X'għandek tikkunsidra meta tibni microservices f'Node?

Question

Accepted Answer

**Microservices** jinqasmu applikazzjoni f'servizzi żgħar, b'mod indipendenti li jistgħu jiġu mdaħħla, li kull waħda tagħmel domnu speċifiku u tikkomunika fuq in-network. In-natura ħafifa ta' Node, li titla' malajr, hija adatta għalihom — imma l-arkitettura tintrodott kumplessità ta' sistemi distribwiti li trid tippjana.

## Monolith vs microservices

```text
Monolith:      one codebase/deployment — simple to build, harder to scale teams
Microservices: many small services — independent deploy/scale, but distributed complexity
```

Microservices itnaddfu s-semplicità in-proċess għal flessibilità operattiva — qiegħa biss meta verament trid skalib/għoti indipendenti jew għandek każat multipli.

## Komunikazzjoni bejn servizzi

```text
Synchronous:  REST / gRPC — direct request/response (simple, but tight coupling + cascading failures)
Asynchronous: message queues (RabbitMQ, Kafka) — events, decoupled, resilient
```

```js
// async/event-driven decouples services — a service publishes an event;
// others react without the publisher knowing/waiting for them
await queue.publish("order.created", { orderId: 123 });
// the email service, inventory service, etc. each consume it independently
```

Agħżel **messaging asinqronu** għal decoupling u resilienza fejn possibbli; sejħat sinqroni huma aktar sempliċi imma jħoloq coupling strett u cascades ta' fallimenti.

## Ħtieġat ċentrali li trid ti-address

```text
✓ Service discovery / API gateway — how services find each other & route external traffic
✓ Data ownership — each service owns its OWN database (no shared DB) → loose coupling
✓ Resilience — timeouts, retries, circuit breakers (a down service shouldn't cascade)
✓ Distributed tracing & centralized logging — debug a request across many services
✓ Eventual consistency — no cross-service transactions; use sagas / events
✓ Authentication — propagate identity (JWT) across service calls
✓ Idempotency — retried messages shouldn't double-process
```

## Eżempju tal-resilienza: circuit breaker

```js
// stop hammering a failing dependency; fail fast and recover gracefully
const breaker = new CircuitBreaker(callPaymentService, { timeout: 3000, errorThreshold: 50 });
breaker.fallback(() => ({ status: "queued" })); // degrade gracefully when it's down
```

## Onestà tat-trade-off

```text
Microservices add real complexity: network failures, distributed debugging, data
consistency, deployment orchestration, more infrastructure. Many apps are better
as a well-structured monolith. Adopt microservices for specific needs, not by default.
```

## Għaliex hija importanti

Microservices huma għażla arkitettewrali kbira b'trade-offs sinifikanti.

Node hija adatta għalihom (ħafifa, startup mgħaġġel), imma l-partijiet diffiċli mhumiex il-kodiċi — huma **ħtieġat ta' sistemi distribwiti**: komunikazzjoni inter-servizzi (ippreferixxu messaging asinqronu għal decoupling), proprietà ta' dejta indipendenti, resilienza (timeouts/retries/circuit breakers biex jipprevjenu cascades ta' fallimenti), osservabbilità (tracing/logging 'il fuq l-servizzi), u konsistenza eventwali.

L-fhim ta' dawn — u r-realtà onesta li microservices iżidu kumplessità li ħafna applikazzjonijiet m'għandhomx bżonn (monolith tajjeb ħafna drabi huwa aħjar) — hija dik li tisseparaw deċiżjoni arkitettewrali ta' qadd minn cargo-culting ta' patern li huwa trending.