guyinyou opened a new issue, #10038:
URL: https://github.com/apache/rocketmq/issues/10038
### Before Creating the Enhancement Request
- [x] I have confirmed that this should be classified as an enhancement
rather than a bug/feature.
### Summary
Skip the commitlog offset validation check for BLANK_MAGIC_CODE messages
(which have size 0) in the `checkCommitLogOffsetOnRecover` method.
BLANK_MAGIC_CODE is a special marker used to indicate the end of a commitlog
file when there's insufficient space, and these markers don't contain valid
message offset information that should be validated.
### Motivation
When the `checkCommitLogOffsetOnRecover` flag is enabled, the recovery
process validates commitlog offsets for all messages to ensure data integrity.
However, BLANK_MAGIC_CODE messages are special markers with size 0 that are
written at the end of commitlog files to indicate insufficient space. These
markers don't contain actual message data or valid offset information.
The current implementation attempts to validate offsets for BLANK_MAGIC_CODE
messages, which can lead to:
1. Unnecessary validation checks on non-message markers
2. Potential false warnings or errors during recovery
3. Inefficient recovery process
By skipping offset validation for BLANK_MAGIC_CODE messages, we improve the
recovery process accuracy and efficiency, ensuring that only actual messages
with valid data are subject to offset validation.
### Describe the Solution You'd Like
Add a size check condition before performing the commitlog offset validation
in the `checkCommitLogOffsetOnRecover` method. Specifically, modify the
condition from:
```java
if (checkCommitLogOffsetOnRecover) {
```
to:
```java
if (size > 0 && checkCommitLogOffsetOnRecover) {
```
This ensures that offset validation is only performed on actual messages
(size > 0) and skips BLANK_MAGIC_CODE markers (size = 0) that are returned by
`checkMessageAndReturnSize` when encountering the end-of-file marker.
The implementation is straightforward:
- Check if the message size is greater than 0 before performing offset
validation
- This naturally excludes BLANK_MAGIC_CODE messages which always have size 0
- No changes needed to the BLANK_MAGIC_CODE detection logic itself
### Describe Alternatives You've Considered
1. **Explicitly check for BLANK_MAGIC_CODE**: Instead of checking size > 0,
we could explicitly check the magic code. However, this would require accessing
the magic code from the DispatchRequest or re-reading the buffer, which is less
efficient and more complex than simply checking the size.
2. **Modify DispatchRequest to include a flag**: We could add a flag to
DispatchRequest to indicate whether it's a BLANK_MAGIC_CODE marker. However,
this would require changes to the DispatchRequest class and all its usages,
which is more invasive than necessary.
3. **Skip validation based on success flag only**: We considered relying
solely on the `isSuccess()` flag, but this doesn't distinguish between
BLANK_MAGIC_CODE markers (which return success with size 0) and actual messages
(which also return success with size > 0).
The chosen solution (checking `size > 0`) is the most efficient and least
invasive approach, as it leverages the existing size information that's already
available and naturally distinguishes between actual messages and
BLANK_MAGIC_CODE markers.
### Additional Context
_No response_
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