Arrival Rate Meters (ARMs) are TASM rules that provide a way to regulate the flow of requests admitted by TASM into the system. An ARM rule specifies the maximum number of requests per time unit that TASM will admit into the system. Qualification criteria can be used to target specific types of requests.
TASM’s filter and throttle processing sequence for a SQL request is enhanced to check for ARM. New Workload Management ruleset APIs allow you to automate the creation of a system throttle or arrival rate meter without using Viewpoint Workload Designer.
- Prevents a predictable request surge from flooding the TASM delay queue and impacting service time of subsequent queries.
- Limits resource-intensive requests to a specific rate.
- Prevents you from submitting many extremely complex queries frequently.
- Use arrival rate meters carefully after an evaluation period in warning mode.
For more information, see Teradata Vantage™ - Application Programming Reference, B035-1090 and Teradata Vantage™ - Workload Management User Guide, B035-1197.