Hacktoberfest 2026: as issues que os mantenedores marcaram para outubro, abertas e boas para iniciantes. Ver issues do Hacktoberfest

A late acknowledgement can overwrite the retry attempt that replaced it

Fechada
  • Algo errado?
#80 0 comentários 0 reações 0 responsáveis Ver no GitHub

Mantenedores costumam responder em até 1 dia

Ninguém assumiu esta issue ainda.

Avaliação

Dificuldade
4/5
Tempo estimado
3-5 dias
Facilidade para iniciantes
48/100
Tipo de issue
Bug
Clareza
Razoavelmente clara
Status de atividade
Ativa
Stack de tecnologia
lua, redis
Domínio
backend, distributed-systems

Direção de pesquisa

Start with threadmill/backends/lua/acknowledge.lua and read the README section describing retries that outlive their leases. Trace how a late acknowledgement interacts with the reaper's requeued attempt, then define done as preventing the stale result from replacing the current attempt or removing its running state; the issue leaves the fencing approach open.

Escrita pelo modelo de indexação a partir do texto da issue.

Descrição

Found while reviewing PR #69 with the SuperJoe crew (pre-existing, untouched by that patch), filed as out-of-scope there.

acknowledge.lua fences only on running-set membership: it ZREMs the id and proceeds only when the id was there. A worker whose lease expired but which is still running can acknowledge after the reaper requeued the task for a retry: the reaper's claim re-armed the running entry, so the late ack's ZREM succeeds. It then writes the stale result, deletes the task hash, and removes the new attempt's running entry — while the deferred entry the retry created survives and runs the task again.

The README already documents that a retry may execute concurrently with a task that outlived its lease, so duplicate execution is expected. What is not expected is the late ack publishing a result for the wrong attempt and destroying the retry's state.

Options:

  • fence the ack on the attempt it was leased for, e.g. a per-attempt token written beside the lease and compared by the script, or
  • let an ack lose to a renewed claim.

Reference: threadmill/backends/lua/acknowledge.lua.

Linguagem predominante
Python
Estrelas
21
Forks
2
Merge médio
12h 38min
PRs com merge (30d)
27

Preparar o ambiente

Primeiros passos

  1. Leia a issue inteira e depois o guia de contribuição do projeto.
  2. Comente na issue dizendo que vai assumir — evita que duas pessoas façam o mesmo trabalho.
  3. Faça um fork do repositório e trabalhe em uma branch.
  4. Abra um pull request que referencie o número da issue.

Issues semelhantes

Mais issues de Python

Receba novas issues na sua caixa de entrada

Um resumo curto de issues do GitHub para quem está começando.