myxce/.wolf/bugs/bug-1903.md

id	status	status_updated	status_note	component	severity	timestamp	last_seen	occurrences	files	tags	related	fix_commits
bug-1903	fixed	2026-10-02		apiserver	wrong-result	2026-10-01T12:21:25Z	2026-10-01T12:21:25Z	1	src/frontend/apiserver/controllers/jobs.go src/frontend/apiserver/store/query.go	apiserver query pagination code-review		efff6b65 ffb3e098

bug-1903: apiserver GetJobsInfo page_token does not advance: the next page repeats the first

Description

Observed: found by the reviewer of task 7.3 (spec job-array-one-based-index) while comparing handler behaviour with HEAD in a unit-test harness: following the page_token returned by GET /xce/v1/jobs (GetJobsInfo) returns the same page again instead of the next one. Reproduced at HEAD (before task 7.3) with a plain filter {submit_user:eq:all} and a small limit, so it is not caused by the element-selection work. Expected: passing the returned page_token yields the next page of rows, and the last page returns no token. Impact: wrong result: clients that page through job listings (xcecli jobs list with paging, REST callers) see the first page repeatedly and never reach later jobs. Found by: review (task 7.3 of spec job-array-one-based-index, 2026-10-01)

Environment

• OS: no /etc/os-release; Docker container; NixOS kernel; kernel Linux 6.18.33 x86_64
• libc: n/a (pure-Go handler path); host glibc 2.40
• Toolchain: gcc (GCC) 15.2.0, meson 1.9.1, Go from the nix dev shell
• Build: asan (build.jai); exercised through the non-cgo Go unit-test build of src/frontend/apiserver (the defect is in pure Go)
• Code: scheduler-framework @ c30e5f1d (HEAD before task 7.3) and 3457d892
• Deployment: none (controllers handler test with an in-memory store); any apiserver with more jobs than the page limit

Reproduction

1. In a controllers handler test (non-cgo, jobs_handler_test.go fixture), seed more jobs than the page limit.
2. GET /xce/v1/jobs?filter={submit_user:eq:all}&limit=2; read page_token from the response.
3. Repeat the request adding &page_token=<token>: the rows are the same as the first page.

• Frequency: deterministic (reviewer probe, 2026-10-01)
• Evidence: not kept (reviewer's temporary probe test, deleted)

Root cause

store/query.go findPageTokenIndex decoded the token with json.Unmarshal into interface{}, so the token's unique_job_id became a float64. Array element IDs set bit 62, where float64 spacing is 1024, so the token no longer named the page's last row: with no exact match findPageTokenIndex returned 0 and every page restarted at row 0 -- the reported repeat-the-first-page (the review fixture's rows are array elements); with a near match it skipped rows instead. queryControlRowsByJobID, FetchJobList and GetJobByIDs page until the token is empty, so the restart case also looped forever on arrays over 1000 elements.

Fix

efff6b65: findPageTokenIndex decodes with json.Decoder.UseNumber() and converts integers to int64 (floats stay float64), so 63-bit job IDs compare exactly. ffb3e098 adds the handler-level regression test.

Verification

• Test: TestJobHandler_QueryPagination in src/frontend/apiserver/controllers/jobs_handler_test.go (GetJobsInfo, limit=3, follows page_token): RED with efff6b65's parent store/query.go (the same three rows returned on every page until the loop guard stopped it), GREEN after; TestPaginateRowsArrayElementIDsRoundTripPageToken in store/query_test.go (2500 array elements, limit 1000): RED before efff6b65 (2452 of 2500 rows), GREEN after
• Suites: apiserver store/utils/controllers go test ok (CGO_ENABLED=0)
• Live: n/a (unit/handler level: the REST handler runs against the real store in the fixture)

References

• Related: bug-1898 (found while fixing it)