fix(web): restore Snowflake usage analytics

apps/web/src/lib/drizzle.test.ts

@@ -1,10 +1,4 @@
-import {
-  pool,
-  db,
-  selectReplicaUrl,
-  selectUsageReplicaUrl,
-  shouldExitOnPoolError,
-} from '@/lib/drizzle';
+import { pool, db, selectReplicaUrl, shouldExitOnPoolError } from '@/lib/drizzle';
 
 describe('drizzle', () => {
   describe('pool', () => {
@@ -112,39 +106,6 @@ describe('drizzle', () => {
       ).toBe('postgres://eu-2');
     });
 
-    it('uses the dedicated usage replica when configured', () => {
-      expect(
-        selectUsageReplicaUrl({
-          primaryUrl,
-          nodeEnv: 'production',
-          usageReplicaUrl: 'postgres://eu-2',
-          fallbackReplicaUrl: 'postgres://eu-1',
-        })
-      ).toBe('postgres://eu-2');
-    });
-
-    it('falls back to the standard replica when the usage replica is unset', () => {
-      expect(
-        selectUsageReplicaUrl({
-          primaryUrl,
-          nodeEnv: 'production',
-          usageReplicaUrl: undefined,
-          fallbackReplicaUrl: 'postgres://eu-1',
-        })
-      ).toBe('postgres://eu-1');
-    });
-
-    it('uses the primary for usage reads in local development', () => {
-      expect(
-        selectUsageReplicaUrl({
-          primaryUrl,
-          nodeEnv: 'development',
-          usageReplicaUrl: 'postgres://eu-2',
-          fallbackReplicaUrl: 'postgres://eu-1',
-        })
-      ).toBe(primaryUrl);
-    });
-
     it('falls back to the primary when the regional replica is unavailable', () => {
       expect(
         selectReplicaUrl({

apps/web/src/lib/drizzle.ts

@@ -68,48 +68,21 @@ export function selectReplicaUrl({
 /**
  * Get the read replica URL based on deployment region.
  * - US deployments use the US replica (POSTGRES_REPLICA_US_URL) for lower latency
- * - EU deployments use POSTGRES_REPLICA_EU_URL. POSTGRES_REPLICA_EU_URL_2 is
- *   reserved for usage-analytics scans so those queries stay off this pool.
+ * - EU deployments randomly select one of two EU replicas to split read traffic
+ *   across ~2,200 concurrent Vercel instances (~50/50 statistical distribution)
  * - Falls back to primary if no replica URL is configured for the region
  */
 function getReplicaUrl(): string {
   if (NODE_ENV === 'development') return postgresUrl;
-  const euReplicaUrl = getEnvVariable('POSTGRES_REPLICA_EU_URL');
   return selectReplicaUrl({
     primaryUrl: postgresUrl,
     nodeEnv: NODE_ENV,
     vercelRegion: VERCEL_REGION,
     usReplicaUrl: getEnvVariable('POSTGRES_REPLICA_US_URL'),
-    euReplicaUrls: euReplicaUrl ? [euReplicaUrl] : [],
-  });
-}
-
-/**
- * Replica used by /usage analytics. Always POSTGRES_REPLICA_EU_URL_2 in
- * production so heavy microdollar_usage scans do not compete with ordinary
- * readDb traffic. Falls back to the standard replica, then primary.
- */
-export function selectUsageReplicaUrl({
-  primaryUrl,
-  nodeEnv,
-  usageReplicaUrl,
-  fallbackReplicaUrl,
-}: {
-  primaryUrl: string;
-  nodeEnv: string | undefined;
-  usageReplicaUrl: string | undefined;
-  fallbackReplicaUrl: string;
-}): string {
-  if (nodeEnv === 'development') return primaryUrl;
-  return usageReplicaUrl || fallbackReplicaUrl;
-}
-
-function getUsageReplicaUrl(): string {
-  return selectUsageReplicaUrl({
-    primaryUrl: postgresUrl,
-    nodeEnv: NODE_ENV,
-    usageReplicaUrl: getEnvVariable('POSTGRES_REPLICA_EU_URL_2'),
-    fallbackReplicaUrl: getReplicaUrl(),
+    euReplicaUrls: [
+      getEnvVariable('POSTGRES_REPLICA_EU_URL'),
+      getEnvVariable('POSTGRES_REPLICA_EU_URL_2'),
+    ].filter(Boolean) as string[],
   });
 }
 
@@ -148,35 +121,13 @@ const replica = usesSeparateReplica
   : primary;
 const replicaPool = replica.pool;
 
-const usageReplicaUrl = getUsageReplicaUrl();
-export const usesDedicatedUsageReplica =
-  usageReplicaUrl !== postgresUrl && usageReplicaUrl !== replicaUrl;
-
-const usageReplica = usesDedicatedUsageReplica
-  ? createDrizzleClient({
-      connectionString: usageReplicaUrl,
-      poolConfig: {
-        ...sharedPoolConfig,
-        max: 2,
-        application_name: `${appName}-usage-replica`,
-      },
-      logger: !!DEBUG_QUERY_LOGGING,
-    })
-  : usageReplicaUrl === replicaUrl
-    ? replica
-    : primary;
-const usageReplicaPool = usageReplica.pool;
-
 // Attach pools to ensure idle connections close before suspension
 // Skip in test environment as it interferes with Jest's cleanup
 if (process.env.NODE_ENV !== 'test') {
   attachDatabasePool(pool);
   if (usesSeparateReplica) {
     attachDatabasePool(replicaPool);
   }
-  if (usesDedicatedUsageReplica) {
-    attachDatabasePool(usageReplicaPool);
-  }
 }
 
 /**
@@ -223,15 +174,6 @@ if (usesSeparateReplica) {
   });
 }
 
-if (usesDedicatedUsageReplica) {
-  usageReplicaPool.on('error', (err: Error) => {
-    console.error('Unexpected error on idle client (usage-replica)', err);
-    if (shouldExitOnPoolError('replica')) {
-      process.exit(-1);
-    }
-  });
-}
-
 // Pool observability is handled centrally by /api/cron/db-pool-metrics,
 // which scrapes PgBouncer metrics from the Supabase Prometheus endpoint
 // for all databases (primary + replicas) every minute.
@@ -254,13 +196,6 @@ const primaryDb = primary.db;
  */
 export const readDb = replica.db;
 
-/**
- * Read replica reserved for /usage analytics scans.
- * Points at POSTGRES_REPLICA_EU_URL_2 in production so those queries do not
- * share the standard readDb pool. Falls back to readDb, then primary.
- */
-export const usageReadDb = usageReplica.db;
-
 /**
  * Default database instance - connects to the primary database.
  * Use this for writes and for reads that need strong consistency.
@@ -290,9 +225,6 @@ export async function closeAllDrizzleConnections(): Promise<void> {
   if (usesSeparateReplica) {
     await replicaPool.end();
   }
-  if (usesDedicatedUsageReplica) {
-    await usageReplicaPool.end();
-  }
 }
 
 export type DrizzleTransaction = Parameters<Parameters<typeof db.transaction>[0]>[0];