1. Uplink Configuration Structure

Located at config.uplink:

• enabled: Master switch (Default true)
• producer: Producer parameters (compression/batching)
• Event mapping: deviceConnected/deviceDisconnected/telemetry/attributes

Each mapping:

Field	Description
topic	Pulsar topic template (Handlebars)
key	partition_key template (Handlebars), if empty not set
payload	EnvelopeJson/Kv/TimeseriesRows/MappedJson

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2. Default topic/key

• topic: persistent://public/default/ng.uplink.{{event_kind}}.{{device_name}}
• key: {{device_id}}

Template syntax see:

• Template Syntax (Handlebars)
• Template Variable Table

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3. Producer Parameters

Field	Default	Description
compression	lz4	none/lz4/zlib/zstd/snappy
batchingEnabled	true	Whether to enable batching (Default off, avoid "Latency/Order" surprise for new users)
batchingMaxMessages	1000	Effective when batching enabled
batchingMaxBytes	131072	Effective when batching enabled (128KiB)
batchingMaxPublishDelayMs	10	Effective when batching enabled

TIP

Recommend enabling batching for high throughput scenarios; keep off or reduce publish delay for low latency scenarios.

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4. Properties and Event Time

Pulsar uplink will:

• partition_key: From rendered key
• properties: Carry RenderContext key-values (For diagnosis/filtering)
• event_time: Use millisecond timestamp (Telemetry/Attributes use collection time)