MQRC_TRUNCATED_MSG_FAILED when pulling IBM ACE statistics from IBM MQ

Hello, When using the IBM ACE integration, we are seeing intermittent `MQRC_TRUNCATED_MSG_FAILED` errors in the Datadog Agent logs. Based on the [IBM MQ documentation](https://www.ibm.com/docs/en/ibm-mq/9.2.x?topic=SSFKSJ_9.2.0/com.ibm.mq.ref.doc/q041460_.htm), this error occurs when the client specifies a buffer that is too small for a message being received. **Full exception in Datadog agent logs:** ``` 2026-02-18 13:44:16 GMT | CORE | ERROR | (pkg/collector/python/datadog_agent.go:144 in LogMessage) | ibm_ace:e879804a74649c26 | (subscription.py:86) | Subscription error for topic string: $SYS/Broker/+/Statistics/JSON/SnapShot/#/applications/# Traceback (most recent call last): File "/opt/datadog-agent/embedded/lib/python3.13/site-packages/datadog_checks/ibm_ace/subscription.py", line 69, in get_latest_messages payload = self.sub.get(None, pymqi.md(), self._get_options()) File "/opt/datadog-agent/embedded/lib/python3.13/site-packages/pymqi/__init__.py", line 2517, in get return self.sub_queue.get(max_length, *opts) ~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^ File "/opt/datadog-agent/embedded/lib/python3.13/site-packages/pymqi/__init__.py", line 2159, in get raise MQMIError(rv[-2], rv[-1]) pymqi.MQMIError: MQI Error. Comp: 1, Reason 2080: WARNING: MQRC_TRUNCATED_MSG_FAILED ``` **Impact** Metrics datapoints from the failed messages will not be sent to Datadog. **Steps to reproduce:** - Configure the agent's IBM ACE integration to monitor an IBM ACE server as described [here](https://docs.datadoghq.com/integrations/ibm-ace/). - Load test with a large amount of integration servers/message queues. With sufficient volume, statistics messages will occasionally be too large and the above error will appear in the logs. **Investigation:** - Looking at the integration code [here](https://github.com/DataDog/integrations-core/blob/579826fd707335d657fef6f2d003910542d6dd8e/ibm_ace/datadog_checks/ibm_ace/subscription.py#L69), there is currently no maximum buffer size being specified in the integration (first parameter in the `get()` function call, currently set to `None`.) - Looking at the behavior in the `pymqi` library [here](https://github.com/Dynatrace-Reinhard-Pilz/py3mqi/blob/f77c13ec43b09921c0be9f3ba3f975be76f4d6a9/code/pymqi/__init__.py#L1772C1-L1772C30), if a maximum buffer length is not specified, it falls back to 4096 bytes. **Suggested solutions:** 1. Use the `inquire()` method ([here](https://github.com/Dynatrace-Reinhard-Pilz/py3mqi/blob/f77c13ec43b09921c0be9f3ba3f975be76f4d6a9/code/pymqi/__init__.py#L1855)) to query for the maximum message length allowed by the queue, and set the maximum buffer size dynamically. 2. Add a `try`/`except` case for the integration to re-request with a larger buffer size if this exception is thrown. 3. Make the buffer size configurable so operators can set it to match the maximum message length configured on the queue.