mev-beta/docs/IMMEDIATE_ACTIONS_REQUIRED_20251030.md

Immediate Actions Required - MEV Bot

Date: October 30, 2025 Priority: 🔴 URGENT Status: Bot Non-Operational - Multiple Blocking Issues

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🎯 Quick Summary

Swap Detection Fix Status: ✅ Code Complete, ❌ Cannot Test

Blocking Issues:

1. 🔴 Bot hangs at startup (after loading config)
2. 🔴 16,000+ ABI unmarshaling errors (prevents pool data fetching)
3. 🟡 Port conflicts on :9090 and :8080
4. 🟡 56MB error log file

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⚡ IMMEDIATE ACTIONS (Next 30 Minutes)

Action 1: Clean Up Environment (5 minutes)

# Kill all existing bot processes
pkill -9 -f mev-bot

# Clear port conflicts
lsof -ti:9090 | xargs kill -9 2>/dev/null || true
lsof -ti:8080 | xargs kill -9 2>/dev/null || true

# Archive massive error log
cd /home/administrator/projects/mev-beta
mv logs/mev_bot_errors.log logs/archives/errors_pre_fix_$(date +%Y%m%d).log
touch logs/mev_bot_errors.log

Action 2: Debug Startup Hang (15 minutes)

# Run with maximum debug logging and timeout
LOG_LEVEL=debug timeout 45 ./mev-bot start 2>&1 | tee startup_debug_$(date +%H%M).log

# Watch where it hangs
tail -f startup_debug_*.log

# If it hangs, press Ctrl+C and check last log line

Action 3: Test with Minimal Config (10 minutes)

# Disable problematic features temporarily
export METRICS_ENABLED=false
export DASHBOARD_ENABLED=false

# Try starting with HTTP only (no WebSocket)
export ARBITRUM_WS_ENDPOINT=""

# Start bot
timeout 60 ./mev-bot start 2>&1 | tee minimal_test.log

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🔧 PRIMARY ISSUES & FIXES

Issue #1: Bot Startup Hang ⏸️

Symptom:

Loaded environment variables from .env
Using configuration: config/local.yaml (GO_ENV=development)
[HANGS - no further output]

Likely Causes:

• Provider configuration trying to connect to all invalid endpoints
• WebSocket connection attempts timing out
• Contract initialization hanging
• Pool cache file load issue

Quick Diagnostic:

# Check if it's provider-related
strace -e network ./mev-bot start 2>&1 | head -100

# Check if it's file I/O related
strace -e open,read ./mev-bot start 2>&1 | grep -E "\.json|\.yaml"

Potential Fixes:

1. Skip Provider Loading: Comment out provider initialization in cmd/mev-bot/main.go
2. Use Single Endpoint: Only configure one working RPC in .env
3. Disable WebSocket: Set ws_endpoint: "" in config
4. Skip Pool Cache: Rename data/pools.json to force fresh discovery

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Issue #2: ABI Unmarshaling Errors 🔴

Error Pattern:

abi: cannot unmarshal struct { V2Data []struct {...}; V3Data []struct {...} }
in to []datafetcher.DataFetcherV2PoolData

Root Cause: Contract ABI mismatch between deployed contract and Go bindings

Impact: Even with swap detection working, bot cannot fetch pool data for arbitrage calculation

Files to Check:

find . -name "*datafetcher*.go" -type f
# Expected files:
# - pkg/datafetcher/datafetcher.go
# - bindings/datafetcher/datafetcher.go

Fix Options:

Option A: Regenerate Bindings

# If you have the contract ABI
abigen --abi contracts/DataFetcher.abi \
       --pkg datafetcher \
       --out pkg/datafetcher/datafetcher.go

# Then rebuild
go build -o mev-bot ./cmd/mev-bot

Option B: Update Struct Manually

// Find in pkg/datafetcher/ or bindings/datafetcher/
// Change from:
type DataFetcherV2PoolData struct {
    Pool common.Address
    // ...
}

// To:
type DataFetcherBatchResponse struct {
    V2Data []struct {
        Pool             common.Address
        Token0           common.Address
        Token1           common.Address
        Reserve0         *big.Int
        Reserve1         *big.Int
        BlockTimestampLast uint32
        Price0           *big.Int
        Price1           *big.Int
    } `json:"v2Data"`

    V3Data []struct {
        Pool         common.Address
        Token0       common.Address
        Token1       common.Address
        Fee          *big.Int
        SqrtPriceX96 *big.Int
        Tick         *big.Int
        Liquidity    *big.Int
        Price0       *big.Int
        Price1       *big.Int
    } `json:"v3Data"`

    BlockNumber *big.Int `json:"blockNumber"`
    Timestamp   *big.Int `json:"timestamp"`
}

Option C: Disable DataFetcher (Quick workaround)

// In the code that calls DataFetcher, comment out or skip:
// if batchData, err := fetcher.GetPoolData(...); err != nil {
//     // Use fallback: fetch pool data via individual RPC calls
// }

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Issue #3: Port Conflicts 🟡

Error:

listen tcp :9090: bind: address already in use
listen tcp :8080: bind: address already in use

Quick Fix:

# Option A: Kill processes on ports
lsof -ti:9090 | xargs kill -9
lsof -ti:8080 | xargs kill -9

# Option B: Disable metrics/dashboard
export METRICS_ENABLED=false
# Or edit config/local.yaml:
# metrics:
#   enabled: false

Permanent Fix: Add cleanup to bot shutdown:

// In main.go shutdown handler
defer func() {
    metricsServer.Stop()
    dashboardServer.Stop()
}()

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Issue #4: 56MB Error Log 📁

Impact: Disk space, performance, log analysis difficulty

Immediate Action:

# Archive and compress
gzip logs/mev_bot_errors.log
mkdir -p logs/archives
mv logs/mev_bot_errors.log.gz logs/archives/errors_20251030_full.gz
touch logs/mev_bot_errors.log

# This frees up space and allows fresh error tracking

Configure Log Rotation:

# In config/local.yaml or similar
logging:
  max_size: 10MB      # Rotate when file reaches 10MB
  max_backups: 5      # Keep 5 old files
  max_age: 7          # Delete files older than 7 days
  compress: true      # Compress rotated files

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🎯 Testing Sequence (After Fixes)

Once bot starts successfully, follow this sequence:

Step 1: Verify Startup (2 minutes)

./mev-bot start 2>&1 | tee test_startup.log &
BOT_PID=$!

# Wait and check logs
sleep 10
grep -E "Initializing|Creating|Loading" test_startup.log

Expected Output:

[INFO] Loaded environment variables
[INFO] Using configuration: config/local.yaml
[INFO] Initializing components...
[INFO] Creating arbitrage service...
[INFO] Pool discovery system initialized - X pools loaded

Step 2: Verify Pool Discovery Integration (1 minute)

# Look for our fix logs
grep -E "Added.*discovered pools|DEX contract filter" test_startup.log

Expected:

[INFO] 🔧 Adding discovered pools to DEX contract filter...
[INFO] ✅ Added 96 discovered pools to DEX contract filter (total: 116 DEX contracts monitored)
[INFO] ✅ Discovered pools integrated with swap detection system

Step 3: Monitor Swap Detection (5 minutes)

# Watch for swap detection
tail -f test_startup.log | grep -E "DEX transactions|swap.*detected|Block.*Processing"

Expected:

[INFO] Block 395162000: Processing 15 transactions, found 3 DEX transactions
[INFO] Swap detected on pool 0xC6962004f452bE9203591991D15f6b388e09E8D0

Step 4: Check for Errors (ongoing)

# Monitor error log
tail -f logs/mev_bot_errors.log

Should NOT see:

• ❌ ABI unmarshaling errors (if DataFetcher fixed)
• ❌ Port binding errors (if ports cleared)
• ❌ Continuous connection failures

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📊 Success Criteria Checklist

Before considering the bot operational:

• Bot starts without hanging
• No port binding errors
• Pool discovery completes (96 pools)
• Pools integrated with DEX filter (log message visible)
• Blocks being processed
• DEX transactions detected (> 0)
• Swap events found
• No ABI unmarshaling errors in log
• Error log stays under 1MB after 10 minutes

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🔄 Fallback Plan

If bot still won't start after above fixes:

Plan B: Minimal Working Bot

# 1. Use only .env configuration (skip providers.yaml)
# 2. Disable all optional features
# 3. Skip DataFetcher (use direct RPC calls)
# 4. Disable metrics and dashboard
# 5. Use single HTTP endpoint only

Plan C: Staged Component Initialization

// In main.go, comment out sections and add back one at a time:
// 1. Start with just config loading
// 2. Add RPC client
// 3. Add pool discovery
// 4. Add arbitrage service
// 5. Add monitor
// etc.

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📞 What to Report

When asking for help or debugging further, provide:

1. Startup Debug Log:

   LOG_LEVEL=debug ./mev-bot start 2>&1 | head -200 > startup_full.log
   

2. Last Log Line Before Hang:

   tail -5 startup_full.log
   

3. Port Status:

   netstat -tlnp | grep -E ":(9090|8080|443|80)"
   

4. Process Status:

   ps aux | grep mev-bot
   

5. Error Count:

   wc -l logs/mev_bot_errors.log
   tail -50 logs/mev_bot_errors.log
   

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🎯 Priority Order

Do these in order:

1. ✅ Clean environment (ports, logs) - 5 min
2. ✅ Debug startup hang - Find where it stops - 15 min
3. ⏸️ Fix the blocker (likely provider or WebSocket) - 30 min
4. ⏸️ Test with minimal config - Verify bot can start - 10 min
5. ⏸️ Fix ABI mismatch (if needed for pool data) - 1 hour
6. ⏸️ Test swap detection - Verify our fix works - 30 min

Total estimated time to operational: 2-3 hours

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Created: October 30, 2025 20:35 UTC Status: Actionable steps defined Next: Execute cleanup and debug sequence

The swap detection code is ready. These infrastructure issues must be resolved before we can test it.