OAuth Azure Event Hub for Kafka failing starting with 2.6.0

[yann-combarnous]

Description

Copying report from Confluent Kafka report library, as error is reported by librdkafka (confluentinc/confluent-kafka-python#1845), and multiple people are affected:

I'm using Azure Event Hubs with the confluent-kafka client with OAuth-Authentication. While the following snippet worked with confluent-kafka 2.4.0 and 2.5.0, it stopped working with 2.6.0 (librdkafka 2.6.0) with this error:

%6|1730980586.653|FAIL|rdkafka#consumer-1| [thrd:sasl_ssl://xxx.servicebus.windows.net:9093/bootstrap]: sasl_ssl://xxx.servicebus.windows.net:9093/0: Disconnected (after 3891ms in state UP)

Maybe I'm missing something. I would appreciate any hints!

How to reproduce

from functools import partial

from azure.identity import DefaultAzureCredential
from confluent_kafka import Consumer


def get_token(namespace: str, config: str) -> tuple[str, float]:
    token = DefaultAzureCredential().get_token(f"https://{namespace}/.default")
    return token.token, token.expires_on


def main():
    namespace = "xxx.servicebus.windows.net"
    topic = "test-hub"

    conf = {
        "bootstrap.servers": f"{namespace}:9093",
        "group.id": "quix-consumer",
        "security.protocol": "sasl_ssl",
        "sasl.mechanisms": "OAUTHBEARER",
        "oauth_cb": partial(get_token, namespace),
        "auto.offset.reset": "earliest",
    }

    consumer = Consumer(conf)
    consumer.subscribe([topic])

    while True:
        try:
            msg = consumer.poll(1.0)
            if msg is None:
                continue

            print(msg.value())

        except KeyboardInterrupt:
            break

    consumer.close()

if __name__ == "__main__":
    main()

Checklist

Please provide the following information:

• confluent-kafka-python and librdkafka version (confluent_kafka.version() and confluent_kafka.libversion()): 2.6.0
• Apache Kafka broker version: Azure Event Hubs
• Client configuration: {...}
• Operating system: Microsoft Windows 11 Business - 10.0.26100 Build 26100
• Provide client logs (with 'debug': '..' as necessary)
• nh Provide broker log excerpts
• Critical issue

Full debug log:

%7|1730998906.887|FAIL|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: Closing connection due to nodename change (after 1ms in state AUTH_HANDSHAKE) (_TRANSPORT)
%7|1730998906.887|TERM|rdkafka#consumer-1| [thrd:main]: Setting state to TERMINATED and signalling
%7|1730998906.887|STATE|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: Broker changed state AUTH_HANDSHAKE -> DOWN
%7|1730998906.887|TERM|rdkafka#consumer-1| [thrd:app]: Ended waiting for termination of telemetry.
%7|1730998906.889|TERMINATE|rdkafka#consumer-1| [thrd:app]: Interrupting timers
%7|1730998906.887|BROADCAST|rdkafka#consumer-1| [thrd:GroupCoordinator]: Broadcasting state change
%7|1730998906.889|BUFQ|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: Purging bufq with 1 buffers
%7|1730998906.889|TERMINATE|rdkafka#consumer-1| [thrd:app]: Sending TERMINATE to internal main thread
%7|1730998906.889|FAIL|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: SASL OAUTHBEARER mechanism handshake failed: Local: Broker transport failure: broker's supported mechanisms: (n/a) (after 0ms in state DOWN) (_AUTHENTICATION)
%7|1730998906.889|TERMINATE|rdkafka#consumer-1| [thrd:app]: Joining internal main thread
%7|1730998906.889|TERMINATE|rdkafka#consumer-1| [thrd:main]: Internal main thread terminating
%3|1730998906.889|FAIL|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: SASL OAUTHBEARER mechanism handshake failed: Local: Broker transport failure: broker's supported mechanisms: (n/a) (after 0ms in state DOWN)  
%7|1730998906.890|BUFQ|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: Purging bufq with 0 buffers
%7|1730998906.890|BUFQ|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: Purging bufq with 0 buffers
%7|1730998906.890|DESTROY|rdkafka#consumer-1| [thrd:main]: Destroy internal
%7|1730998906.890|BUFQ|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: Updating 0 buffers on connection reset
%7|1730998906.890|BROADCAST|rdkafka#consumer-1| [thrd:main]: Broadcasting state change
%7|1730998906.890|BRKTERM|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: terminating: broker still has 4 refcnt(s), 0 buffer(s), 0 partition(s)
%7|1730998906.890|DESTROY|rdkafka#consumer-1| [thrd:main]: Removing all topics
%7|1730998906.890|BUFQ|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: Purging bufq with 0 buffers
%7|1730998906.891|DESTROY|rdkafka#consumer-1| [thrd:main]: Sending TERMINATE to sasl_ssl://xxx.servicebus.windows.net:9093/0
%7|1730998906.891|BUFQ|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: Updating 0 buffers on connection reset
%7|1730998906.891|DESTROY|rdkafka#consumer-1| [thrd:main]: Sending TERMINATE to GroupCoordinator
%7|1730998906.891|TERM|rdkafka#consumer-1| [thrd:sasl_ssl://xxx.servicebus.windows.net:9093/bootstrap]: sasl_ssl://xxx.servicebus.windows.net:9093/0: Received TERMINATE op in state UP: 2 refcnts, 0 toppar(s), 0 active toppar(s), 0 outbufs, 0 waitresps, 0 retrybufs
%7|1730998906.892|BRKTERM|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: terminating: broker still has 3 refcnt(s), 0 buffer(s), 0 partition(s)
%7|1730998906.892|TERMINATE|rdkafka#consumer-1| [thrd:main]: Purging reply queue
%7|1730998906.892|TERMINATE|rdkafka#consumer-1| [thrd:GroupCoordinator]: GroupCoordinator: Handle is terminating in state DOWN: 2 refcnts (000001834E99DE58), 0 toppar(s), 0 active toppar(s), 0 outbufs, 0 waitresps, 0 retrybufs: failed 0 request(s) in retry+outbuf
%7|1730998906.892|FAIL|rdkafka#consumer-1| [thrd:sasl_ssl://xxx.servicebus.windows.net:9093/bootstrap]: sasl_ssl://xxx.servicebus.windows.net:9093/0: Client is terminating (after 143ms in state UP) (_DESTROY)  
%7|1730998906.892|TERMINATE|rdkafka#consumer-1| [thrd:main]: Decommissioning internal broker