Describe the bug
A clear and concise description of what the bug is.
the feature of "offload to tiered storage" cause severe memory leak and finally shut down the broker due to OOM
To Reproduce
Steps to reproduce the behavior:
setup a simple pulsar deployment with zookeeper, bookie, and broker.
produce message to topic continuously
enable auto-offload by setting --size-threshold 10M (driver = filesystem)
and the offload works indeed but the memory consumed by broker goes up up and up
Expected behavior
A clear and concise description of what you expected to happen.
no memory leak
Screenshots
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Desktop (please complete the following information):

• OS: [e.g. iOS]
  linux

Additional context
Add any other context about the problem here.
FYI, if disable the aotu-offload, the broker works fine. Once enable "offload", broker will shut down due to OOM