vip-upgrade netns: the epoch read is single-shot #133

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opened 2026-10-09 14:59:18 -03:00 by marcos-mendez · 0 comments

marcos-mendez commented

2026-10-09 14:59:18 -03:00

(Migrated from github.com)

In tests/test_vip_upgrade_netns.py::TestUpgradesKeepTheVip::test_b_etcd_restarted_on_each_member_in_turn, epoch() asks C for the VIP claim with one agent_send (tests/vip_upgrade_netns.py). The "epoch" handler does one linearizable etcd read over the lossy link (250 ms, 2% loss); when the read outlasts its 2 s timeout it answers {"error": ...} with no "epoch" key, and the driver records epoch_before = None. The assertion assertIsNotNone(one["epoch_before"]) then fails even though the VIP never moved (holders_seen "A" throughout).

Evidence: 2026-10-09, run 37966794940 job 113943040489 (PR #132, product code = main). The driver already carries the same fix pattern for upgrade-check (healthy_when_asked, keel#94) and the vip scenario retries etcd-timeout phrases; the epoch read wants the same treatment: retry while the answer holds no epoch, bounded. Refs keel#94.

In tests/test_vip_upgrade_netns.py::TestUpgradesKeepTheVip::test_b_etcd_restarted_on_each_member_in_turn, `epoch()` asks C for the VIP claim with one agent_send (tests/vip_upgrade_netns.py). The "epoch" handler does one linearizable etcd read over the lossy link (250 ms, 2% loss); when the read outlasts its 2 s timeout it answers {"error": ...} with no "epoch" key, and the driver records epoch_before = None. The assertion assertIsNotNone(one["epoch_before"]) then fails even though the VIP never moved (holders_seen [[\"A\"]] throughout). Evidence: 2026-10-09, run 37966794940 job 113943040489 (PR #132, product code = main). The driver already carries the same fix pattern for upgrade-check (healthy_when_asked, keel#94) and the vip scenario retries etcd-timeout phrases; the epoch read wants the same treatment: retry while the answer holds no epoch, bounded. Refs keel#94.