5 Commits

Author SHA1 Message Date
Pim van Pelt
701674399a Release v1.0.0 under Apache-2.0 license 2026-04-15 18:14:28 +02:00
Pim van Pelt
6d78921edd Restart-neutral VPP LB sync; deterministic AS ordering; maglevt cadence; v0.9.5
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>
2026-04-15 12:53:42 +02:00
Pim van Pelt
4347bb9b05 Bug fixes, config validation, SPA tightening, set-weight UI
This session covers three distinct arcs: correctness bug fixes in the
VPP sync path and frontend reducers, new config validation, and a
large polish pass on the web frontend (tighter layout, backend kebab
dialogs, live grouped-table, live config-reload re-sync).

 - encap for a VIP is now derived from the backend address family,
   not the VIP's. A v6 VIP with v4 backends is programmed as IP6_GRE4
   (not the buggy IP6_GRE6), matching the VPP LB plugin's
   requirement that encap reflects the tunnel inner family. desiredVIP
   gained an Encap field populated in desiredFromFrontend.
 - ActivePoolIndex now requires at least one backend in a pool to be
   BOTH in StateUp AND pb.Weight>0 before the pool counts as active.
   Previously a primary pool with every backend manually zeroed would
   still win over a fallback with weight=100, so fallback traffic
   never materialized. New TestActivePoolIndexWeightedFailover table
   pins the rule in five subcases.
 - SyncLBStateVIP gained a flushAddress parameter threaded through
   reconcileVIP; it forces flush=true on the setASWeight call for a
   specific backend regardless of the usual 0→N heuristic. Wires up
   the explicit [flush] knob the CLI exposes.

 - convertFrontend already enforced that backends within one frontend
   share a family. New cross-frontend pass validateVIPFamilyConsistency
   rejects configs where two frontends share a VIP address but carry
   backends in different families — VPP's LB plugin requires every
   VIP on a prefix to have the same encap type, so such a config
   would fail at lb_add_del_vip_v2 time with VNET_API_ERROR_INVALID
   _ARGUMENT (-73). Catching it at config load turns a silent
   runtime failure into a clear startup error.
 - Two new TestValidationErrors cases pin the behavior: mismatched
   families reject, same-family frontends on one VIP address allowed.

 - Proto adds `bool flush = 5` to SetWeightRequest. The RPC now
   drives a VIP sync immediately after mutating config (fixing the
   latent "weight change only takes effect at the next 30s periodic
   reconcile" gap), passing flushAddress = backend IP when req.Flush
   is true.
 - maglevc grows an optional [flush] token: `set frontend F pool P
   backend B weight N [flush]`. Implementation uses two Run closures
   (runSetFrontendPoolBackendWeight and -Flush) because the tree
   walker only puts slot tokens in args — literal keywords like
   `flush` advance the node but don't appear in the arg list.
 - docs/user-guide.md updated with the [flush] optional and a
   three-paragraph explainer of the graceful-drain vs. flush
   semantics at the VPP level.

 - checker.ListFrontends now sorts alphabetically to match the
   existing sort in ListBackends / ListHealthChecks — RPC responses
   no longer shuffle VIPs per call. cmd/frontend/client.go also
   sorts defensively in refreshAll so an old maglevd build renders
   alphabetically too.
 - backendFromProto was returning out.Transitions[n-1] as the
   LastTransition, but maglevd stores (and the proto carries)
   transitions newest-first, so [n-1] was actually the oldest.
   Reverse on read, which normalizes the client's Transitions slice
   to oldest-first and makes [n-1] genuinely the newest. LastTransition
   now points at the actual latest transition record.
 - applyBackendTransition (Go and TS) derives Enabled = state!="disabled"
   so the two fields stay in lockstep — closed a drift window where
   a recently re-enabled backend still rendered with a stuck
   [disabled] tag. The tag was later removed entirely since state
   and enabled carry the same information.

 - Layout tightened substantially: "FRONTENDS" panel header removed,
   zippy-summary and zippy-body paddings cut, backend-table row
   padding dropped to 2px, per-pool <h3> removed. Pools now live in
   a single consolidated table per frontend with a dedicated "pool"
   column that shows the pool name only on the first row of each
   group — classic grouped-table layout, maximally dense.
 - Description moved inline into the Zippy summary as muted italic
   text, freeing a vertical line per frontend card.
 - formatVIPAddress() helper renders IPv6 VIPs as [addr]:port and
   IPv4 as addr:port, matching RFC 3986 authority syntax.
 - Pools with effective_weight=0 on every backend (standby
   fallbacks, fully-drained primaries) render at opacity 0.35 on
   their non-actions cells; the kebab column stays at full contrast
   because its menu is still fully functional on standby backends.
 - Config-reload propagation: a maglevd config-reload-done log
   event triggers triggerConfigResync() on the frontend side —
   refreshAll() runs off the event-dispatch goroutine, then a
   BrowserEvent{Type:"resync"} is published through the broker.
   writeEvent emits type="resync" as a named SSE frame so the
   SPA's existing addEventListener("resync") handler picks it up
   and calls fetchAllState → replaceAll.
 - recomputeEffectiveWeights in stores/state.ts mirrors the
   server-side health.EffectiveWeights logic so the SPA keeps
   pool.effective_weight correct the moment a backend transitions,
   without waiting for the 30s refresh. Fixed a nasty bug where
   applyBackendEffectiveWeight wrote VIP-scoped vpp-lb-sync-as-*
   event weights into every frontend sharing the backend,
   corrupting frontends with different per-pool configured weights.
   The old log-event reducer was removed; applyConfiguredWeight is
   the narrower replacement used by the kebab set-weight flow.
 - applyBackendTransition calls recomputeEffectiveWeights after
   state updates so pool-failover transitions (primary ⇌ fallback)
   reflect instantly in the UI.

 - Confirmation dialogs via a new Modal primitive
   (Portal-mounted to document.body, escape/click-outside close,
   click-outside debounced on mousedown so mid-row-text-selection
   drags don't dismiss).
 - pause/resume/enable/disable each show a Modal with a consequence
   paragraph explaining what hits live traffic ("will keep existing
   flows", "will flush VPP's flow table", etc.). The disable commit
   button is styled btn-danger red.
 - set-weight action shows a Modal with a range slider (0-100,
   seeded from the current configured weight, accent-colored live
   numeric readout via <output>) plus a flush checkbox and a live-
   swapping note/warn paragraph describing what will happen. On
   commit, the SPA also updates its local store via
   applyConfiguredWeight so the operator sees the new weight
   immediately without waiting for the next refresh.

 - ProbeHeartbeat is now state-aware: ▶ (play) at rest for up/
   down/unknown backends, ⏸ (pause) for paused, ⏹ (stop) for
   disabled/removed, ❤️ (heart) during an in-flight probe.
 - Drop the probe-done event listener — fast probes (<10ms)
   could fire probe-done in the same render tick as probe-start
   and the heart would never visibly paint. Each probe-start now
   runs a fixed 400ms scale-pop animation on a timer; subsequent
   probe-start events reset the timer, so fast cadences produce a
   continuous heart pulse.
 - Fixed wrapper box (16x14 px, overflow hidden) so the row
   doesn't jiggle when the glyph swaps between the narrow ▶/⏸/⏹
   text glyphs and the wider ❤️ emoji.

 - Brand wordmark changed from "maglev" to "vpp-maglev" and wrapped
   in an <a> linking to https://git.ipng.ch/ipng/vpp-maglev. Logo
   link changed to https://ipng.ch/. Both open in a new tab with
   rel="noopener".
 - .gitignore fix: `frontend`, `maglevc`, `maglevd` were matching
   ANY file or directory with those names anywhere in the tree,
   silently ignoring cmd/frontend and friends. Anchored with
   leading slashes so only repo-root build artifacts match.
2026-04-12 23:06:42 +02:00
Pim van Pelt
fb62532fd5 VPP LB counters, src-ip-sticky, and frontend state aggregation
New feature: per-VIP / per-backend runtime counters
  * New GetVPPLBCounters RPC serving an in-process snapshot refreshed
    by a 5s scrape loop (internal/vpp/lbstats.go). Each cycle pulls
    the LB plugin's four SimpleCounters (next, first, untracked,
    no-server) plus the FIB /net/route/to CombinedCounter for every
    VIP and every backend host prefix via a single DumpStats call.
  * FIB stats-index discovery via ip_route_lookup (internal/vpp/
    fibstats.go); per-worker reduction happens in the collector.
  * Prometheus collector exports vip_packets_total (kind label),
    vip_route_{packets,bytes}_total, and backend_route_{packets,
    bytes}_total. Metrics source interface extended with VIPStats /
    BackendRouteStats; vpp.Client publishes snapshots via
    atomic.Pointer and clears them on disconnect.
  * New 'show vpp lb counters' CLI command. The 'show vpp lbstate'
    and 'sync vpp lbstate' commands are restructured under 'show
    vpp lb {state,counters}' / 'sync vpp lb state' to make room
    for the new verb.

New feature: src-ip-sticky frontends
  * New frontend YAML key 'src-ip-sticky' (bool). Plumbed through
    config.Frontend, desiredVIP, and the lb_add_del_vip_v2 call.
  * Reflected in gRPC FrontendInfo.src_ip_sticky and VPPLBVIP.
    src_ip_sticky, and shown in 'show vpp lb state' output.
  * Scraped back from VPP by parsing 'show lb vips verbose' through
    cli_inband — lb_vip_details does not expose the flag. The same
    scrape also recovers the LB pool index for each VIP, which the
    stats-segment counters are keyed on. This is a documented
    temporary workaround until VPP ships an lb_vip_v2_dump.
  * src_ip_sticky cannot be mutated on a live VIP, so a flipped flag
    triggers a tear-down-and-recreate in reconcileVIP (ASes deleted
    with flush, VIP deleted, then re-added). Flip is logged.

New feature: frontend state aggregation and events
  * New health.FrontendState (unknown/up/down) and FrontendTransition
    types. A frontend is 'up' iff at least one backend has a nonzero
    effective weight, 'unknown' iff no backend has real state yet,
    and 'down' otherwise.
  * Checker tracks per-frontend aggregate state, recomputing after
    each backend transition and emitting a frontend-transition Event
    on change. Reload drops entries for removed frontends.
  * checker.Event gains an optional FrontendTransition pointer;
    backend- vs. frontend-transition events are demultiplexed on
    that field.
  * WatchEvents now sends an initial snapshot of frontend state on
    connect (mirroring the existing backend snapshot), subscribes
    once to the checker stream, and fans out to backend/frontend
    handlers based on the client's filter flags. The proto
    FrontendEvent message grows name + transition fields.
  * New Checker.FrontendState accessor.

Refactor: pure health helpers
  * Moved the priority-failover selector and the (pool idx, active
    pool, state, cfg weight) → (vpp weight, flush) mapping out of
    internal/vpp/lbsync.go into a new internal/health/weights.go so
    the checker can reuse them for frontend-state computation
    without importing internal/vpp.
  * New functions: health.ActivePoolIndex, BackendEffectiveWeight,
    EffectiveWeights, ComputeFrontendState. lbsync.go now calls
    these directly; vpp.EffectiveWeights is a thin wrapper over
    health.EffectiveWeights retained for the gRPC observability
    path. Fully unit-tested in internal/health/weights_test.go.

maglevc polish
  * --color default is now mode-aware: on in the interactive shell,
    off in one-shot mode so piped output is script-safe. Explicit
    --color=true/false still overrides.
  * New stripHostMask helper drops /32 and /128 from VIP display;
    non-host prefixes pass through unchanged.
  * Counter table column order fixed (first before next) and
    packets/bytes columns renamed to fib-packets/fib-bytes to
    clarify they come from the FIB, not the LB plugin.

Docs
  * config-guide: document src-ip-sticky, including the VIP
    recreate-on-change caveat.
  * user-guide, maglevc.1, maglevd.8: updated command tree, new
    counters command, color defaults, and the src-ip-sticky field.
2026-04-12 16:07:39 +02:00
Pim van Pelt
0049c2ae73 VPP reconciler: event-driven sync, pool failover, bug fixes
This commit wires the checker's state machine through to the VPP dataplane:
every backend state transition flows through a single code path that
recomputes the effective per-backend weight (with pool failover) and pushes
the result to VPP. Along the way several latent bugs in the state machine
and the sync path were fixed.

internal/vpp/reconciler.go (new)
- New Reconciler type subscribes to checker.Checker events and, on every
  transition, calls Client.SyncLBStateVIP for the affected frontend. This
  is the ONLY place in the codebase where backend state changes cause VPP
  calls — the "single path" discipline requested during design.
- Defines an EventSource interface (checker.Checker satisfies it) so the
  dependency direction stays vpp → checker; the checker never imports vpp.

internal/vpp/client.go
- Renamed ConfigSource → StateSource. The interface now has two methods:
  Config() and BackendState(name) — the reconciler and the desired-state
  builder both need live health state to compute effective weights.
- SetConfigSource → SetStateSource; internal cfgSrc field → stateSrc.
- New getStateSource() helper for internal locked access.
- lbSyncLoop still uses the state source for its periodic drift
  reconciliation; it's fully idempotent and runs the same code path as
  event-driven syncs.

internal/vpp/lbsync.go
- desiredAS grows a Flush bool so the mapping function can signal "on
  transition to weight 0, flush existing flow-table entries".
- asFromBackend is now the single source of truth for the state →
  (weight, flush) rule. Documented with a full truth table. Takes an
  activePool parameter so it can distinguish "up in active pool" from
  "up but standby".
- activePoolIndex(fe, states) implements priority failover: returns the
  index of the first pool containing any StateUp backend. pool[0] wins
  when at least one member is up; pool[1] takes over when pool[0] is
  empty; and so on. Defaults to 0 (unobservable, since all backends map
  to weight 0 when nothing is up).
- desiredFromFrontend snapshots backend states once, computes activePool,
  then walks every backend through asFromBackend. No more filtering on
  b.Enabled — disabled backends stay in the desired set so they keep
  their AS entry in VPP with weight=0. The previous filter caused delAS
  on disable, which destroyed the entry and broke enable afterwards.
- EffectiveWeights(fe, src) exported helper that returns the per-pool
  per-backend weight map for one frontend. Used by the gRPC GetFrontend
  handler and robot tests to observe failover without touching VPP.
- reconcileVIP computes flush at the weight-change call site:
    flush = desired.Flush && cur.Weight > 0 && desired.Weight == 0
  This ensures only the *transition* to disabled flushes sessions —
  steady-state syncs with already-zero weight skip the call entirely.
- setASWeight now plumbs IsFlush into lb_as_set_weight.

internal/vpp/lbsync_test.go (new)
- TestAsFromBackend: 15 cases locking down the truth table, including
  failover scenarios (up in standby pool, up promoted in pool[1]).
- TestActivePoolIndex: 8 cases covering pool[0]-has-up, pool[0]-all-down,
  all-disabled, all-paused, all-unknown, nothing-up-anywhere, and
  three-tier failover.
- TestDesiredFromFrontendFailover: 5 end-to-end scenarios wiring a fake
  StateSource through desiredFromFrontend and asserting the final
  per-IP weight map. Exercises the complete pipeline without VPP.

internal/checker/checker.go
- Added BackendState(name) (health.State, bool) — one-line method that
  satisfies vpp.StateSource. The checker is otherwise unchanged.
- EnableBackend rewritten to reuse the existing worker (parallel to
  ResumeBackend). The old code called startWorker which constructed a
  brand-new Backend via health.New, throwing away the transition
  history; the resulting 'backend-transition' log showed the bogus
  from=unknown,to=unknown. Now uses w.backend.Enable() to record a
  proper disabled→unknown transition and launches a fresh goroutine.
- Static (no-healthcheck) backends now fire their synthetic 'always up'
  pass on the first iteration of runProbe instead of sleeping 30s
  first. Previously static backends sat in StateUnknown for 30s after
  startup — useless for deterministic testing and surprising for
  operators. The fix is a simple first-iteration flag.

internal/health/state.go
- New Enable(maxHistory) method parallel to Disable. Transitions the
  backend from whatever state it's in (typically StateDisabled) to
  StateUnknown, resets the health counter to rise-1 so the expedited
  resolution kicks in on the first probe result, and emits a transition
  with code 'enabled'.

proto/maglev.proto
- PoolBackendInfo gains effective_weight: the state-aware weight that
  would be programmed into VPP (distinct from the configured weight in
  the YAML). Exposed via GetFrontend.

internal/grpcapi/server.go
- frontendToProto takes a vpp.StateSource, computes effective weights
  via vpp.EffectiveWeights, and populates PoolBackendInfo.EffectiveWeight.
- GetFrontend and SetFrontendPoolBackendWeight updated to pass the
  checker in.

cmd/maglevc/commands.go
- 'show frontends <name>' now renders every pool backend row as
    <name>  weight <cfg>  effective <eff>  [disabled]?
  so both values are always visible. The VPP-style key/value format
  avoids the ANSI-alignment pitfall we hit earlier and makes the output
  regex-parseable for robot tests.

cmd/maglevd/main.go
- Construct and start the Reconciler alongside the VPP client. Two
  extra lines, no other changes to startup.

tests/01-maglevd/maglevd-lab/maglev.yaml
- Two new static backends (static-primary, static-fallback) and a new
  failover-vip frontend with one backend per pool. No healthcheck, so
  the state machine resolves them to 'up' immediately via the synthetic
  pass. Used by the failover robot tests.

tests/01-maglevd/01-healthcheck.robot
- Three new test cases exercising pool failover end-to-end:
  1. primary up, secondary standby (initial state)
  2. disable primary → fallback takes over (effective weight flips)
  3. enable primary → fallback steps back
  All run without VPP: they scrape 'maglevc show frontends <name>' and
  regex-match the effective weight in the output. Deterministic and
  fast (~2s total) because the static backends don't probe.
- Two helper keywords: Static Backend Should Be Up and
  Effective Weight Should Be.

Net result: 16/16 robot tests pass. Backend state transitions now
flow through a single documented path (checker event → reconciler →
SyncLBStateVIP → desiredFromFrontend → asFromBackend → reconcileVIP →
setASWeight), and the pool failover / enable-after-disable / static-
backend-startup bugs are all fixed.
2026-04-12 12:40:09 +02:00