with Jetstream, get "nats: timeout" when Add Stream or pull_subscribe to an existing stream

[abhishekkr]

Hi,

I'm using nats.py version 2.2.0, latest stable release.

I was using simple NATS pub/sub without JetStream. To use Jetstream, recently I started making the change..

When I tried implementing Pull Subscriber model in Python, my pull_subscribe(..) call to an existing Stream started failing with timeout.

So, I created a simple independent script as following based on NATS doc examples.. which gave similar timeout example even at an earlier stage when trying to add a new stream.

I'm running NATS server with Jetstream nats-server -js -p 4222 -DV.

Code & Error

import asyncio

import nats
from nats.errors import TimeoutError

nats_url = "nats://127.0.0.1:4222"

async def main():
    nc = await nats.connect(nats_url)
    js = nc.jetstream()
    await js.add_stream(
            name="test.x",
            subjects=["test.x.todo", "test.x.done"],
    )

    ack = await js.publish("test.x.todo", f"hello world".encode())
    print(ack)

    psub = await js.pull_subscribe("test.x.todo", "test.psub")
    msgs = await psub.fetch(1)
    for msg in msgs:
        print(msg)

    await nc.close()

if __name__ == '__main__':
    loop = asyncio.get_event_loop()
    loop.run_until_complete(main())
    loop.close()

• Error

$ python sample.py

Traceback (most recent call last):
  File "/usr/lib64/python3.11/asyncio/tasks.py", line 490, in wait_for
    return fut.result()
           ^^^^^^^^^^^^
asyncio.exceptions.CancelledError

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "$MY_APP_PATH/.venv/lib/python3.11/site-packages/nats/aio/client.py", line 999, in _request_new_style
    msg = await asyncio.wait_for(future, timeout)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib64/python3.11/asyncio/tasks.py", line 492, in wait_for
    raise exceptions.TimeoutError() from exc
TimeoutError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "$MY_APP_PATH/workers/sr-worker/sample.py", line 28, in <module>
    loop.run_until_complete(main())
  File "/usr/lib64/python3.11/asyncio/base_events.py", line 653, in run_until_complete
    return future.result()
           ^^^^^^^^^^^^^^^
  File "$MY_APP_PATH/workers/sr-worker/sample.py", line 11, in main
    await js.add_stream(
  File "$MY_APP_PATH/.venv/lib/python3.11/site-packages/nats/js/manager.py", line 89, in add_stream
    resp = await self._api_request(
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "$MY_APP_PATH/.venv/lib/python3.11/site-packages/nats/js/manager.py", line 355, in _api_request
    msg = await self._nc.request(req_subject, req, timeout=timeout)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "$MY_APP_PATH/.venv/lib/python3.11/site-packages/nats/aio/client.py", line 963, in request
    msg = await self._request_new_style(
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "$MY_APP_PATH/.venv/lib/python3.11/site-packages/nats/aio/client.py", line 1012, in _request_new_style
    raise errors.TimeoutError
nats.errors.TimeoutError: nats: timeout

[enzalito]

I've got the same problem. I tried with older versions of the lib and it didn't work either.

[mtheisen-solea]

It appears to be the latest version of NATS (2.9.15) that is causing this issue. When I reverted NATS to 2.9.14 (or 2.9.12), I was able to create a pull_subscribe and get messages from the consumer.

[ajlane]

For us this was caused by putting dots in the durable name.

[abhishekkr]

@ajlane ah thanks, good to know.. I think my subset had dots in durable name as well... I'll check a non-dot name and report back