Skip to content

Fixed issue with db iterator closed after the callback#770

Merged
merlimat merged 1 commit intooxia-db:mainfrom
merlimat:fix-leaked-iterator
Oct 21, 2025
Merged

Fixed issue with db iterator closed after the callback#770
merlimat merged 1 commit intooxia-db:mainfrom
merlimat:fix-leaked-iterator

Conversation

@merlimat
Copy link
Copy Markdown
Collaborator

@merlimat merlimat commented Oct 21, 2025

The db iterator needs to be closed before the callback is invoked, otherwise we get the risk of the iterator getting marked as leaked, eg.:

--- FAIL: TestLeaderController_NotificationsDisabled (0.01s)
    leader_controller_test.go:1317: 
        	Error Trace:	/home/runner/work/oxia/oxia/server/leader_controller_test.go:1317
        	Error:      	Received unexpected error:
        	            	leaked iterators:
        	            	(1) attached stack trace
        	            	  -- stack trace:
        	            	  | github.com/cockroachdb/pebble/v2.(*DB).Close
        	            	  | 	/home/runner/go/pkg/mod/github.com/cockroachdb/pebble/v2@v2.1.0/db.go:1757
        	            	  | github.com/oxia-db/oxia/server/kv.(*Pebble).Close
        	            	  | 	/home/runner/work/oxia/oxia/server/kv/kv_pebble.go:378
        	            	  | github.com/oxia-db/oxia/server/kv.(*db).Close
        	            	  | 	/home/runner/work/oxia/oxia/server/kv/db.go:187
        	            	  | github.com/oxia-db/oxia/server.(*leaderController).close
        	            	  | 	/home/runner/work/oxia/oxia/server/leader_controller.go:969
        	            	  | github.com/oxia-db/oxia/server.(*leaderController).Close
        	            	  | 	/home/runner/work/oxia/oxia/server/leader_controller.go:941
        	            	  | github.com/oxia-db/oxia/server.TestLeaderController_NotificationsDisabled
        	            	  | 	/home/runner/work/oxia/oxia/server/leader_controller_test.go:1317
        	            	  | testing.tRunner
        	            	  | 	/opt/hostedtoolcache/go/1.25.3/x64/src/testing/testing.go:1934
        	            	  | runtime.goexit
        	            	  | 	/opt/hostedtoolcache/go/1.25.3/x64/src/runtime/asm_amd64.s:1693
        	            	Wraps: (2) leaked iterators:
        	            	  | L0.0:
        	            	  |   000004:[\x80\x01__oxia\xffterm#10,SET-\x80\x01__oxia\xffterm-options#11,SET]
        	            	Error types: (1) *withstack.withStack (2) *errutil.leafError
        	Test:       	TestLeaderController_NotificationsDisabled

This was happening because when we start the leader controller we start the session manager who does a list of active sessions.

When the leader controller is ready, it gets closed very quickly since the test is fast, though the iterator was still not closed in the background go-routine.

@merlimat
Fixed issue with db iterator closed after the callback
83488da 
Signed-off-by: Matteo Merli <mmerli@apache.org>
@merlimat merlimat merged commit 0b999e9 into oxia-db:main Oct 21, 2025
6 checks passed
@merlimat merlimat deleted the fix-leaked-iterator branch October 21, 2025 14:04
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@mattisonchao mattisonchao Awaiting requested review from mattisonchao mattisonchao is a code owner

@RobertIndie RobertIndie Awaiting requested review from RobertIndie RobertIndie is a code owner

Assignees

No one assigned

Labels

None yet

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

1 participant

@merlimat