Define Per-Actor Highlight Paths

Question

How should a netdata.topology.v1 producer encode highlight paths when each clicked actor has its own ordered path?

Inputs

• A producer that needs data.presentation.selection.actor_click.mode: highlight_path.
• An actor detail table that stores path rows.
• Actor row references for the clicked actor and every member of its path.

Schema Choices

Use one actor detail table with:

• path_owner_column: optional actor_ref; the actor whose click should use the row.
• path_actor_column: required actor_ref; the actor that appears in the highlighted path.
• path_order_column: required numeric column; the deterministic path order.

Do not point path_actor_column at the owner column unless every actor shares one global path table. For producer-specific per-actor paths, owner and member must be separate columns.

Implementation Steps

1. Define the table type with role: actor_detail, owner: actor, and aggregation: append.
2. Add an owner actor-ref column such as actor.
3. Add a path-member actor-ref column such as path_actor.
4. Add a numeric order column such as path_index.
5. Set data.presentation.selection.actor_click to:

{
  "mode": "highlight_path",
  "path_table": "stream_path",
  "path_owner_column": "actor",
  "path_actor_column": "path_actor",
  "path_order_column": "path_index"
}

Validation

• Validate the payload with FUNCTION_TOPOLOGY_SCHEMA.json.
• Run the topology v1 validator. It checks that owner/member columns are actor_ref and the order column is numeric.
• Add a frontend fixture where two actors have different rows in the same path table, then verify each click resolves only that actor's path.

Gotchas

• The owner column is intentionally optional for backward compatibility and for a single shared global path.
• Reusing the owner column as the path-member column causes each actor click to highlight only itself or direct graph neighbors, because the UI never receives the ordered path members.
• Keep path rows as actor-owned detail data, not graph links. Graph links remain the compact renderable topology; path rows drive selection behavior.