Buffer node configuration

Buffer Node

Overview

The Buffer Node accumulates incoming payloads in a FIFO queue and automatically flushes them when either the item count or the serialized byte footprint crosses a configured threshold. Because the node persists its state between executions, it is well suited for batch processing, load smoothing, and integrating with downstream systems that expect grouped payloads instead of single records.

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Core Functionality

What It Does

Buffer brings structure and resiliency to high-throughput pipelines by enabling:

1. Dual Flush Thresholds
Define Max Count and Max Bytes limits. When either capacity is reached, the node emits the buffered collection through the out output port and resets its internal state.

2. Smart Overflow Handling
Choose how to respond when a single item exceeds Max Bytes: reject it, emit it immediately as a single-item batch, or use the Emit Solo alias for Passthrough behavior.

3. Automatic Item Normalization
Scalar values are wrapped into batches of one, while arrays are flattened into individual entries. Each item is serialized to JSON to determine its byte cost, ensuring predictable sizing regardless of the original payload shape.

4. Stateful Execution
Buffer contents (buffer) and byte totals (total_bytes) persist between runs. Internal locking protects the queue during concurrent executions so multiple workers can interact safely.

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Configuration Reference

Parameters

Parameter	Type	Default	Required	Constraints	Description
Max Count	number	100	No	1--10,000	Item count threshold for auto-flush.
Max Bytes	number	0	No	0--25 MB (0 = disabled)	Size threshold in bytes.
Overflow	select	"reject"	No	reject / passthrough / emitSolo	What happens when a single item exceeds maxBytes.
Mode	select	"collect"	No	collect / sliding	collect: Flush and start fresh. sliding: Sliding window.
Size Field	string	""	No	Expression that returns a number	Dynamic batch size from input data.
Max Size	number	500	No	1--500	Safety cap for dynamic size.

Settings

Setting	Options	Default	Description
Timeout (seconds)	number	Pipeline default	Maximum execution time for this node (1--600).
Retry on Timeout	Pipeline Default / Enabled / Disabled	Pipeline Default	Whether to retry on timeout.
Retry on Fail	Pipeline Default / Enabled / Disabled	Pipeline Default	Whether to retry on failure. When Enabled, shows Advanced Retry Configuration.
On Error	Pipeline Default / Stop Pipeline / Continue Execution	Pipeline Default	Behavior when node fails after all retries.

Advanced Retry Configuration

Only visible when Retry on Fail is set to Enabled.

Field	Type	Default	Range	Description
Max Attempts	number	3	1--10	Maximum retry attempts.
Initial Delay (ms)	number	1000	100--30,000	Wait before first retry.
Max Delay (ms)	number	120000	1,000--300,000	Upper bound for backoff delay.
Multiplier	number	2.0	1.0--5.0	Exponential backoff multiplier.
Jitter Factor	number	0.1	0--0.5	Random jitter.

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Usage Examples

Example 1: Flush 50 Sensor Readings or 256 KB

Field	Value
Max Count	50
Max Bytes	262144
Overflow Mode	reject
Retry on Fail	Enabled
On Error	Continue Execution

The buffer emits as soon as it holds 50 sensor readings or their serialized size exceeds roughly 256 KB, keeping downstream batch APIs within limits.

Example 2: Pass Through Oversized Alerts

Field	Value
Max Count	200
Max Bytes	524288
Overflow Mode	Passthrough
Notes	Large alerts must bypass batching.

Any alert larger than 512 KB is forwarded immediately as a one-item batch, while other payloads continue accumulating until thresholds are met.

Example 3: Inspect Buffer State During a Run

Field	Value
Manual Action	get
Example Response	{ "bufferCount": 37, "totalBytes": 81234, "overflowMode": "reject" }
Display Note in Pipeline	true

Triggering get lets operators view queued orders (e.g., {"id":"A-100","amount":125.4}) without flushing them, confirming that thresholds are tuned correctly.