Graph Element Lifecycle

Flink is the authority for the current telemetry-derived graph. Public output contains nodes and edges, never interactions. A Collector service-graph datapoint is only an input fact from which Flink extracts graph-element contributions.

Contributions

Every accepted datapoint is converted through the generated semantic registry into one contribution for each distinct node and edge it describes. The contributor ID is a deterministic hash of the client, server, connection type, and canonical scalar dimensions. Request and failure datapoints from the same telemetry series therefore reinforce the same contributor.

Several contributors can update the same graph element. Nodes with the same semantic ID are one node, and edges with the same source ID, relationship type, and target ID are one edge. Flink stores no separate interaction state after the contributions have been extracted.

Attribute merging

Optional attributes from different contributors complete one another. For example, one contributor can supply a pod's zone while another supplies its version. The authoritative node contains both.

If contributors provide different values for the same optional attribute, Flink selects the newest observation. Equal timestamps are resolved by the lexicographically smallest contributor ID. When a contributor expires, Flink recomputes from the remaining snapshots, so a value can fall back or disappear. A field remains while at least one active contributor still supplies it.

Metrics

Collector service-graph counters enter Flink as deltas. A semantic dependency edge accumulates service_graph.request.total and service_graph.request.failed.total for its active lifetime. Removing one of several contributors does not subtract historical activity. Removing the final contributor deletes the edge; later recreation starts totals from zero.

Expiry and output

Each element stores independent event-time and processing-time expiry for every contributor. Event time follows telemetry timestamps; processing time guarantees cleanup when input becomes idle. Refreshing a contributor records later expiry timestamps, making callbacks from its older timers harmless. Non-expiring explicit contributions register no timer. Generic Flink state TTL is not used, because silent state cleanup cannot publish lifecycle deletes.

The single element-keyed lifecycle stage emits a complete upsert when merged state changes and a delete only when the final contributor disappears. Consumers apply these commands idempotently and never calculate their own stale timeout.