Queue Node Configuration Guide

What It Does

The Queue Node allows workflows to emit one payload at a time on a timed schedule. It acts as a buffer between fast or bursty inputs and downstream components that require consistent timing. If too many payloads arrive in a short time, the node holds them temporarily and releases them in order at the configured rate.

Step-by-Step: How to Configure the Queue Node

Add the node
- Drag the Queue Node from the Logic panel to your workflow canvas.
Connect upstream sources
- Link one or more nodes that emit payloads to be rate-limited or serialized.
Open configuration
- Double-click the Queue Node to configure its timing and queue settings.

Configuration Fields

Field	Requirement	Description
Node Name*	Required	Logical identifier for this node. Used internally and for reference.
Interval (Seconds)*	Required	Time delay between each emitted payload. Note: Ensure the total time to drain the queue (`interval × number of devices`) is less than the input arrival rate; otherwise, payloads may pass through unqueued.
Maximum Queue Size*	Required	Defines the queue capacity. If the number of incoming payloads exceeds this limit, excess payloads are forwarded immediately without delay.

Output Behavior

Payloads are stored in the order they are received.
Every N seconds (defined by the interval), one payload is emitted.
If the queue is empty, no output is generated.
When incoming rate exceeds drain rate and the queue is full, excess payloads bypass the delay and are passed through immediately.

Example:

If 5 payloads are queued and Interval = 2:

Payload 1 → emitted at t + 0s  
Payload 2 → emitted at t + 2s  
Payload 3 → emitted at t + 4s  
Payload 4 → emitted at t + 6s  
Payload 5 → emitted at t + 8s

If a 6th payload arrives and the queue size is limited to 5, it is forwarded instantly.

Best Practices

Select a queue size that matches expected burst size to avoid unintentional pass-through.
Use an interval aligned with downstream capacity (e.g., chart updates or API limits).
Ensure that the product of interval × queue size is sufficient to handle temporary input surges.
Monitor queue behavior in high-throughput environments to avoid unintended bypass of queued delivery.

Use Cases

Rate-limit payloads going to dashboards, APIs, or email/sms services
Space out output to time-series charts that update every few seconds
Serialize incoming telemetry for ordered archival
Prevent flooding of third-party systems with bursts of sensor data

FAQ

Q: What happens when the queue fills up?

A: Any new payloads beyond the queue size are emitted immediately without delay.

Q: Does the node drop data?

A: No. Payloads are either delayed (if space is available) or passed through immediately.

Q: Can this node emit batches?

A: No. It emits exactly one payload per interval. For batch control, use a different strategy such as a buffer or aggregate node.