우선순위 수수료와 컴퓨팅 예산

import { ComputeBudgetProgram } from "@solana/web3.js";

const tx = new Transaction()
  .add(ComputeBudgetProgram.setComputeUnitLimit({ units: 250_000 }))
  .add(ComputeBudgetProgram.setComputeUnitPrice({ microLamports: 50_000 }))
  .add(yourRaydiumSwapIx);

wrap_sol (create_ata + system transfer + sync_native)   ≈ 30,000
CPMM swap_base_input (SPL)                              ≈ 140,000
close_account (unwrap)                                  ≈ 5,000
ComputeBudget instructions                              ≈ 10,000
────────────────────────────────────────────────────────
합계                                                   ≈ 185,000 → 250,000으로 예산

// Helius
const response = await fetch(`https://mainnet.helius-rpc.com/?api-key=${apiKey}`, {
  method: "POST",
  body: JSON.stringify({
    jsonrpc: "2.0",
    id:      "fee-estimate",
    method:  "getPriorityFeeEstimate",
    params: [{
      accountKeys: [poolStatePubkey.toBase58()],
      options:     { priorityLevel: "High" },
    }],
  }),
});
const { result } = await response.json();
const microLamports = result.priorityFeeEstimate;

const fees = await connection.getRecentPrioritizationFees({
  lockedWritableAccounts: [poolStatePubkey],
});

// fees: Array<{ slot, prioritizationFee }>
// 최근 N개 슬롯; 기본값 ~150 슬롯.

const median = percentile(fees.map(f => f.prioritizationFee), 0.5);

풀별 목표: <30s에서 80% 착지율
if current_land_rate < 80%: priorityFee += 10%
if current_land_rate > 95%: priorityFee -= 5%

solana confirm <tx-sig> -v
# "consumed N of M compute units"를 찾고 어떤 명령어가 CU를 소진했는지 확인합니다.

async function submitWithRetry(buildTx, maxAttempts = 5) {
  for (let attempt = 0; attempt < maxAttempts; attempt++) {
    const tx = await buildTx({
      priorityFee: basePriorityFee * Math.pow(1.5, attempt),
      blockhash:   (await connection.getLatestBlockhash()).blockhash,
    });

    try {
      const sig = await connection.sendRawTransaction(tx.serialize(), {
        skipPreflight: attempt > 0,  // 첫 시도 후 건너뛰어 지연 절감
      });

      const result = await connection.confirmTransaction(sig, "confirmed");
      if (result.value.err) {
        // 논리 오류; 재시도하지 않습니다.
        throw result.value.err;
      }
      return sig;

    } catch (e) {
      if (isExpiredError(e)) continue;  // 재시도
      if (isRevertError(e)) throw e;    // 재시도하지 않음; 결정적 실패
      throw e;
    }
  }
  throw new Error("submit: exhausted retries");
}

트랜잭션당 평균 CU:          ~250,000
50th 백분위수 수수료:        ~20,000 마이크로랍포트/CU
트랜잭션당 비용:            250_000 × 20_000 × 1e-6 = 5_000 랍포트 = 5e-6 SOL
일일 비용 (1000 txs):       5e-3 SOL ≈ $200 SOL 기준 $1
월간 비용:                   ~$30