Partnering:Projects:BYOB:PilotBuildQueueDetails
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Overview
This is a summary of the moving parts involved in the PHP/MySQL based build queue in use for the pilot launch of BYOB.
Contents
Repack states
The workflow status of a repack is state machine, where each state describes what actions are currently available and to which states it may transition next. A history log of these state transitions is recorded in the repack data, along with comments.
| state | description | next states |
|---|---|---|
| new | freshly created repack | edited; requested; deleted |
| edited | repack with changes | requested; deleted |
| requested | user has requested a build and review | cancelled; started; failed; pending |
| cancelled | user has cancelled a repack build and review request | edited; requested; deleted |
| started | build has started | failed; pending |
| failed | build failed for some reason | edited; requested; deleted |
| pending | build completed, review pending | cancelled; released; rejected |
| rejected | build rejected for public release | edited; requested; deleted |
| released | build approved for public release | reverted |
| reverted | public release of build taken down | edited; requested; deleted |
| deleted | repack to be deleted from system | -- |
Notes
- Repacks are locked as read-only (ie. editing via wizard is disabled) when in these states:
- requested; started; pending; approved
- Repacks get copied on edit as an unreleased version when in these states:
- released
Build queue tasks in BYOB
In reaction to certain state changes, build tasks get enqueued into a PHP/MySQL based offline work queue that gets exhausted at least every 5 minutes or so. The current build queue tasks are:
Perform build
- Enqueue triggered by repack transitioning to requested state.
- Process:
- Fire up the repack build script
- Move the built repack to private review hosting
- Result:
- If successful, transition the repack to pending state.
- If failed, transition the repack to failed state.
Release build
- Enqueue triggered by repack transitioning to released state.
- Process:
- Move a built repack from private review to public release hosting
- Result:
- In any case, repack remains in released state.
- (No failure case currently implemented.)
Delete build
- Enqueue triggered by repack transitioning to deleted state.
- Process:
- Delete a built repack from both private and public hosting
- Result:
- In any case, the repack data has been deleted from the BYOB database.
- (No failure case currently implemented.)
Build queue implementation details
The build queue consists of:
- a MySQL table listing tasks to be performed;
- a shell script that runs in a crontab or as an OS X launchd scheduled task;
- every 5 minutes or so, it sets a lock to prevent concurrent runs and exhausts the queue
- a PHP controller that processes the queue, using a model library to perform the work.
The web app uses this build queue by:
- Registering DeferredEvent callback handlers with unique IDs - these do the actual work
- Firing Events that correspond with registered DeferredEvent handlers
- Firing Events results in enqueued tasks, which the queue processor handles via calls to registered DeferredEvent callbacks.
