Uhamisho mkubwa, hifadhidata mpya, muundo mpya, jukwaa mpya, ni hatari kuu kwa sababu huathiri kila kitu na haileti thamani inayoonekana kwa mtumiaji hadi itakaporedzwa. Njia salama ni ya taratibu na inayoweza kurudishwa nyuma, si kugusa kwa jumla (big-bang cutover). Uhamishaji huzunguka kwa sehemu ambazo unaweza kuangalia na kurudisha nyuma.
Kitabu salama cha uhamisho
1. Know WHY — a migration with no clear payoff isn't worth the risk.
2. Migrate INCREMENTALLY — never flip everything at once.
3. Run OLD and NEW in parallel — strangler-fig pattern.
4. Use feature flags / DUAL WRITES to shift traffic gradually.
5. VERIFY continuously — compare old vs. new outputs (shadow traffic).
6. Keep a ROLLBACK path at every step.
7. Clean up the old system only AFTER the new one is proven.
