# VMID 2400 Besu Log Analysis - Failed Transactions

**Date**: 2026-01-27  
**VMID**: 2400  
**Service**: besu-rpc.service  
**Node**: ThirdWeb RPC Node

---

## Summary

**No explicit transaction failures found** in the Besu logs. However, several operational issues were identified:

1. ✅ **Transaction Execution**: No transaction execution failures or revert errors detected
2. ⚠️ **Block Import Errors**: Invalid block import error (block #580129) - resolved
3. ⚠️ **Thread Blocking**: Multiple Vertx thread blocking warnings (performance issue)

---

## Findings

### 1. Block Import Error (Historical)

**Date**: 2026-01-03 16:41:08  
**Error Type**: InvalidBlockException  
**Block**: #580129 (0x2aaa4f4809549c5365fa8f1f4944d8c25548027d3680bead3fb726ea6fa7ec55)

```
ERROR | BlockPropagationManager | Error importing pending blocks
org.hyperledger.besu.ethereum.eth.sync.tasks.exceptions.InvalidBlockException: 
Failed to import block: Invalid block at #580129

Invalid block 580129: Optional[Parent block with hash 
0xba5eb16a1cdde02e94955d8bee110760904f8ace38d6e0736d6853043d2cc848 not present]
```

**Analysis**:
- This is a **block import error**, not a transaction failure
- The block was rejected because its parent block was not present in the chain
- This is a normal occurrence during blockchain synchronization
- The error resolved itself as the chain caught up
- **No impact on transaction processing**

### 2. Thread Blocking Warnings (Performance)

**Recent Occurrences**:
- 2026-01-04 11:21:23: Thread blocked for 2243 ms (exceeded 2000 ms limit)
- 2026-01-04 11:35:30: Thread blocked for 5541 ms (exceeded 2000 ms limit)
- 2026-01-04 11:35:30: Thread blocked for 4812 ms (exceeded 2000 ms limit)
- 2026-01-03 16:41:06: Thread blocked for 2887 ms (exceeded 2000 ms limit)
- 2026-01-04 03:34:24: Thread blocked for 2275 ms (exceeded 2000 ms limit)

**Analysis**:
- Vertx event loop threads are being blocked
- This is a **performance warning**, not a transaction failure
- Common causes:
  - Database compaction operations
  - Large block imports
  - Garbage collection cycles
  - High RPC load
- **Impact**: May cause temporary RPC response delays, but does not cause transaction failures

### 3. Transaction Status

**Blocks with Transactions** (from recent logs):
- Block #600,135: 1 transaction (152,064 gas, 0.5% utilization) ✅
- Block #600,158: 1 transaction (152,064 gas, 0.5% utilization) ✅
- Block #600,170: 1 transaction (152,064 gas, 0.5% utilization) ✅
- Block #600,111: 1 transaction (152,064 gas, 0.5% utilization) ✅
- Block #600,078: 1 transaction (152,064 gas, 0.5% utilization) ✅

**Analysis**:
- Transactions are being included in blocks successfully
- No transaction execution failures logged
- No revert errors detected
- Gas usage is normal (152,064 gas per transaction)

---

## Transaction Pool Status

**Method Checked**: `txpool_status`  
**Result**: Method not available (expected - this is an RPC-only node)

**Note**: VMID 2400 is an RPC node and may not expose transaction pool methods. To check pending transactions, query the transaction pool on a validator node or use `eth_getTransactionReceipt` to check transaction status.

---

## Recommendations

### 1. Monitor Thread Blocking

If thread blocking warnings become more frequent:
- Monitor system resources (CPU, memory, disk I/O)
- Consider increasing JVM heap size
- Optimize garbage collection settings
- Review database compaction settings

### 2. Check Transaction Receipts

To verify if transactions are actually failing, check transaction receipts:

```bash
# Check a specific transaction receipt
curl -X POST http://127.0.0.1:8545 \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "method": "eth_getTransactionReceipt",
    "params": ["0x<transaction_hash>"],
    "id": 1
  }'
```

A failed transaction will have:
- `status: "0x0"` (failed)
- `status: "0x1"` (success)

### 3. Monitor Block Import

The block import error was historical and resolved. Monitor for:
- Frequent invalid block errors
- Blocks not being imported
- Chain synchronization issues

---

## Conclusion

✅ **No transaction failures detected** in the Besu logs for VMID 2400.

The errors found are:
1. **Historical block import error** (resolved)
2. **Thread blocking warnings** (performance issue, not transaction failures)

**Next Steps**:
- If you have a specific transaction hash that failed, check its receipt status
- Monitor thread blocking warnings if they become more frequent
- Check transaction receipts directly via RPC to verify transaction execution status

---

**Last Updated**: 2026-01-27
