Currently it is hard for our users to understand what is going on with Flow-Control/Global Parallellism.
Did it hit the limit?
How many messages are waiting because of the limit?
What is the affective Flow-Control Rate/Parallelism/Period ?
We are revising the Flow-Control implementation. The plan is to improve the get flow-control endpoint as a start to help users more
GET /v2/flow-control
Current version:
", "waitlistSize": 123, }">
{
"flowControlKey": "",
"waitlistSize": 123,
}
Improved version:
", // "$" for the messages without flow control. "waitlistSize": 123, "parallelism": 10, // If not exists, it means not limited by parallelism "parallelismCount": 5, // 5 tasks are running in parallel at the moment "rateMax": 10, // If not exists, it means not limited by rate "rateCount" : 4, // 4 tasks are started within the last period "ratePeriod": "1d", "ratePeriodStart": 1708000000 // Unix timestamp when the current rate period started }">
{
"flowControlKey": "", // "$" for the messages without flow control.
"waitlistSize": 123,
"parallelism": 10, // If not exists, it means not limited by parallelism
"parallelismCount": 5, // 5 tasks are running in parallel at the moment
"rateMax": 10, // If not exists, it means not limited by rate
"rateCount" : 4, // 4 tasks are started within the last period
"ratePeriod": "1d",
"ratePeriodStart": 1708000000 // Unix timestamp when the current rate period started
}
To access new fields via SDK -> https://upstash.com/docs/qstash/features/flowcontrol#get-a-single-flow-control-key
There is a special $ wait list on this list that reports the waitlist size for the messages that doesn't have any related flow control key and just waiting for global parallelism.
To access global parallelism info via SDK -> https://upstash.com/docs/qstash/features/flowcontrol#get-global-parallelism
You can access all these via rest api as well here: https://upstash.com/docs/qstash/api-refence/flow-control/list-flow-control-keys
Flow Control tab of QStash Console also shows all these data together with the historic global parallelism graph. And there is more detailed version of global parallelism graph on the Usage tab of the QStash Console.
Fetched April 19, 2026