[Bug]: Runtime error from Redis when multiple sessions exist

[madhav165]

🐞 Bug Summary

When multiple sessions are connected to gateway, we get a Runtime error.

readuntil() called while another coroutine is already waiting for incoming data

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🧩 Affected Component

Select the area of the project impacted:

• mcpgateway - API
• mcpgateway - UI (admin panel)
• mcpgateway.wrapper - stdio wrapper
• Federation or Transports
• CLI, Makefiles, or shell scripts
• Container setup (Docker/Podman/Compose)
• Other (explain below)

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🔁 Steps to Reproduce

1. Create two sessions at the same time
2. Second session gets errors as above

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🤔 Expected Behavior

Multiple sessions should be supported

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📓 Logs / Error Output

INFO  [mcpgateway.cache.session_registry] Cleaned up pubsub for session 0cc79086-2885-46a0-8ac7-79a0f1b3451a
ERROR [asyncio] Task exception was never retrieved
future: <Task finished name='Task-106' coro=<SessionRegistry.respond() done, defined at /app/mcpgateway/cache/session_registry.py:517> exception=RuntimeError('readuntil() called while another coroutine is already waiting for incoming data')>
Traceback (most recent call last):
  File "/app/mcpgateway/cache/session_registry.py", line 548, in respond
    async for msg in self._pubsub.listen():
  File "/app/.venv/lib64/python3.11/site-packages/redis/asyncio/client.py", line 1097, in listen
    response = await self.handle_message(await self.parse_response(block=True))
                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.venv/lib64/python3.11/site-packages/redis/asyncio/client.py", line 984, in parse_response
    response = await self._execute(
               ^^^^^^^^^^^^^^^^^^^^
  File "/app/.venv/lib64/python3.11/site-packages/redis/asyncio/client.py", line 964, in _execute
    return await conn.retry.call_with_retry(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.venv/lib64/python3.11/site-packages/redis/asyncio/retry.py", line 71, in call_with_retry
    return await do()
           ^^^^^^^^^^
  File "/app/.venv/lib64/python3.11/site-packages/redis/asyncio/connection.py", line 594, in read_response
    response = await self._parser.read_response(
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.venv/lib64/python3.11/site-packages/redis/_parsers/resp2.py", line 82, in read_response
    response = await self._read_response(disable_decoding=disable_decoding)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.venv/lib64/python3.11/site-packages/redis/_parsers/resp2.py", line 90, in _read_response
    raw = await self._readline()
          ^^^^^^^^^^^^^^^^^^^^^^
  File "/app/.venv/lib64/python3.11/site-packages/redis/_parsers/base.py", line 283, in _readline
    data = await self._stream.readline()
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/asyncio/streams.py", line 566, in readline
    line = await self.readuntil(sep)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/asyncio/streams.py", line 658, in readuntil
    await self._wait_for_data('readuntil')
  File "/usr/lib64/python3.11/asyncio/streams.py", line 529, in _wait_for_data
    raise RuntimeError(
RuntimeError: readuntil() called while another coroutine is already waiting for incoming data

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