haskell-distributed / haskell-distributed/distributed-process

Fix testBreakConnection and undo workaround

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#250 4 comments 0 reactions 0 assignees View on GitHub

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Dominant language
Haskell
Stars
751
Forks
99
Avg merge
45m
Merged PRs (30d)
2

Description

The bug:

A process PA in NA monitors a process PB in NB
NA and NB are disconnected
PA tries to send a message to another process PB1 in NB
A monitor notification about PB1 death arrives to PA
No monitor notification about PB arrives to PA.

This is observed only in tests so far (MonitorNode, MonitorLiveNode, MonitorChannel from CH). These tests break connections with testBreakConnection, which doesn't deliver EventConnectionLost. If the transport delivered EventConnectionLost, then d-p would notify the death of all processes, I hope.

Instead, d-p has a patch that workarounds the problem: haskell-distributed#246

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

Start by reading testBreakConnection and the MonitorNode, MonitorLiveNode, and MonitorChannel tests to understand how the connection is broken and which notifications are expected. Then review the workaround described in haskell-distributed#246 and trace the transport handling of EventConnectionLost; done means the tests receive the expected death notifications without that workaround.

Written by the indexing model from the issue text.

Assessment

Tech stack
haskell
Domain
distributed-systems, testing-qa
Issue type
Bug
Difficulty
5/5
Estimated time
Over a week
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
25/100

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