[LSF/MM/BPF TOPIC] Improving Block Layer Tracepoints for Next-Generation Backup Systems

[Song Liu]

Hi Vishnu,

On Tue, Dec 31, 2024 at 10:35 PM Vishnu ks <ksvishnu56 at gmail.com> wrote:
>
> Dear Community,
>
> I would like to propose a discussion topic regarding the enhancement
> of block layer tracepoints, which could fundamentally transform how
> backup and recovery systems operate on Linux.
>
> Current Scenario:
>
> - I'm developing a continuous data protection system using eBPF to
> monitor block request completions

This makes little sense. It is not clear how this works.

> - The system aims to achieve reliable live data replication for block devices
> Current tracepoints present challenges in capturing the complete
> lifecycle of write operations

What's the difference between this approach and existing data
replication solutions, such as md/raid?

>
> Potential Impact:
>
> - Transform Linux Backup Systems:
> - Enable true continuous data protection at block level
> - Eliminate backup windows by capturing changes in real-time
> - Reduce recovery point objectives (RPO) to near-zero
> - Allow point-in-time recovery at block granularity
>
> Current Technical Limitations:
>
> - Inconsistent visibility into write operation completion
> - Gaps between write operations and actual data flushes
> - Potential missing instrumentation points

If a tracepoint is missing or misplaced, we can fix it in a patch.

> - Challenges in ensuring data consistency across replicated volumes
>
> Proposed Improvements:
>
> - Additional tracepoints for better write operation visibility
> - Optimal placement of existing tracepoints
> - New instrumentation points for reliable block-level monitoring

Some details in these would help this topic proposal.

Thanks,
Song