Pim van Pelt
6d78921edd
Three reliability fixes bundled with docs updates. Restart-neutral VPP LB sync via a startup warmup window (internal/vpp/warmup.go). Before this, a maglevd restart would immediately issue SyncLBStateAll with every backend still in StateUnknown — mapped through BackendEffectiveWeight to weight 0 — and VPP would black-hole all new flows until the checker's rise counters caught up, several seconds later. The new warmup tracker owns a process-wide state machine gated by two config knobs: vpp.lb.startup-min-delay (default 5s) is an absolute hands-off window during which neither the periodic sync loop nor the per-transition reconciler touches VPP; vpp.lb. startup-max-delay (default 30s) is the watchdog for a per-VIP release phase that runs between the two, releasing each frontend as soon as every backend it references reaches a non-Unknown state. At max-delay a final SyncLBStateAll runs for any stragglers still in Unknown. Config reload does not reset the clock. Both delays can be set to 0 to disable the warmup entirely. The reconciler's suppressed-during-warmup events log at DEBUG so operators can still see them with --log-level debug. Unit tests cover the tracker state machine, allBackendsKnown precondition, and the zero-delay escape hatch. Deterministic AS iteration in VPP LB sync. reconcileVIP and recreateVIP now issue their lb_as_add_del / lb_as_set_weight calls in numeric IP order (IPv4 before IPv6, ascending within each family) via a new sortedIPKeys helper, instead of Go map iteration order. VPP's LB plugin breaks per-bucket ties in the Maglev lookup table by insertion position in its internal AS vec, so without a stable call order two maglevd instances on the same config could push identical AS sets into VPP in different orders and produce divergent new-flow tables. Numeric sort is used in preference to lexicographic so the sync log stays human-readable: string order would place 10.0.0.10 before 10.0.0.2, and the same problem in v6. Unit tests cover empty, single, v4/v6 numeric vs lexicographic, v4-before-v6 grouping, a 1000-iteration stability loop against Go's randomised map iteration, insertion-order invariance, and the desiredAS call-site type. maglevt interval fix. runProbeLoop used to sleep the full jittered interval after every probe, so a 100ms --interval with a 30ms probe actually produced a 130ms period. The sleep now subtracts result.Duration so cadence matches the flag. Probes that overrun clamp sleep to zero and fire the next probe immediately without trying to catch up on missed cycles — a slow backend doesn't get flooded with back-to-back probes at the moment it's already struggling. Docs. config-guide now documents flush-on-down and the new startup-min-delay / startup-max-delay knobs; user-guide's maglevd section explains the restart-neutrality property, the three warmup phases, and the relevant slog lines operators should watch for during a bounce. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
11 KiB
11 KiB