microsoft / microsoft/CCF

Check snapshot isolation of signature transactions

Open
#6,188 0 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
C++
Stars
876
Forks
260
Avg merge
1d 11h
Merged PRs (30d)
157

Description

We may break snapshot isolation because signature transactions are special.

There is a delay between booking a version for a signature, and producing the corresponding write. What happens if a separate transaction tries to read from the signature table in that gap? Does it read an inaccurate value, or do we separate the booked-version and readable-version? Should you be allowed to read from the signature table in other transactions?

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

No files, tests, or entry points are named. Start by tracing how signature transactions book a version, produce their write, and participate in snapshot reads. Determine the expected behavior for reads from the signature table during that gap, then add coverage for the chosen isolation semantics.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
databases, distributed-systems
Issue type
Bug
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.