fix(dataplane): fix batch replay oom

[olamilekan000]

Change fixes a batch replay OOM risk where the handler defaulted to
a 2B(2000000000) page size and loaded all matching events into memory in one request.
It caps page size at 1000, paginates through results in
BatchReplayEventService, and applies pagination middleware to batch replay
routes.

---

Note

Medium Risk
Changes batch-replay pagination and HTTP error semantics (409 vs retryable service error), which can affect client retry behavior and how much work is enqueued per request.

Overview
Fixes a batch-replay OOM path that defaulted to a ~2B page size and loaded every matching event in one query.

BatchReplayEventService now ignores caller page size/cursors, pages internally at 1000, and fetches the next page before enqueueing the current one so a later fetch failure does not leave that page already queued (Redis replay IDs would re-fan-out on retry).

Incomplete runs that already enqueued work return 409 with success/failure counts; zero-success failures (ownership skips, fetch errors before any enqueue) stay on the retryable service-error path. Swagger documents the new 409.

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[mekilis]

This changes batch replay semantics when the caller includes list pagination params. The dashboard filter type already carries next_page_cursor, prev_page_cursor, and direction, and batchReplayEvent() sends the saved queryParams to /events/batchreplay. With this middleware, the replay starts from that cursor while /countbatchreplayevents still counts the full filter set, so the confirmation count can say N events but only the current page/window is replayed.

For a bulk replay endpoint, we should ignore caller cursors and use pagination only internally: start from the first cursor, force direction=next, cap perPage, and loop until done. Alternatively, do not attach middleware.Pagination to this route and let BatchReplayEventService build its own internal pageable.

[linear]

PDE-766

[cursor]

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[cursor]

Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

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[cursor]

Fetched page dropped on later failure

Medium Severity

When a later page fetch fails after earlier pages already enqueued work, the already-fetched current page in events is discarded without replayPage, then renderBatchReplayIncomplete returns 409 so clients avoid retrying. Up to one full BatchReplayPageSize window that was successfully loaded is silently omitted from the batch.

Additional Locations (1)

• api/handlers/event.go#L505-L514

 

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[cursor]

Current version of PR was reviewed by /review-bugbot on Aug 23, 11:32 GMT+1. It flagged 0 findings.

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