test(chk): deterministic split-brain red test for CHK scale-up - #2054
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test(chk): deterministic split-brain red test for CHK scale-up#2054filimonov wants to merge 1 commit into
filimonov wants to merge 1 commit into
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Add test_020005_2: partition the sole existing keeper (pod0) from pod-to-pod
traffic, then request scale 1->3. A fire-and-forget operator brings both fresh
pods up at once; they form a 2-of-3 majority and elect a leader without pod0 --
split-brain. A safe operator stages members one at a time behind a committed-
membership barrier, so with pod0 unreachable pod2 is never created and the lone
pod1 cannot elect. Invariant: while pod0 is partitioned no leader may emerge
among the fresh nodes {1,2} -- RED on the pre-fix operator, GREEN on the fixed.
Partitioning is done at the node level via 'docker exec minikube iptables'
(no pod NET_ADMIN, no in-image iptables), so it runs on the GitHub Actions
minikube (driver: docker). A read-back 'partition is real' check from pod1
fails the test loudly rather than yielding a false green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Deterministic split-brain test for CHK Raft scale-up
Adds
test_020005_2— an e2e test that deterministically reproduces the Raft split-brain window duringClickHouseKeeperInstallationscale-up. Companion to #2041 (the fix): RED on the current release branch, GREEN with #2041 applied.Why: the existing happy-path scale-up test passes even on the pre-fix operator — the split-brain window self-heals within the assertion's retry budget, so it can't catch the bug. This test forces the window open and makes it observable.
How: partition the sole existing member (pod0) from all pod-to-pod traffic, then request scale 1→3. A fire-and-forget operator brings both fresh pods up at once; they form their own 2-of-3 majority and elect a leader without pod0 — split-brain. A safe operator stages members one at a time behind a committed-membership barrier, so with pod0 unreachable pod2 is never created and the lone pod1 can never elect. Invariant asserted: while pod0 is partitioned, no leader may emerge among the fresh nodes {1,2}.
Verified locally:
pod2 became leader among the fresh nodes while pod0 was partitioned)CI: partitioning is done at the node level via
docker exec minikube iptables(+ conntrack flush) — no podNET_ADMIN, no in-image iptables — so it runs on the GitHub Actions minikube (driver: docker). A read-back "partition is real" check fails loudly rather than yielding a false green.Draft / demonstration: this branch is based on
0.27.2and carries only the test (no operator fix), so its CI is expected to be RED on this base — that red is the point. Merging #2041 turns it green.