OpenTelemetry Signal Viewer (otel-signal-viewer.plugin)

The otel-signal-viewer plugin is a Netdata external plugin that reads, indexes, and visualizes OpenTelemetry logs stored in systemd-compatible journal files written by the otel plugin.

These journal files can also be inspected directly with journalctl. Note that the output will contain logs with remapped field names for systemd-compatibility.

Configuration

Edit the otel-signal-viewer.yaml configuration file using edit-config from the Netdata config directory, which is typically located under /etc/netdata.

bash

cd /etc/netdata # Replace this path with your Netdata config directory
sudo ./edit-config otel-signal-viewer.yaml

Journal

The journal section specifies the directories containing journal files to watch and index. By default, it points to the same directory the otel plugin uses to store OpenTelemetry logs. At least one path must be specified:

yaml

journal:
  paths:
    - "/var/log/netdata/otel/v1"

Cache

The cache section configures the hybrid memory and disk cache used for indexed journal data.

Option	Default	Description
`directory`	`/var/cache/netdata/otel-signal-viewer`	Directory to store the disk-backed cache
`memory_capacity`	`1000`	Number of indexed journal files to keep in memory
`disk_capacity`	`32MB`	Maximum size of the disk-backed cache
`block_size`	`4MB`	Size of individual cache blocks
`workers`	number of CPU cores	Number of background workers for indexing
`queue_capacity`	`100`	Queue capacity for pending indexing requests

yaml

cache:
  directory: "/var/cache/netdata/otel-signal-viewer"
  memory_capacity: 1000
  disk_capacity: "32MB"
  block_size: "4MB"
  # workers: <number-of-CPU-cores>
  queue_capacity: 100

Indexing

The indexing section controls how journal fields are indexed, with limits to prevent unbounded memory growth from high-cardinality fields.

Option	Default	Description
`max_unique_values_per_field`	`500`	Maximum unique values to index per field
`max_field_payload_size`	`100`	Maximum payload size (in bytes) for field values to index

yaml

indexing:
  max_unique_values_per_field: 500
  max_field_payload_size: 100