--- id: wiki-2026-0508-비동기-데이터-관리 title: 비동기 데이터 관리 category: 10_Wiki/Topics status: verified canonical_id: self aliases: [Async Data Management, Server State, Data Fetching] duplicate_of: none source_trust_level: A confidence_score: 0.92 verification_status: applied tags: [frontend, async, react-query, swr, server-state] raw_sources: [] last_reinforced: 2026-05-10 github_commit: pending tech_stack: language: typescript framework: react-query --- # 비동기 데이터 관리 ## 매 한 줄 > **"매 server state 의 client cache 의 separation"**. 매 fetch / cache / sync / invalidate / retry / dedupe 의 7 concerns 의 library 의 delegation — 매 2026 의 TanStack Query (v5) / SWR / RTK Query 의 standard. Custom `useEffect + fetch` 의 anti-pattern. ## 매 핵심 ### 매 server vs client state - **client state**: form input, modal open/close, theme — local, ephemeral. Zustand/useState. - **server state**: 매 remote source of truth — async, stale, shared, cached. TanStack Query. ### 매 7 concerns 1. **Fetch**: HTTP request + abort. 2. **Cache**: key-based store. 3. **Dedupe**: 매 simultaneous request 의 share. 4. **Stale**: time-based freshness. 5. **Background refetch**: window focus, reconnect. 6. **Retry**: exponential backoff. 7. **Invalidate**: mutation 후 refetch. ### 매 query lifecycle ``` fetching → fresh (staleTime) → stale → refetch → fresh ↓ gcTime → garbage collect ``` ## 💻 패턴 ### TanStack Query v5 (React) ```tsx import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'; function UserProfile({ id }: { id: string }) { const { data, isLoading, error } = useQuery({ queryKey: ['user', id], queryFn: ({ signal }) => fetch(`/api/users/${id}`, { signal }).then(r => r.json()), staleTime: 60_000, // 1min fresh gcTime: 5 * 60_000, // 5min cache }); if (isLoading) return ; if (error) return ; return ; } ``` ### Mutation + invalidation ```tsx function useUpdateUser() { const qc = useQueryClient(); return useMutation({ mutationFn: (user: User) => fetch(`/api/users/${user.id}`, { method: 'PUT', body: JSON.stringify(user), }).then(r => r.json()), onSuccess: (_, user) => { qc.invalidateQueries({ queryKey: ['user', user.id] }); qc.invalidateQueries({ queryKey: ['users'] }); }, }); } ``` ### Optimistic update ```tsx useMutation({ mutationFn: toggleTodo, onMutate: async (id) => { await qc.cancelQueries({ queryKey: ['todos'] }); const prev = qc.getQueryData(['todos']); qc.setQueryData(['todos'], (old: Todo[]) => old.map(t => t.id === id ? { ...t, done: !t.done } : t)); return { prev }; }, onError: (_, __, ctx) => qc.setQueryData(['todos'], ctx?.prev), onSettled: () => qc.invalidateQueries({ queryKey: ['todos'] }), }); ``` ### Infinite scroll ```tsx const { data, fetchNextPage, hasNextPage } = useInfiniteQuery({ queryKey: ['posts'], queryFn: ({ pageParam = 0 }) => fetch(`/api/posts?cursor=${pageParam}`).then(r => r.json()), getNextPageParam: (last) => last.nextCursor, initialPageParam: 0, }); ``` ### Suspense mode (React 19) ```tsx const { data } = useSuspenseQuery({ queryKey: ['user', id], queryFn: fetchUser, }); // data 의 always defined — Suspense boundary 의 loading 의 handle ``` ### SWR (lightweight alternative) ```tsx import useSWR from 'swr'; const { data, error, mutate } = useSWR( `/api/users/${id}`, (url) => fetch(url).then(r => r.json()), { revalidateOnFocus: true, dedupingInterval: 2000 } ); ``` ### Server Components data (Next.js 15 / RSC) ```tsx // app/users/[id]/page.tsx — runs on server async function UserPage({ params }: { params: { id: string } }) { const user = await fetch(`https://api/users/${params.id}`, { next: { revalidate: 60, tags: [`user-${params.id}`] } }).then(r => r.json()); return ; } ``` ## 매 결정 기준 | 상황 | Approach | |---|---| | React app | TanStack Query v5 | | Next.js App Router | RSC fetch + Server Actions + tag invalidation | | Redux app | RTK Query (Redux 의 통합) | | 매 minimal bundle | SWR (~5KB) | | 매 GraphQL | Apollo Client / urql | | 매 simple form fetch | native `fetch` + `useState` 의 OK | **기본값**: 매 React + REST → TanStack Query, 매 Next.js → RSC fetch. ## 🔗 Graph - 부모: [[State Management]] · [[Data Fetching Patterns]] - 변형: [[TanStack Query]] · [[SWR]] · [[RTK Query]] · [[Apollo Client]] - 응용: [[Optimistic UI]] · [[Infinite Scroll]] · [[React Server Components]] - Adjacent: [[AbortController]] · [[Request Deduplication]] ## 🤖 LLM 활용 **언제**: cache key design 의 review, invalidation strategy 의 plan, race condition 의 debug. **언제 X**: real-time data (WebSocket/SSE 의 substitute). ## ❌ 안티패턴 - **`useEffect + fetch`**: 매 race condition, 매 no dedup, 매 no cache — 매 library 의 use. - **Global Redux 에 server state**: 매 manual cache management — 매 RTK Query 의 use. - **Polling 의 abuse**: 매 SSE/WebSocket 의 substitute. - **`enabled: !!id` 누락**: 매 undefined 의 fetch — false positive. ## 🧪 검증 / 중복 - Verified (TanStack Query v5 docs, Vercel SWR docs, Next.js 15 data fetching). - 신뢰도 A. ## 🕓 Changelog | 날짜 | 변경 | |---|---| | 2026-05-08 | Phase 1 | | 2026-05-10 | Manual cleanup — TanStack Query v5 + RSC + optimistic update 의 정리 |