node-postgres プールとクエリ Telemetry

import { Pool } from "pg";

async function emitDatabaseOutcome(data) {
  try {
    const delivery = await fetch("https://api.telemetry.sh/log", {
      method: "POST",
      headers: {
        Authorization: process.env.TELEMETRY_API_KEY,
        "Content-Type": "application/json",
      },
      body: JSON.stringify({ table: "database_query_completed", data }),
      signal: AbortSignal.timeout(1000),
    });
    if (!delivery.ok) throw new Error("telemetry_delivery_unconfirmed");
  } catch {
    try { console.warn("Telemetry delivery unconfirmed"); } catch {}
  }
}

const pool = new Pool({ max: 10 });
const SAFE_DATABASE_ERROR_CODES = new Set(["40001", "40P01", "55P03", "57014"]);

function classifyDatabaseError(error) {
  return error && typeof error === "object" &&
    "code" in error &&
    SAFE_DATABASE_ERROR_CODES.has(String(error.code))
    ? String(error.code)
    : "database_error";
}

async function runDatabaseOperation({
  queryFingerprint,
  text,
  values,
}) {
  const acquireStartedAt = performance.now();
  let client;
  let acquisitionWaitMs;
  let queryStartedAt;
  let outcome;

  try {
    client = await pool.connect();
    acquisitionWaitMs = performance.now() - acquireStartedAt;
    queryStartedAt = performance.now();
    const result = await client.query(text, values);
    outcome = {
      query_fingerprint: queryFingerprint,
      service: "checkout-api",
      database_name: "app_production",
      status: "success",
      phase: "query",
      operation_duration_ms: Math.round(performance.now() - acquireStartedAt),
      duration_ms: Math.round(performance.now() - queryStartedAt),
      acquisition_wait_ms: Math.round(acquisitionWaitMs),
      rows_returned: result.rowCount ?? result.rows.length,
      active_connections: pool.totalCount - pool.idleCount,
      idle_connections: pool.idleCount,
      max_connections: pool.options.max ?? 10,
      waiting_count: pool.waitingCount,
      release: process.env.APP_RELEASE,
      environment: process.env.NODE_ENV,
    };
    return result;
  } catch (error) {
    outcome = {
      query_fingerprint: queryFingerprint,
      service: "checkout-api",
      database_name: "app_production",
      status: "failed",
      phase: queryStartedAt === undefined ? "acquire" : "query",
      duration_ms: queryStartedAt === undefined ? undefined : Math.round(performance.now() - queryStartedAt),
      acquisition_wait_ms: Math.round(acquisitionWaitMs ?? (performance.now() - acquireStartedAt)),
      operation_duration_ms: Math.round(performance.now() - acquireStartedAt),
      error_type: classifyDatabaseError(error),
      active_connections: pool.totalCount - pool.idleCount,
      idle_connections: pool.idleCount,
      max_connections: pool.options.max ?? 10,
      waiting_count: pool.waitingCount,
      release: process.env.APP_RELEASE,
      environment: process.env.NODE_ENV,
    };
    throw error;
  } finally {
    client?.release();
    if (outcome) await emitDatabaseOutcome(outcome);
  }
}