feat(go/adbc/driver/flightsql): promote safe call headers into FlightSQL spans

[binarycat-dremio]

Summary

Promotes allowlisted adbc.flight.sql.rpc.call_header.* metadata into FlightSQL OpenTelemetry span attributes.

This adds tracing support for safe correlation headers on:

• FlightSQLDatabase.Open
• FlightSQLStatement.Prepare
• FlightSQLStatement.ExecuteQuery
• FlightSQLStatement.ExecuteUpdate

Headers are exposed as attributes like rpc.call_header.x-request-id.

Usage examples

Safe rpc.call_header.* values may be configured at connection level:

with dbapi.connect(
    driver=str(driver),
    entrypoint="FlightSqlDriverInit",
    uri=config.ADBC_URI,
    db_kwargs={
        "adbc.flight.sql.rpc.call_header.x-request-id": "deadbeef-dead-beef-dead-beefdeadbeef",
    },
) as conn:
    ...

or at statement/cursor level:

with conn.cursor(adbc_stmt_kwargs={
    "adbc.flight.sql.rpc.call_header.x-request-id": "req-1",
}) as cur:
    cur.execute("SELECT 1")

cur.adbc_statement.set_options(**{
    "adbc.flight.sql.rpc.call_header.x-request-id": "req-2",
})
cur.execute("SELECT 1")

Why

FlightSQL already sends caller-supplied rpc.call_header.* values on outbound RPCs, but those values were not visible in tracing spans. Surfacing allowlisted correlation headers makes it easier to connect ADBC client spans with upstream request IDs and external traces.

Related

• Issue: Promote safe rpc.call_header.* headers into FlightSQL span attributes #4568
• Discussion: [DISCUSS] FlightSQL tracing: expected relationship between Open, statement/query spans, and connection-level correlation #4572

Closes #4568.

[binarycat-dremio]

cc: @lidavidm you could be interested