# aiohttp.client_exceptions.ClientConnectionError: Connection pool is full

- **ID:** `python/aiohttp-client-connection-pool`
- **Domain:** python
- **Category:** network_error
- **Verification:** ai_generated
- **Fix Rate:** 80%

## Root Cause

Too many concurrent requests exhausting the connection pool limit of aiohttp.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.7 | active | — | — |
| 3.8 | active | — | — |
| 3.9 | active | — | — |

## Workarounds

1. **** (95% success)
   ```
   sem = asyncio.Semaphore(10); async with sem: await session.get(url)
   ```
2. **** (90% success)
   ```
   conn = aiohttp.TCPConnector(limit=100); async with aiohttp.ClientSession(connector=conn) as session:
   ```

## Dead Ends

- **** — May still be insufficient and can lead to memory issues. (60% fail)
- **** — Creates many sessions, causing resource leaks and performance degradation. (70% fail)