Bila hifadhidata iliyojibu, hauwezi kutumia JOINs kati ya huduma au miamala ya ACID ya mtu mmoja. Unaunganisha data na kuiweka thabiti kwa kutumia API composition, replicated/CQRS read models, na events.
— mgawanyi anayolingana anaitisha kila huduma na kuunga matokeo:
// build an order view from three services
const order = await ordersApi.get(orderId);
const customer = await usersApi.get(order.customerId); // separate service
const shipment = await shippingApi.get(orderId);
return { ...order, customer, shipment }; // composed in memory
Kwa maswali magumu, zungusha read model (CQRS): huduma hujiandikisha kwa events na kujenga nakala ya ndani iliyofungwa inayoweza kuuliza moja kwa moja.
Orders ─event→ ┐
Users ─event→ ├─▶ [ Order-View service builds its own queryable table ]
Shipping ─event→ ┘
Tumia muundo wa Saga — mlolongo wa miamala ya ndani yenye hatua za kulipiza — badala ya miamala iliyobanwa.
| Njia | Faida | Hasara |
|---|---|---|
| API composition | Sasa sasa | Kusubiri, kufanya kazi nyingi, nyumbufu |
| Nakala ya read model | Kusoma haraka | Hatimaye thabiti |
| Saga | Hakuna 2PC inayohitajika | Ngumu, huhitaji kulipiza |
Usigawanye "tu" jedwali ili kufanya JOIN rahisi — hiyo huunganisha tena huduma. Kubali uthabiti wa mwisho ambapo biashara inaruhusu.
Udhibiti wa data ni mahali ambapo microservices huwa vigumu sana, kwa sababu zana rahisi (joins, transactions) zimeondolewa kwa muundo.
Kuelewa composition, read models, na sagas ndio kinachokuruhusu kuweka huduma huru bila kupoteza usahihi.