Connection terminated due to connection timeout error

Bắt đầu bằng cách xem xét cấu hình TypeORM, pg, Azure Database for PostgreSQL và AKS đã được báo cáo, sau đó so sánh hành vi giữa các SKU Standard_B4ms và Standard_D4as_v5. Điều tra stack trace của connection-timeout và khả năng khác biệt về Azure Accelerated Networking. Được xem là hoàn tất khi xác định được nguyên nhân có thể tái hiện và bản sửa cấu hình hoặc dependency đã được xác minh.

We are using NestJS with TypeORM v0.3.25 and pg v8.11.3

Our TypeOrm config is:

const baseOrmConfig: PostgresConnectionOptions & TypeOrmModuleOptions = {
  type: 'postgres',
  host: process.env.DATABASE_HOST ?? 'localhost',
  port: process.env.DATABASE_PORT !== undefined ? Number(process.env.DATABASE_PORT) : 5432,
  username: process.env.DATABASE_USERNAME ?? 'postgres',
  password: process.env.DATABASE_PASSWORD ?? 'password',
  synchronize: false,
  logging: ['error'],
  autoLoadEntities: true,
  ssl: process.env.DATABASE_HOST !== undefined,
  extra: {
    // setting this to 0 to disable auto-disconnect cspell: disable-next-line
    idleTimeoutMillis: 60_000,
    keepAlive: true,
    keepAliveInitialDelayMillis: 60_000,
    max: 10,
    connectionTimeoutMillis: 30_000, // number of milliseconds to wait for connection
  },
};

We host this service on a Azure Kubernetes Service cluster, and are making connections to an Azure Database for PostgreSQL Flexible Server.

Recently, we upgraded our AKS Node SKUs from Standard_B4ms to Standard_D4as_v5, and started seeing a lot of the foll. error:

Error: Connection terminated due to connection timeout 
  at Client.<anonymous> (/usr/src/app/node_modules/pg-pool/index.js:251:17) 
  at Client.patchedClientConnectCallback (/usr/src/app/node_modules/@opentelemetry/instrumentation-pg/build/src/utils.js:309:12) 
  at /usr/src/app/node_modules/@opentelemetry/context-async-hooks/build/src/AbstractAsyncHooksContextManager.js:50:55 
  at AsyncLocalStorage.run (node:internal/async_local_storage/async_hooks:91:14) 
  at SentryContextManager.with (/usr/src/app/node_modules/@opentelemetry/context-async-hooks/build/src/AsyncLocalStorageContextManager.js:33:40) 
  at SentryContextManager.with (/usr/src/app/node_modules/@sentry/opentelemetry/build/cjs/index.js:1430:24) 
  at Client.contextWrapper [as _connectionCallback] (/usr/src/app/node_modules/@opentelemetry/context-async-hooks/build/src/AbstractAsyncHooksContextManager.js:50:32) 
  at Connection.<anonymous> (/usr/src/app/node_modules/pg/lib/client.js:145:18) 
  at Object.onceWrapper (node:events:632:28) 
  at Connection.emit (node:events:518:28) {   [cause]: Error: Connection terminated unexpectedly 
  at Connection.<anonymous> (/usr/src/app/node_modules/pg/lib/client.js:132:73) 
  at Object.onceWrapper (node:events:632:28) 
  at Connection.emit (node:events:518:28) 
  at Socket.<anonymous> (/usr/src/app/node_modules/pg/lib/connection.js:63:12) 
  at Socket.emit (node:events:518:28) 
  at TCP.<anonymous> (node:net:346:12) 
at TCP.callbackTrampoline (node:internal/async_hooks:130:17) } 

We reverted to using the Standard_B4ms SKU and the errors stopped. However, we do need to upgrade our SKUs. We did not have this error on our setup before this.

Any ideas what could be causing this error, and how we could fix this? The only possible explanation we could have found was that it could be related to Azure Accelerated Networking, but have no proof.