1. Advanced Management and Monitoring for Engineered Systems
  2. Using the Engineered Systems Packs
  3. Exadata Management Pack Features
  4. I/O Resource Management Advisor

I/O Resource Management Advisor

The Enterprise Manager I/O Resource Management Advisor facilitates effective usage of Exadata I/O Resource Management (IORM) by providing tools to analyze flash I/O utilization across all databases running on an Exadata system and to identify potential measures to optimize system I/O resource usage. It provides the following capabilities:

  • Comprehensive System-Level I/O Overview: Different visualizations at multiple levels, including treemaps, tables and metric charts, provide a comprehensive overview of IORM settings and a summary of I/O utilization across the Exadata system. These visualizations allow identification of any container database (CDB), pluggable database (PDB), or non-container database that is experiencing flash I/O throttling due to system limits or I/O usage by neighboring databases.

  • Detailed Database-Level I/O Analysis: Once a potentially impacted database is identified, additional drill-down visualizations allow analysis of the I/O performance history of a database and its neighbors across multiple dimensions, including I/O utilization, throughput, and latency. Analysis at this level can assist in determining whether a database is actually experiencing throttling and associated performance degradation, and whether its IORM plan needs to be updated.

Topics:

Prerequisites

The following requirements must be met in order to use the I/O Resource Management Advisor:

  • Enable the Exadata Management Pack for the relevant Database Machine and/or Exadata Infrastructure targets.
  • The Oracle Enterprise Manager Exadata plug-in version must be 13.5.1.23 or above on both the Agent and Management Server.
  • Every storage server in the Exadata system must have a software version 21.1.0.0.0 or above.
  • All storage servers in Exadata system should share the same interdatabase IORM plan, and should be discovered in Oracle Enterprise Manager.
  • The Exadata Database Flash Disk I/O Statistics metric must be enabled for the Oracle Enterprise Manager Exadata Storage Server Grid target associated with the Exadata system.

Reference: Concepts

  • Exadata System: Either an on-premises Exadata represented as an Oracle Exadata Database Machine target in Oracle Enterprise Manager or cloud-based Exadata Oracle Exadata Database Service on Cloud@Customer and Oracle Exadata Database Service on Dedicated Infrastructure, both represented by as an Exadata Infrastructure target in Oracle Enterprise Manager.
  • Peak Flash I/O Utilization: The maximum of average I/O utilization for a database or PDB across all its servicing storage servers in the last 24 hours. For example, DB1 is serviced by three storage servers (S1, S2, S3). The average flash I/O utilization of DB1 over the last 24 hours on these 3 storage servers is 50%, 51% and 52% respectively. The peak flash I/O utilization for DB1 in this case is 52%.
  • Flash I/O Utilization Thresholds: The following thresholds are built in to the I/O Resource Management Advisor:
    • Critical: Flash I/O utilization exceeds 75% of database I/O limit
    • Warning: Flash I/O utilization exceeds 50% of database I/O limit
  • Database Flash I/O Limit: The I/O limit for a database as specified in the I/O plan that governs the database, which could be an interdatabase plan (CDBs and non-CDBs) or CDB plan (PDBs). For more information regarding I/O plan concepts, see Managing I/O Plans.

Reference: I/O Limits Calculation

Note the following details about how I/O limits are calculated so that I/O Resource Management Advisor data can be interpreted correctly:

  • Database Flash I/O Limit:
    • If the governing plan flash I/O limit value is 0, the storage server interprets this as there being no restrictions on the I/O usage, and therefore the I/O limit for that database is effectively 100% of the storage server's capacity.
    • If the governing plan flash I/O limit value is a non-zero value, the storage server uses this as the actual limit value.
  • Pluggable Database Flash I/O Limit:
    • If the governing plan flash I/O limit value is 0, the storage server interprets this as there being no restrictions on the I/O usage, and therefore the I/O limit for that database is effectively 100% of the CDB's flash I/O limit.
    • If the governing plan flash I/O limit value is a non-zero value, the storage server uses this as the actual limit value, calculated as a fraction of the CDB flash I/O limit.

Also, I/O Resource Management Advisor focuses on flash I/O utilization only because from Exadata version 19.x and above, IORM plan limits are applicable to flash I/O utilization only. See Using the limit attribute.

Using the I/O Resource Management Advisor

I/O Resource Management Advisor is available for Database Machine and Exadata Infrastructure targets. You can launch it by clicking I/O Resource Management Advisor menu from the Database Machine or Exadata Infrastructure menu.

Whether or not an IORM plan is already in place, the I/O Resource Management Advisor provides valuable insights to assist in managing and optimizing system I/O resources, including the following scenarios:

  • Identify the databases with high I/O utilization and determine whether they need more I/O bandwidth.
  • Identify the databases that consume more I/O than desired so that their consumption can be throttled.
  • Analyze historical I/O resource usage to understand whether periods of high I/O usage are concurrent and possibly causing performance degradation.