16.20 - TASM I/O Usage Event - Teradata Vantage NewSQL Engine

Teradata Vantage™ NewSQL Engine Release Summary

prodname
Teradata Database
Teradata Vantage NewSQL Engine
vrm_release
16.20
created_date
March 2019
category
Release Notes
featnum
B035-1098-162K

The I/O Usage system event enables customers to monitor bandwidth dynamically to find I/O bottlenecks and determine their scope. Previously, detecting I/O issues required lengthy in-depth analysis. This event monitors the Logical Units (LUNs) of the clique and array type TASM determines are most vulnerable to throughput issues and reacts as their I/O usage nears capacity.

Users can configure the following event criteria:
  • The percentage of targeted LUNs to monitor.
  • The percentage of used bandwidth that triggers the event.
  • The percentage of LUNs that must be at the used bandwidth threshold to trigger the event.
  • Qualification method.
  • Qualification time.
For example:
  • Monitor 10% of targeted LUNs.
  • Trigger the event if 1% of those LUNs are at 80% of their potential bandwidth.
  • Average the data over 10 minutes.

Benefits

  • Helps determine available system resources and overall system status.
  • Aids in performance troubleshooting.

Considerations

  • This event is supported only on systems with supported disk array types.
  • This event supports both on-premises and cloud systems.
  • TDWM automatically adjusts I/O values for systems with Workload Management Capacity on Demand (WM COD). For example, if a system has 75% WM COD (uses ¾ of the system) and bandwidth is exhausted, the I/O Usage event reports usage at 100%. The system is using 100% of the I/O available to it.
  • TDWM does not adjust I/O values for systems with Platform Metering Capacity on Demand (PM COD). DBAs need to adjust bandwidth percentages to reflect the PM COD value. For example, if the PM COD value is 80%, the site needs to react to that 80% threshold as if it were 100%.

Additional Information

For more information, see Teradata Vantage™ Workload Management User Guide, B035-1197 or Teradata® Viewpoint User Guide, B035-2206.