Closed Bug 1040559 Opened 12 years ago Closed 10 years ago

single_head_per_branch updates branch cache, could lead to cache invalidation

Categories

(Developer Services :: Mercurial: hg.mozilla.org, defect)

Product:
Developer Services
Component:
Mercurial: hg.mozilla.org
Type:
defect
Priority:
Not set
Severity:
normal

Tracking

(Not tracked)

Status:
RESOLVED WONTFIX

People

(Reporter: gps, Unassigned)

Details

(Whiteboard: [kanban:engops:https://mozilla.kanbanize.com/ctrl_board/6/828] )

The single_head_per_branch hook almost certainly causes the branch cache to be updated because it is loading the branch map. https://hg.mozilla.org/hgcustom/hghooks/file/a7ff9c6c9e69/mozhghooks/single_head_per_branch.py#l20 This means that aborts from this hook will result in branchcache invalidation and a slow experience for whoever pushes next. This hook could likely be rewritten to not cause a branchcache update. If this is the only hook looking at branch data, it is certainly tempting, as this may mitigate some of the pain from branchcache rebuilds. Of course, fixing Mercurial is the preferred solution. Finally, I'm not 100% sure Mercurial 2.5.4 doesn't update the branch cache automatically as part of push. Someone will have to test this.
Product: Release Engineering → Developer Services
Whiteboard: [kanban:engops:https://kanbanize.com/ctrl_board/6/287]
Whiteboard: [kanban:engops:https://kanbanize.com/ctrl_board/6/287] → [kanban:engops:https://mozilla.kanbanize.com/ctrl_board/6/828] [kanban:engops:https://kanbanize.com/ctrl_board/6/287]
Whiteboard: [kanban:engops:https://mozilla.kanbanize.com/ctrl_board/6/828] [kanban:engops:https://kanbanize.com/ctrl_board/6/287] → [kanban:engops:https://mozilla.kanbanize.com/ctrl_board/6/828]
Branch cache performance issues have been fixed in modern versions of Mercurial, so this is no longer a problem.
Status: NEW → RESOLVED
Closed: 10 years ago
Resolution: --- → WONTFIX
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