[Bug] The current statistical method for the GROUP_GET_LATENCY metric fails to reveal its intended semantics

[RongtongJin]

Before Creating the Bug Report

• I found a bug, not just asking a question, which should be created in GitHub Discussions.

• I have searched the GitHub Issues and GitHub Discussions of this repository and believe that this is not a duplicate.

• I have confirmed that this bug belongs to the current repository, not other repositories of RocketMQ.

Runtime platform environment

All platform

RocketMQ version

RocketMQ 5.x

JDK Version

All JDK versions

Describe the Bug

The current statistical method for the GROUP_GET_LATENCY metric fails to reveal its intended semantics

The current statistics are analyzing the time to parse messages, rather than the time to retrieve messages from message store.

Steps to Reproduce

Reference code

What Did You Expect to See?

The current statistical method for the GROUP_GET_LATENCY metric can reveal its intended semantics

What Did You See Instead?

The current statistical method for the GROUP_GET_LATENCY metric can reveal its intended semantics

Additional Context

No response

[RongtongJin]

@DongyuanPan