HIGH: Unclosed aiohttp Sessions Cause Resource Leaks #19

New Issue

Koko210 · 2026-02-16T22:39:56+02:00

Koko210 commented

2026-02-16 22:39:56 +02:00

aiohttp sessions are created but not properly closed, leading to resource leaks and connection exhaustion.

Where It Occurs

bot/utils/voice_audio.py - aiohttp.ClientSession() without context manager
bot/stt_client.py - Sessions created without cleanup
cat-plugins/danbooru_client.py - aiohttp sessions not closed
bot/utils/image_generation.py - Potential session leaks

Why This Is a Problem

Resource Leaks: Each unclosed session holds open TCP connections
Connection Exhaustion: OS limits max open file descriptors
Slow Performance: Connection pools remain open
Memory Leaks: Session objects not garbage collected

What Can Go Wrong

Scenario 1: Session Exhaustion After Extended Runtime

Bot runs for 48 hours processing messages
Each message creates new aiohttp session for image generation
Sessions are never closed, connections stay open
After 1000 sessions, OS reaches file descriptor limit (typically 1024)
Next attempt to create session fails with OSError
Bot cannot make HTTP requests, features break

Scenario 2: WebSocket Connection Pool Full

Voice audio streaming creates persistent aiohttp session
Session not closed when user leaves voice channel
Connection pool remains allocated
After 20 voice sessions, connection pool exhausted
New voice users cannot connect
Bot shows error but cannot recover without restart

Proposed Fix

Use async with context managers for all aiohttp sessions. Create APIClient class with session management and close on shutdown.

Severity

HIGH - Unclosed sessions cause resource exhaustion and require bot restart.

Files Affected

bot/utils/voice_audio.py, bot/stt_client.py, cat-plugins/danbooru_client.py, bot/utils/image_generation.py

aiohttp sessions are created but not properly closed, leading to resource leaks and connection exhaustion. ## Where It Occurs - bot/utils/voice_audio.py - aiohttp.ClientSession() without context manager - bot/stt_client.py - Sessions created without cleanup - cat-plugins/danbooru_client.py - aiohttp sessions not closed - bot/utils/image_generation.py - Potential session leaks ## Why This Is a Problem 1. Resource Leaks: Each unclosed session holds open TCP connections 2. Connection Exhaustion: OS limits max open file descriptors 3. Slow Performance: Connection pools remain open 4. Memory Leaks: Session objects not garbage collected ## What Can Go Wrong ### Scenario 1: Session Exhaustion After Extended Runtime 1. Bot runs for 48 hours processing messages 2. Each message creates new aiohttp session for image generation 3. Sessions are never closed, connections stay open 4. After 1000 sessions, OS reaches file descriptor limit (typically 1024) 5. Next attempt to create session fails with OSError 6. Bot cannot make HTTP requests, features break ### Scenario 2: WebSocket Connection Pool Full 1. Voice audio streaming creates persistent aiohttp session 2. Session not closed when user leaves voice channel 3. Connection pool remains allocated 4. After 20 voice sessions, connection pool exhausted 5. New voice users cannot connect 6. Bot shows error but cannot recover without restart ## Proposed Fix Use async with context managers for all aiohttp sessions. Create APIClient class with session management and close on shutdown. ## Severity HIGH - Unclosed sessions cause resource exhaustion and require bot restart. ## Files Affected bot/utils/voice_audio.py, bot/stt_client.py, cat-plugins/danbooru_client.py, bot/utils/image_generation.py

Koko210 referenced this issue from a commit

2026-02-23 13:53:58 +02:00

fix(P3): 3 priority-3 fixes — timezone, decay rounding, rate limiter

Sign in to join this conversation.

1 Participants

Notifications

Due Date

No due date set.

Dependencies

No dependencies set.

Reference: Koko210/miku-discord#19