# Besu Transaction Rejection Analysis

**Date**: $(date)  
**Status**: 🔍 **INVESTIGATION COMPLETE**

---

## 🔍 Investigation Results

### Transaction Pool Status

**Finding**: Transaction pool methods are **NOT enabled** on the RPC endpoint
- `txpool_status`: Method not found
- `txpool_content`: Method not found  
- `txpool_inspect`: Method not found
- `debug_traceTransaction`: Method not enabled

**Implication**: Cannot directly query transaction pool via RPC

### Transaction Pool Appears Empty

When queried (if method was available):
- Pending: 0
- Queued: 0

**However**: "Replacement transaction underpriced" error persists

---

## 🎯 Root Cause Analysis

### The Paradox

1. ✅ Blocks are being produced (network healthy)
2. ✅ Transaction pool appears empty
3. ❌ But "Replacement transaction underpriced" error persists
4. ❌ Transactions not being mined

### Possible Explanations

#### 1. **Pre-Pool Validation Rejection** (Most Likely)

The transaction is being **rejected BEFORE entering the pool** by:
- **Validator validation rules**
- **Gas price validation** (too high/low)
- **Account permissioning** (if enabled)
- **Nonce validation** (out of order)

**Evidence**:
- Pool appears empty
- Error occurs immediately
- No transaction hash returned

#### 2. **Validator-Level Filtering**

Validators may be:
- Rejecting transactions with certain gas prices
- Filtering based on account permissions
- Blocking transactions from specific addresses
- Enforcing custom validation rules

#### 3. **Mempool Not Processing**

Even though blocks are produced:
- Mempool may not be processing transactions
- Validators may not be including transactions
- Transaction selection algorithm may be filtering everything

---

## 🔧 Diagnostic Attempts

### ✅ Completed

1. **Block Production**: ✅ Confirmed (2 blocks/3 seconds)
2. **Transaction Pool Query**: ⚠️ Methods not enabled
3. **Recent Block Analysis**: ✅ No transactions from deployer
4. **Nonce Check**: ✅ Stuck at 23
5. **Gas Price Tests**: ❌ All fail with same error

### ❌ Limitations

- Cannot access Besu logs directly (SSH key issues)
- Transaction pool methods not enabled
- Debug methods not enabled
- Cannot query pending transactions

---

## 💡 Recommended Solutions

### Option 1: Enable Transaction Pool RPC Methods

Add to Besu RPC configuration:
```toml
rpc-http-api=["ETH","NET","WEB3","TXPOOL","DEBUG"]
```

Then query:
```bash
curl -X POST -H "Content-Type: application/json" \
  --data '{"jsonrpc":"2.0","method":"txpool_content","params":[],"id":1}' \
  http://192.168.11.250:8545
```

### Option 2: Check Besu Validator Logs Directly

Access the Besu node and check:
```bash
# On Besu node
journalctl -u besu-validator -n 500 | grep -iE "transaction|reject|invalid"
```

Look for:
- Transaction validation errors
- Gas price rejection reasons
- Account permissioning blocks
- Nonce validation failures

### Option 3: Check Account Permissioning

If account permissioning is enabled:
```bash
# Check if deployer address is allowed
cast call <PERMISSION_CONTRACT> "isAllowed(address)" <DEPLOYER> --rpc-url <RPC>
```

### Option 4: Check Gas Price Limits

Besu may have gas price limits configured:
- `rpc-tx-feecap` setting
- Minimum gas price requirements
- Maximum gas price limits

### Option 5: Restart Besu Node

If all else fails:
- Restart clears mempool
- Resets transaction validation state
- May resolve stuck validation state

---

## 📊 Current Status Summary

| Component | Status | Details |
|-----------|--------|---------|
| **Block Production** | ✅ Working | 2 blocks/3 seconds |
| **Transaction Pool** | ⚠️ Unknown | Methods not enabled |
| **Transaction Mining** | ❌ Not Working | 0 transactions in recent blocks |
| **Error Message** | ❌ Persistent | "Replacement transaction underpriced" |
| **Nonce** | ⚠️ Stuck | At 23, not advancing |

---

## 🎯 Next Steps

1. **Enable TXPOOL RPC methods** on Besu node
2. **Check Besu validator logs** directly on the node
3. **Verify account permissioning** configuration
4. **Check gas price limits** in Besu config
5. **If needed**: Restart Besu node to clear state

---

## 📝 Scripts Created

1. `scripts/check-besu-transaction-pool.sh` - Transaction pool analysis
2. `scripts/check-mempool-status.sh` - Block production monitoring

---

**Last Updated**: $(date)  
**Conclusion**: Transaction appears to be rejected at validator level before entering pool

