Opened 7 years ago

Last modified 4 years ago

#1788 new project-idea

MQ options

Reported by: dustin Owned by:
Priority: major Milestone: 0.9.+
Version: 0.8.3p1 Keywords:
Cc: ewong

Description (last modified by dustin)

When Buildbot adopts an MQ framework, there are a number of choices. Among them:

The first is already implemented in 'nine', but we need more.

The more difficult part of this project is to ensure that messages are only delivered after the corresponding database changes are visible.

The issue is a race condition between message passing and database replication. Imagine you have a large Buildbot installation with several replicated MySQL servers and a redundant RabbitMQ cluster. One buildbot master writes changes to a build to the database (an UPDATE operation), then sends a message describing the change. On another master, some service gets the message and queries a different MySQL server to see the build's new status. If the message arrives before the database replication occurs, then this master will see stale data. That will lead to a lot of subtle, rare bugs.

scope

This project would involve separate tasks:

  • implement one or more of the above MQ plugins (mostly just coding)
  • solve the data-ordering problem (requiring some CS theory)

relevant bugs

Change History (2)

comment:1 Changed 5 years ago by dustin

  • Cc ewong added
  • Description modified (diff)
  • Milestone changed from 1.0.+ to 0.9.+
  • Type changed from enhancement to project-idea

comment:2 Changed 4 years ago by dustin

  • Description modified (diff)
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