Telemetry in NetCrunch
Telemetry enables systems to push metrics and logs into NetCrunch without polling. This topic explains when to use telemetry and how NetCrunch supports it via Telemetry Nodes and the OTLP cloud gateway.
What Is Telemetry?
Telemetry is the process of automatically collecting measurements from remote systems and sending them to a central monitoring platform. Unlike traditional polling (e.g., SNMP, WMI), telemetry:
- Is pushed from the source instead of pulled by the server
- Supports real-time streaming of data
- Is ideal for cloud-native, distributed, or event-driven systems
When to Use Telemetry
Telemetry is the right choice when:
- You have systems without direct network visibility (e.g., behind NAT or firewall)
- You want faster alerting or metric freshness
- You’re collecting data from serverless apps, containers, or CI/CD pipelines
- You want to integrate with OpenTelemetry agents, SDKs, or exporters
How NetCrunch Supports Telemetry
NetCrunch implements telemetry collection using two key mechanisms:
1. Telemetry Node
A virtual node type that is used to represent any data endpoint that sends data via REST.
- Anchors incoming metrics or status objects
- Supports JSON/form data payloads
- Accepts data via local REST API or cloud relay endpoint
- Stores received values as counters or alert statuses
- Requires no IP address or discovery
2. OpenTelemetry Gateway (Cloud-Based)
NetCrunch offers native support for OTLP (OpenTelemetry Protocol) for receiving telemetry from OpenTelemetry-compatible agents or exporters.
Supported Endpoints
-
Logs:
https://otlp.netcrunch.io/v1/[serverId]@[sensorId]@[nodeId]/logs -
Metrics:
https://otlp.netcrunch.io/v1/[serverId]@[sensorId]@[nodeId]/metrics
Traces are not currently supported.
How Logs Are Processed
- Received as NetCrunch alerts (with no active state)
- All logs match the default Any Event rule unless filtered
- To filter logs, use the rule:
Event for Received Telemetry Event - Key log fields become alert parameters:
| OTLP Field | Mapped to NetCrunch Parameter |
|---|---|
| log body | message |
| service name | description (if available) |
| attributes | Additional parameters |
How Metrics Are Processed
OTLP metrics are converted to NetCrunch counters using a standardized path model:
| OTLP Metric Element | NetCrunch Counter Path Segment |
|---|---|
| Service or scope name | Object |
| Metric name | Counter |
| Attributes | Instance (joined key=value CSV) |
- Metrics are stored as standard counters
- Description and unit will be added to metadata (feature in progress)
Histogram Support
Histograms will be supported in the future and stored in a dedicated high-volume time-series database.
Currently: not yet implemented.
Summary
Telemetry in NetCrunch enables modern, scalable monitoring for dynamic environments. Whether through the lightweight Telemetry Node or OTLP integration, you can now collect rich logs and metrics from virtually any platform, without needing traditional polling.
- NetCrunch Native Data Formats
Native payload formats used by NetCrunch to ingest external monitoring data as counters, statuses, and contextual data objects using JSON, XML, and CSV.
- Telemetry Node
A Telemetry Node is a NetCrunch node type for receiving metrics, statuses, and events from external systems via REST or OTLP. It anchors telemetry data for cloud, IoT, or custom systems, and replaces the older REST Receiver with a unified, event-capable design.
- Monitoring with Telegraf
Use Telegraf, the open-source metrics agent, to collect from systems NetCrunch does not poll directly and push the results into NetCrunch as ordinary counters and statuses.
- Linux Sysctl Filesystem Monitoring via Telegraf in NetCrunch
This topic explains how to monitor Linux kernel filesystem parameters using Telegraf and send collected metrics to NetCrunch Telemetry Nodes. The Linux Sysctl Filesystem input plugin reads values from the proc sys fs directory and forwards them to NetCrunch using the HTTP output plugin.
- MQTT Telemetry via Telegraf in NetCrunch
This topic explains how to collect system metrics published via MQTT, process them using Telegraf, and forward them to a NetCrunch Telemetry Node endpoint using JSON-based telemetry data.
- SQL Server Monitoring via Telegraf in NetCrunch
This topic explains how to configure Telegraf to collect Microsoft SQL Server metrics and forward them to a NetCrunch Telemetry Node endpoint using JSON-based telemetry data. It covers SQL Server login setup, connection strings, Telegraf input configuration, and supported metric types.
- NetCrunch Databases
NetCrunch uses several specialized databases to efficiently manage configuration, event history, real-time status, long-term metrics, and documentation. Each database is optimized for its specific role in the monitoring platform, allowing NetCrunch to scale from hundreds to thousands of nodes while ensuring high performance.