cloudtools/stacker

handle multiple users updating a stack at once

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#65 opened on Aug 10, 2015

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 (4 comments) (0 reactions) (0 assignees)Python (706 stars) (166 forks)batch import
enhancementhelp wantedquestion

Description

Right now there's no special logic that would stop 2 people from attempting to update stacks at the same time. In general the second attempt will see the stacks being updated, and probably do the right thing, but I can see some cases where that wouldn't happen and could leave stacks in invalid states.

So - probably worth having some way to lock the stack while you're working on it. Not sure where that would be handled.

Contributor guide

Tech stack
python
Domain
infrastructurecloudbackend
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
needs investigation
Prerequisites
PythonAWS CloudFormationbasic concurrency concepts
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
The issue proposes adding a lock to prevent concurrent stack updates. First, examine the current update process in the stacker codebase, focusing on files like `stacker/actions/base.py` or similar. Look for any existing concurrency handling. Then, consider implementing a database level lock using a table with stack names and a lock state, or using AWS DynamoDB with conditional writes. Also, review the issue comments for any suggestions. The solution should ensure that only one update per stack can run at a time, and handle timeouts or failures gracefully.