proxmox/docs/archive/root-status-reports/VALIDATOR_TXPOOL_ISSUE_DIAGNOSIS.md

Validator Transaction Pool Issue - Diagnosis

Validators Still Producing Empty Blocks After Configuration

Date: 2025-01-27
Status: 🔴 INVESTIGATING

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Current Situation

✅ Completed

• ✅ Added layered tx-pool configuration to all 5 validators
• ✅ Restarted all validators
• ✅ All validators are active and running

🔴 Still Blocking

• 🔴 Blocks still empty (0 transactions)
• 🔴 Nonce stuck at 13104
• 🔴 Transactions in mempool not being processed

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Possible Root Causes

1. Configuration Not Applied Correctly

Check: Verify tx-pool config is actually in validator config files

Command:

ssh root@192.168.11.10 "pct exec 1003 -- grep -A 3 'tx-pool' /etc/besu/config-validator.toml"

2. Validators Not Connected to RPC

Check: Verify RPC can see validator peers

Command:

cast rpc admin_peers --rpc-url http://192.168.11.211:8545

3. Gas Price Requirements

Issue: Validators may have minimum gas price requirements that transactions don't meet

Check: Verify minimum gas price settings on validators

Possible Fix: Increase gas price in transactions

4. Transaction Pool Not Enabled

Issue: Transaction pool might need to be explicitly enabled

Check: Verify if there are other required settings

5. Network Permissioning

Issue: Account permissioning might be blocking transactions

Check: Verify if account permissioning is enabled and if deployer is allowed

6. Validator Sync Status

Issue: Validators might still be syncing after restart

Check: Monitor validator logs for sync status

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Diagnostic Steps

Step 1: Verify Configuration

# Check all validators have tx-pool config
for vmid in 1000 1001 1002 1003 1004; do
  echo "=== Validator $vmid ==="
  ssh root@192.168.11.10 "pct exec $vmid -- grep -A 3 'tx-pool' /etc/besu/config-validator.toml 2>/dev/null || echo 'NOT FOUND'"
done

Step 2: Check Validator Logs

# Check for errors in validator logs
ssh root@192.168.11.10 "pct exec 1003 -- journalctl -u besu-validator -n 50 --no-pager | grep -i 'error\|warn\|tx\|transaction'"

Step 3: Check Network Connectivity

# Check RPC peer connections
cast rpc admin_peers --rpc-url http://192.168.11.211:8545

# Check validator peer connections
ssh root@192.168.11.10 "pct exec 1003 -- curl -X POST -H 'Content-Type: application/json' --data '{\"jsonrpc\":\"2.0\",\"method\":\"admin_peers\",\"params\":[],\"id\":1}' http://localhost:8545 2>/dev/null | jq"

Step 4: Check Gas Price Settings

# Check if validators have min gas price requirements
ssh root@192.168.11.10 "pct exec 1003 -- grep -i 'gas\|price\|min' /etc/besu/config-validator.toml"

Step 5: Check Account Permissioning

# Check if account permissioning is enabled
ssh root@192.168.11.10 "pct exec 1003 -- grep -i 'permission\|allowlist' /etc/besu/config-validator.toml"

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Next Actions

1. Verify configuration was applied correctly
2. Check validator logs for errors
3. Verify network connectivity (RPC ↔ Validators)
4. Check gas price requirements
5. Check account permissioning settings
6. Monitor validator sync status

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Additional Considerations

Besu Transaction Pool Behavior

• Layered tx-pool is default in Besu 23.10+
• Configuration may need additional settings beyond basic layered options
• Validators may need explicit transaction pool enablement

Network Architecture

• RPC node may not be forwarding transactions to validators
• Validators may not be receiving transactions from RPC
• Network partition between RPC and validators

Consensus Mechanism

• QBFT consensus may have additional requirements
• Validator selection may affect transaction inclusion
• Block production timing may affect transaction processing

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Status: Investigating root cause of empty blocks despite tx-pool configuration.