Interface: ITaskQueueStats
Properties of a TaskQueueStats.
Implemented by
Properties
approximateBacklogAge
• Optional approximateBacklogAge: null | IDuration
Approximate age of the oldest task in the backlog based on the creation time of the task at the head of the queue. Can be relied upon for scaling decisions.
Special note for workflow task queue type: this metric does not count sticky queue tasks. However, because those tasks only remain valid for a few seconds, they should not affect the result when backlog is older than few seconds.
approximateBacklogCount
• Optional approximateBacklogCount: null | Long
The approximate number of tasks backlogged in this task queue. May count expired tasks but eventually converges to the right value. Can be relied upon for scaling decisions.
Special note for workflow task queue type: this metric does not count sticky queue tasks. However, because those tasks only remain valid for a few seconds, the inaccuracy becomes less significant as the backlog size grows.
tasksAddRate
• Optional tasksAddRate: null | number
The approximate tasks per second added to the task queue, averaging the last 30 seconds. These includes tasks whether or not they were added to/dispatched from the backlog or they were dispatched immediately without going to the backlog (sync-matched).
The difference between tasks_add_rate and tasks_dispatch_rate is a reliable metric for the rate at which
backlog grows/shrinks.
Note: the actual tasks delivered to the workers may significantly be higher than the numbers reported by tasks_add_rate, because:
- Tasks can be sent to workers without going to the task queue. This is called Eager dispatch. Eager dispatch is enable for activities by default in the latest SDKs.
- Tasks going to Sticky queue are not accounted for. Note that, typically, only the first workflow task of each workflow goes to a normal queue, and the rest workflow tasks go to the Sticky queue associated with a specific worker instance.
tasksDispatchRate
• Optional tasksDispatchRate: null | number
The approximate tasks per second dispatched from the task queue, averaging the last 30 seconds. These includes tasks whether or not they were added to/dispatched from the backlog or they were dispatched immediately without going to the backlog (sync-matched).
The difference between tasks_add_rate and tasks_dispatch_rate is a reliable metric for the rate at which
backlog grows/shrinks.
Note: the actual tasks delivered to the workers may significantly be higher than the numbers reported by tasks_dispatch_rate, because:
- Tasks can be sent to workers without going to the task queue. This is called Eager dispatch. Eager dispatch is enable for activities by default in the latest SDKs.
- Tasks going to Sticky queue are not accounted for. Note that, typically, only the first workflow task of each workflow goes to a normal queue, and the rest workflow tasks go to the Sticky queue associated with a specific worker instance.