56 lines
3.1 KiB
Markdown
56 lines
3.1 KiB
Markdown
---
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id: "bug-1914"
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status: "open"
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status_updated: "2026-10-03"
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status_note: "newly logged"
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component: "controller"
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severity: "wrong-result"
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timestamp: "2026-10-03T15:07:26Z"
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last_seen: "2026-10-03T15:07:26Z"
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occurrences: 1
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files: ["src/controller/config_repl.c", "src/controller/config_repl.h"]
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tags: ["ha", "config-push", "timeout", "load"]
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related: ["bug-1485", "bug-1913"]
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---
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# bug-1914: config push fails -110 under heavy CPU load: commit lands just after the 500 ms barrier
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## Description
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**Observed:**
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```
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Error: controller returned status -110
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```
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`xceadmin config push` to a healthy, normally elected HA primary (standbys promoted from the vote connections, own-term no-op already committed) was rejected with -ETIMEDOUT: the config marker's majority commit landed ~75 ms after the `repl_wait_majority_ack(..., CONF_PUSH_TIMEOUT_MS)` barrier (`config_repl.c` ~1658; `CONF_PUSH_TIMEOUT_MS` = 500, `config_repl.h:33`) expired. Seen only with the CPU heavily oversubscribed (40 busy loops on 32 cores).
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**Expected:** a push to a healthy primary with a reachable majority succeeds under load, or the barrier is sized/structured so normal scheduling delay cannot turn a soon-to-commit marker into a rejection. (A commit that lands after the client was told -110 also leaves the outcome ambiguous to the client: rejected per the reply, yet committed later.)
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**Impact:** spurious push failures under heavy load (fail-loud, no data loss). If the marker then commits after the -110 reply, the client believes the push failed while the cluster activated it -- a retry is idempotent per tag, but the reply is misleading. Check before changing: whether the late commit is actually applied after the -110 reply, and the async-I/O rules for the commit-wait barrier (`COMMIT_WAIT_RESERVED`, `.kiro/steering/ha-async-io.md`).
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**Found by:** test (bug-1485 investigation, 2026-10-03)
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## Environment
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- OS: no /etc/os-release; Docker container; NixOS kernel; kernel Linux 6.18.33 x86_64
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- libc: glibc 2.42-47 (interpreter /nix/store/wb6rhpznjfczwlwx23zmdrrw74bayxw4-glibc-2.42-47/lib/ld-linux-x86-64.so.2)
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- Toolchain: gcc (GCC) 15.2.0, meson 1.9.1
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- Build: asan (xce.build)
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- Code: scheduler-framework @ 4cd5fb7d-dirty
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- Deployment: local 3-node HA (xceadmin `live_ha_cluster` fixture), CPU oversubscribed with 40 busy loops on 32 cores
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## Reproduction
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1. Start 40 CPU busy loops on a 32-core host.
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2. Loop `src/xceadmin/tests/test_e2e_live_ha_push.py` (with the bug-1485 readiness wait in place).
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3. Rarely, the push fails with `controller returned status -110` on a primary whose own-term no-op had already committed; the primary log shows the marker commit ~75 ms after the 500 ms barrier expired.
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- Frequency: 1/70 HA push loops under heavy load, 0 idle (2026-10-03)
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- Evidence: not kept (scratchpad loop logs from the bug-1485 investigation)
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## Root cause
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TODO: required for fixed/partial
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## Fix
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TODO: required for fixed/partial
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## Verification
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- Test: TODO: name + file; RED before the fix, GREEN after
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- Suites: TODO: suite results and build profile
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- Live: TODO: soak/deploy run, or n/a and why
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## References
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- Related: none
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