[Bug] fatal error: OutOfMemory encountered: Java heap space

### Search before asking

- [x] I searched in the [issues](https://github.com/apache/iotdb/issues) and found nothing similar.

### Version

1.3.4

### Describe the bug and provide the minimal reproduce step

I have a standalone configuration of IoTDB on a cloud server witrh 2GB of total memory.
I am encountering fatal error due to java heap space several times per day, where datanode seems to stop working.
I have configured MEMORY_SIZE in both confignode and datanode so both values are less than 2G (e.g. 600M and 600M) but this is not working. I am attaching the error log.

[hs_err_pid67335.log](https://github.com/user-attachments/files/20003020/hs_err_pid67335.log)

Any help appreciated.

### What did you expect to see?

Sort out this annoying fatal error which is stopping the service. This did not happen before on version 1.2.x

### What did you see instead?

The service stops, unable to push any data to database

### Anything else?

_No response_

### Are you willing to submit a PR?

- [ ] I'm willing to submit a PR!

Start with the attached hs_err_pid67335.log and the MEMORY_SIZE settings for the ConfigNode and DataNode in IoTDB 1.3.4. Compare the failure with the reported 1.2.x behavior and determine why the service exhausts Java heap despite the configured limits. Done means the cause is identified and the DataNode no longer stops under the reported standalone configuration.

Written by the indexing model from the issue text.