afl-whatsup

Status monitoring tool for parallel fuzzing instances

The afl-whatsup script provides a summary of the status of multiple parallel AFL++ fuzzing instances running in distributed mode.

Synopsis

afl-whatsup [options] sync_directory

Description

afl-whatsup scans a sync directory containing multiple fuzzer instances (created with -M/-S flags) and displays aggregate statistics about their performance, findings, and health.

Required Parameters

sync_directory · path · required

Directory containing synchronized fuzzer instances.

afl-whatsup sync/

Options

-s · boolean

Skip details and output summary results only.

afl-whatsup -s sync/

-d · boolean

Include dead (stopped) fuzzer stats in the output.

afl-whatsup -d sync/

-m · boolean

Show minimal stats only.

afl-whatsup -m sync/

-n · boolean

No color output.

afl-whatsup -n sync/

Examples

Basic Status Check

# Check status of parallel fuzzers
afl-whatsup sync/

Output Example

afl-whatsup status check tool for afl-fuzz

Individual fuzzers
==================

>>> fuzzer01 (0 days, 2 hrs) <<<

  Last saved crash : 0 days, 0 hrs, 5 min, 23 sec
  Last saved path  : 0 days, 0 hrs, 0 min, 12 sec
  Pending paths    : 47 faves, 234 total
  Cycles done      : 12
  Corpus count     : 1,234
  Unique crashes   : 5
  Unique hangs     : 0
  Exec speed       : 2,345 execs/sec

>>> fuzzer02 (0 days, 2 hrs) <<<

  Last saved crash : none
  Last saved path  : 0 days, 0 hrs, 0 min, 8 sec  
  Pending paths    : 32 faves, 189 total
  Cycles done      : 11
  Corpus count     : 1,189  
  Unique crashes   : 0
  Unique hangs     : 0
  Exec speed       : 2,123 execs/sec

>>> fuzzer03 (0 days, 2 hrs) <<<

  Last saved crash : 0 days, 1 hrs, 12 min, 45 sec
  Last saved path  : 0 days, 0 hrs, 1 min, 3 sec
  Pending paths    : 28 faves, 156 total  
  Cycles done      : 10
  Corpus count     : 1,156
  Unique crashes   : 2
  Unique hangs     : 1
  Exec speed       : 1,987 execs/sec

Summary stats
=============

  Fuzzers alive         : 3
  Total run time        : 0 days, 6 hours
  Total execs           : 42.3 million
  Cumulative speed      : 6,455 execs/sec
  Pending paths         : 107 faves, 579 total
  Pending per fuzzer    : 35 faves, 193 total (average)
  Crashes found         : 7
  Hangs found           : 1
  Coverage gained       : 0 days, 0 hrs, 0 min, 8 sec ago
  Crashes found         : 0 days, 0 hrs, 5 min, 23 sec ago

Summary Only

afl-whatsup -s sync/

Summary stats
=============

  Fuzzers alive         : 3
  Total run time        : 0 days, 6 hours  
  Total execs           : 42.3 million
  Cumulative speed      : 6,455 execs/sec
  Crashes found         : 7
  Hangs found           : 1

Include Dead Fuzzers

afl-whatsup -d sync/

>>> fuzzer04 (DEAD - 1 days, 3 hrs) <<<

  Last saved crash : 1 days, 2 hrs, 34 min, 12 sec
  Last saved path  : 1 days, 2 hrs, 15 min, 8 sec
  Pending paths    : 15 faves, 92 total
  ...

Use Cases

Monitoring Parallel Fuzzing

# Start multiple fuzzers
afl-fuzz -M fuzzer01 -i seeds -o sync -- ./target @@ &
afl-fuzz -S fuzzer02 -i seeds -o sync -- ./target @@ &
afl-fuzz -S fuzzer03 -i seeds -o sync -- ./target @@ &

# Check status periodically
watch -n 60 'afl-whatsup -s sync'

Automated Monitoring

#!/bin/bash
# monitor.sh - Alert if fuzzing stops

while true; do
  alive=$(afl-whatsup -s sync/ | grep "Fuzzers alive" | awk '{print $4}')
  
  if [ "$alive" -lt 3 ]; then
    echo "Warning: Only $alive fuzzers running!" | mail -s "Fuzzer Alert" [e-mail]
  fi
  
  sleep 300  # Check every 5 minutes
done

Performance Analysis

# Log stats over time
while true; do
  date >> fuzzing_stats.log
  afl-whatsup -s sync/ >> fuzzing_stats.log
  echo "---" >> fuzzing_stats.log
  sleep 3600  # Every hour
done

Finding Stuck Fuzzers

# Check which fuzzers haven't found paths recently
afl-whatsup sync/ | grep -A 5 "Last saved path" | grep "hrs\|days"

# These fuzzers might be stuck or exploring deep paths

Output Fields Explained

Individual Fuzzer Stats

• Runtime - How long this fuzzer has been running
• Last saved crash - Time since last crash was found
• Last saved path - Time since last interesting path was found
• Pending paths - Queue items not yet fuzzed (faves + total)
• Cycles done - Number of complete queue cycles
• Corpus count - Total number of test cases in queue
• Unique crashes - Number of unique crashing inputs found
• Unique hangs - Number of unique hanging inputs found
• Exec speed - Executions per second

Summary Stats

• Fuzzers alive - Number of currently running instances
• Total run time - Aggregate runtime across all fuzzers
• Total execs - Sum of all executions
• Cumulative speed - Combined execution speed
• Pending paths - Total across all fuzzers
• Coverage gained - Time since any fuzzer found new coverage
• Crashes found - Time since any fuzzer found a crash

Integration with Scripts

Parse Output

# Extract specific metrics
CRASHES=$(afl-whatsup -s sync/ | grep "Crashes found" | awk '{print $4}')
SPEED=$(afl-whatsup -s sync/ | grep "Cumulative speed" | awk '{print $4}')

echo "Total crashes: $CRASHES"
echo "Overall speed: $SPEED execs/sec"

Dashboard Integration

# Export to JSON-like format for monitoring tools
afl-whatsup -s sync/ | grep -E "(Fuzzers alive|Total execs|Cumulative speed|Crashes found|Hangs found)" > stats.txt

# Process for Prometheus/Grafana/etc.
python parse_stats.py stats.txt > metrics.json

Comparison with fuzzer_stats

# Individual fuzzer stats file
cat sync/fuzzer01/fuzzer_stats

# vs. afl-whatsup - aggregates all fuzzers
afl-whatsup sync/

Directory Structure

afl-whatsup expects this structure:

sync/
├── fuzzer01/          # Main fuzzer (-M)
│   ├── fuzzer_stats
│   ├── queue/
│   ├── crashes/
│   └── ...
├── fuzzer02/          # Secondary fuzzer (-S)
│   ├── fuzzer_stats  
│   ├── queue/
│   └── ...
└── fuzzer03/          # Secondary fuzzer (-S)
    ├── fuzzer_stats
    └── ...

Tips

Regular Monitoring

# Add to crontab for daily reports
0 9 * * * /path/to/afl-whatsup sync/ | mail -s "Daily Fuzzing Report" [e-mail]

Quick Health Check

# One-liner to check if all fuzzers are running
[ $(afl-whatsup -s sync/ | grep "Fuzzers alive" | awk '{print $4}') -eq 4 ] && echo "OK" || echo "ALERT"

Identifying Best Performers

# Find fuzzer with most crashes
afl-whatsup sync/ | grep -B 5 "Unique crashes" | sort -t: -k2 -n | tail -1

# Find fastest fuzzer  
afl-whatsup sync/ | grep -B 10 "Exec speed" | sort -t: -k2 -n | tail -1

Common Issues

”No fuzzers found"

# Wrong directory - should be sync dir, not individual fuzzer
afl-whatsup sync/fuzzer01  # Wrong
afl-whatsup sync/           # Correct

"Permission denied”

# Need read access to fuzzer_stats files
chmod -R +r sync/

Automation Examples

Restart Dead Fuzzers

#!/bin/bash
# restart_dead.sh

for dir in sync/fuzzer*; do
  name=$(basename "$dir")
  
  # Check if fuzzer is dead (no recent updates to fuzzer_stats)
  if [ $(find "$dir/fuzzer_stats" -mmin +5 | wc -l) -gt 0 ]; then
    echo "Restarting $name..."
    
    # Restart fuzzer
    if [ "$name" = "fuzzer01" ]; then
      afl-fuzz -M "$name" -i - -o sync -- ./target @@ &
    else  
      afl-fuzz -S "$name" -i - -o sync -- ./target @@ &
    fi
  fi
done

Collect Statistics

#!/bin/bash
# collect_stats.sh - Log key metrics over time

timestamp=$(date +"%Y-%m-%d %H:%M:%S")
stats=$(afl-whatsup -s sync/ | grep -E "(Total execs|Cumulative speed|Crashes found)")

echo "$timestamp" >> fuzzing.log
echo "$stats" >> fuzzing.log  
echo "---" >> fuzzing.log

See Also

• afl-fuzz - Main fuzzing engine (see -M/-S options)
• afl-plot - Plot fuzzing progress graphs