Have you tried increasing the memory limits for your Cloud Run service? If your memory is 8GB or more, the minimum required CPUs are 4 vCPU. You could try increasing it to see if it works; if not, the issue might be related to how Polars operates in the background. For out-of-memory errors in Cloud Run, you can review this documentation to see if it applies to your situation.

If the above doesn't work and the issue is not related to Cloud Run. You may also be affected (your polar version) by a recent announcement from the Polars team regarding the new streaming engine (#20947).

The old streaming engine is being deprecated, and the new streaming engine is coming to replace it soon™. The new streaming engine is far along, but does not yet have 100% feature parity with the old streaming engine. At the same time, the maintenance burden of maintaining both the old and new streaming engine is becoming too large. Therefore, we are deprecating the old streaming engine starting on Polars version 1.23.0 and telling people to pin their Polars versions to any version before 1.23.0.

You can also verify whether you're really affected by opening an issue on GitHub. The Polars team seems actively responding to queries and may provide workarounds.