Handle db pool errors on appview (#1483)

handle db pool errors on bav

packages/bsky/src/db/db.ts

@@ -41,6 +41,7 @@ export class Database {
       throw new Error(`Postgres schema must only contain [A-Za-z_]: ${schema}`)
     }
 
+    pool.on('error', onPoolError)
     pool.on('connect', (client) => {
       client.on('error', onClientError)
       // Used for trigram indexes, e.g. on actor search
@@ -86,4 +87,5 @@ export class Database {
 
 export default Database
 
+const onPoolError = (err: Error) => dbLogger.error({ err }, 'db pool error')
 const onClientError = (err: Error) => dbLogger.error({ err }, 'db client error')

packages/bsky/tests/db.test.ts

@@ -34,6 +34,17 @@ describe('db', () => {
     await expect(tryKillConnection).rejects.toThrow()
   })
 
+  it('handles pool errors without crashing.', async () => {
+    const conn1 = await db.pool.connect()
+    const conn2 = await db.pool.connect()
+    const result = await conn1.query('select pg_backend_pid() as pid;')
+    const conn1pid: number = result.rows[0].pid
+    conn1.release()
+    await wait(100) // let release apply, conn is now idle on pool.
+    await conn2.query(`select pg_terminate_backend(${conn1pid});`)
+    conn2.release()
+  })
+
   describe('transaction()', () => {
     it('commits changes', async () => {
       const result = await db.transaction(async (dbTxn) => {