (FRA) in Oracle databases is critical for recovery processes such as restoring data from backups and handling RMAN (Recovery Manager) operations. Monitoring its usage helps in proactive system management, reducing the risk of recovery failures due to insufficient space.
• Manual checking: You can check the Flash Recovery Area usage manually in the database by issuing the following SQL command:

select round(sum(percent_space_used)) from v$flash_recovery_area_usage

Technical Details

• Job Identifier: oracle_noschema_flash_recovery_space
• Version: 1.1
• Provider: dbwatch.com
• Category: Capacity
• Entity Type: Scheduled Task
• Compatibility: This job is applicable to Oracle databases, specifically versions 10.2 and higher (including all ‘eleven_and_above’ versions) that do not use a separate engine for this task.
• Installation: The job is marked for express installation given applicable conditions are met.
• Execution Frequency: Every 25 minutes by default.

Monitoring Logic

• SQL Execution: Calculates the cumulative percentage of space used in the Flash Recovery Area by querying the v$flash_recovery_area_usage view.
• Analysis Logic:
  - The script iterates over the query results to determine the used space percentage. – The status is set based on thresholds: if space usage exceeds the ‘used_alarm_threshold’, a critical status (2) is set; if it exceeds the ‘used_warning_threshold’, a warning status (1) is indicated; otherwise, normal status (0) is reported.
• Reactivity: The script changes the reported status immediately based on the space usage, ensuring timely response to potential space utilization issues.

Output Presentation

• Response Actions: Based on the status reported, system administrators can take preemptive actions such as increasing the FRA size, cleanup tasks, or further investigating what is consuming space.
• Scheduled Reporting: Standard interval of monitoring results is every hour by default, according to the embedded dbwatch report template configuration.