Say when the node composes again after a seat that did not answer, say what a long pass waits on, and serve the verb compose (issue 774)

On 2026-10-31 ace's route-proxy said only that the vault could not be asked, and ace said nothing for five minutes
while a pass waited after the vault restarted; the retry that already existed was invisible. A refusal for a seat or
a read that did not answer now says when the node composes again ("the node composes again at HH:MM:SS (try N)"), a
retry pass says it starts, a pass that runs on says every minute what it waits on, and the node-engine's verb
compose makes a pass now and says how it went, so a person recovers without a restart.
This commit is contained in:
2026-10-31 00:56:47 +01:00
parent 91fb323ce0
commit 9c15610f70
7 changed files with 255 additions and 17 deletions
+34
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@@ -18,6 +18,7 @@ import (
"github.com/novox/mesh-host/internal/accounts"
"github.com/novox/mesh-host/internal/apply"
"github.com/novox/mesh-host/internal/link"
"github.com/novox/mesh-host/internal/selfcompose"
"github.com/novox/mesh-host/internal/store"
)
@@ -292,3 +293,36 @@ func compositionFrom(current *agentNow) func(module, digest string, diff bool) (
return ag.Composition(ctx, module, digest, diff)
}
}
// composeReadFor bounds the verb compose's wait for its pass: a pass that waits on a seat longer says what it waits on.
const composeReadFor = 2 * time.Minute
// composeFrom answers the verb compose (issue 774): a pass of the composer that runs now, and with module that module's
// apply tried again by the node agent; refused in words while the node composes nothing of its own.
func composeFrom(current *agentNow, composer *atomic.Pointer[selfcompose.Composer]) func(module string) (any, error) {
return func(module string) (any, error) {
c := composer.Load()
if c == nil {
return nil, errors.New("this node composes none of its own modules now (it applies the controller's " +
"compositions, or its node agent is starting), so there is no pass to make")
}
ag := current.get()
if module != "" {
if ag == nil || !ag.Placed("")[module] {
return nil, fmt.Errorf("%s has no want on this machine, so there is no apply of it to try again", module)
}
}
ctx, cancel := context.WithTimeout(context.Background(), composeReadFor)
defer cancel()
pass, err := c.ComposeNow(ctx)
if err != nil {
return nil, err
}
out := map[string]any{"pass": pass}
if module != "" {
ag.Retry(module)
out["retried"] = module
}
return out, nil
}
}
+1
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@@ -1142,6 +1142,7 @@ func runLink(ctx context.Context, opts options) error {
go reconcileActs(ctx, queue.Acts)
current := &agentNow{}
queue.Acts.Composition = compositionFrom(current)
queue.Acts.Compose = composeFrom(current, &composerNow)
setRunsHere(runsFromAgent(current))
factsOfNow := func(ctx context.Context, ag *agent.Agent) {
sayFacts(ctx, opts, mine.Membership.Signer, queue, say, ag)
+6
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@@ -668,6 +668,7 @@ func nodeAgent(ctx context.Context, opts options, signer ed25519.PublicKey, trus
}
if composer != nil {
machinesNow.Store(composer) // the machines a failing network part points at, by the placements (issue 774)
composerNow.Store(composer) // what the verb compose asks a pass of, this run's alone
composes.set(delivery.ComposesOwn)
env.Composed, env.SelfComposed, env.Trusted, env.Policy = composer, true, nil, composer.Policy
env.HoldsData = composer.HoldsData // what runs from the kept declaration says Data as its manifest does
@@ -692,6 +693,7 @@ func nodeAgent(ctx context.Context, opts options, signer ed25519.PublicKey, trus
stopRun()
cancel()
current.set(nil)
composerNow.Store(nil)
if ctx.Err() != nil {
return
}
@@ -814,6 +816,10 @@ func busyModules() []string {
// (writeHealthReport); nil on a node that does not compose its own, whose parts then name no target.
var machinesNow atomic.Pointer[selfcompose.Composer]
// composerNow is the composer of the run that composes the node's own now, nil while the node applies the controller's
// compositions or no run is going: what the verb compose asks a pass of (issue 774).
var composerNow atomic.Pointer[selfcompose.Composer]
// keptRetired says the kept declaration is read no more: every module the seat's placement puts on this node has a have of
// its own (placedAllHave), so what runs is the agent's alone (ADR 0550 §2, design 47's L3 s9).
var keptRetired atomic.Bool
+10
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@@ -40,6 +40,8 @@ const (
ActSetuidSearch = "setuid-search"
// ActComposition reads a module's composition beside what runs of it; read-only, no warrant (issue 774).
ActComposition = "composition"
// ActCompose composes the node now, the recovery of a failed composition (issue 774).
ActCompose = "compose"
)
// The states of an act.
@@ -132,6 +134,9 @@ type HandActs struct {
// Composition reads one module's composition beside what runs of it, read-only (the verb composition, issue 774):
// the latest of its want's build or the one whose digest is given, and with diff the resources that differ.
Composition func(module, digest string, diff bool) (any, error)
// Compose makes a pass of the node's composition now and says how it went; with module, its apply is also tried
// again (the verb compose, issue 774).
Compose func(module string) (any, error)
// Say says one of the seat's events, asked, done or refused; nil says nothing.
Say func(event string, body any)
Now func() time.Time
@@ -190,6 +195,11 @@ func (h *HandActs) Call(c EngineCall) (any, error) {
diff = b
}
return h.Composition(arg("module"), arg("digest"), diff)
case ActCompose:
if h.Compose == nil {
return nil, errors.New("this engine composes nothing on a call yet: its node agent has not started")
}
return h.Compose(arg("module"))
case "acts":
if id := arg("id"); id != "" {
return h.Act(id)
+5 -1
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@@ -239,7 +239,8 @@ func TestALinkThatHearsHandOversIsGivenTheQueues(t *testing.T) {
JudgeDirectories: func(by string) (string, error) { return "judged for " + by, nil },
Composition: func(module, digest string, diff bool) (any, error) {
return map[string]any{"module": module, "digest": digest, "diff": diff}, nil
}}
},
Compose: func(module string) (any, error) { return map[string]any{"composed": true, "retried": module}, nil }}
for _, row := range []struct{ verb, subject, want string }{
{"judge-directories", "mesh.seat.node-engine.call.judge-directories.n1.shanks~node-tools", `"said":"judged for shanks.node-tools"`},
{"judge-directories", EngineToolSubject("judge-directories", "n1"), `"said":"judged for unproven"`},
@@ -248,6 +249,9 @@ func TestALinkThatHearsHandOversIsGivenTheQueues(t *testing.T) {
// The read verb composition (issue 774) takes its module, digest and diff, as a word or a boolean.
{"composition", EngineToolSubject("composition", "n1") + " " + `{"module":"postgres","digest":"sha256:a","diff":true}`, `"diff":true,"digest":"sha256:a","module":"postgres"`},
{"composition", EngineToolSubject("composition", "n1") + " " + `{"module":"postgres","diff":"true"}`, `"diff":true,"digest":"","module":"postgres"`},
// The recovery verb compose (issue 774) makes a pass now, with a module's apply tried again when named.
{"compose", EngineToolSubject("compose", "n1"), `"composed":true,"retried":""`},
{"compose", EngineToolSubject("compose", "n1") + " " + `{"module":"route-proxy"}`, `"retried":"route-proxy"`},
{"unserved", "mesh.seat.node-engine.call.unserved.n1.x", `"error":"the node seat node-engine serves no verb \"unserved\""`},
} {
subject, body, ok := strings.Cut(row.subject, " ")
+142 -13
View File
@@ -127,6 +127,58 @@ type Composer struct {
missed atomic.Uint64
// owed is set when a pass refused for a bus that did not answer: the composer composes again after a bound.
owed atomic.Bool
// tries counts the passes owed in a row, and wait is the bound before the next (LaterWait): set by the pass that owes
// one, so the refusal it marks says when the node composes again (issue 774, 2026-10-31). Under mu.
tries int
wait time.Duration
// asked are the compose verb's asks (ComposeNow), each answered once the pass it asks is made.
asked chan chan Pass
// last is how the last pass went, under mu.
last Pass
}
// Pass is how one pass went, as the node-engine's verb compose answers it.
type Pass struct {
// At is when the pass ended.
At time.Time `json:"at"`
// Refused is why the node composed none of its modules; empty when it composed.
Refused string `json:"refused,omitempty"`
// Held is each module refused alone, with why.
Held map[string]string `json:"held,omitempty"`
// Handed is how many compositions the pass handed the agent that differ from what it handed before.
Handed int `json:"handed"`
// Again is when the node composes again on its own, after a seat or a read that did not answer; zero when it does
// not need to.
Again time.Time `json:"again,omitempty"`
}
// passSaysEvery is how often a pass that runs on says, in the journal, how long it has run and what it waits on.
var passSaysEvery = time.Minute
// owe marks a pass owed after a seat or a read that did not answer: the next wait of the growing bound (LaterWait), and
// the words that say when the node composes again, for the refusal it marks.
func (c *Composer) owe() string {
c.mu.Lock()
defer c.mu.Unlock()
c.wait = LaterWait(c.tries)
c.tries++
c.owed.Store(true)
return fmt.Sprintf("the node composes again at %s (try %d)", time.Now().Add(c.wait).Format("15:04:05"), c.tries)
}
// paid clears what owe marked: the pass composed, or owes nothing.
func (c *Composer) paid() {
c.mu.Lock()
defer c.mu.Unlock()
c.tries, c.wait = 0, 0
c.owed.Store(false)
}
// waitNow is the bound before the pass owed, and its try.
func (c *Composer) waitNow() (time.Duration, int) {
c.mu.Lock()
defer c.mu.Unlock()
return c.wait, c.tries
}
// note counts err when it is the bus not answering, and returns it.
@@ -150,7 +202,26 @@ func New(env Env) *Composer {
}
return &Composer{env: env, wants: map[string]delivery.Want{}, placements: map[string]delivery.Placement{},
records: map[string]delivery.NodeRecord{}, inOwn: map[string]bool{}, modules: map[string]delivery.Module{}, values: map[string]map[string]any{},
manifests: map[string][]byte{}, archives: map[string][]byte{}, handed: map[string]string{}, sealedOwn: map[string]ownSealed{}}
manifests: map[string][]byte{}, archives: map[string][]byte{}, handed: map[string]string{}, sealedOwn: map[string]ownSealed{},
asked: make(chan chan Pass, 8)}
}
// ComposeNow asks the composer for a pass now (the node-engine's verb compose, issue 774): the growing bound after a seat
// that did not answer starts again, and the answer is how the pass went. Refused in words when no pass is made before
// ctx ends: the composer not running, or its inputs not all read yet.
func (c *Composer) ComposeNow(ctx context.Context) (Pass, error) {
reply := make(chan Pass, 1)
select {
case c.asked <- reply:
case <-ctx.Done():
return Pass{}, errors.New("the node's composer took no ask: it composes nothing now")
}
select {
case p := <-reply:
return p, nil
case <-ctx.Done():
return Pass{}, fmt.Errorf("the node made no pass in time; it waits on %s", c.waitingOn())
}
}
// ownSealed is one own secret's sealed value at a generation and the key it is sealed to.
@@ -270,7 +341,7 @@ func (c *Composer) Watch(ctx context.Context, _ string) (<-chan agent.Update, er
// A pass refused for a bus that did not answer is made again after a bound (laterAgain), not kept until another
// input moves (issue 1126, 2026-10-28).
var again <-chan time.Time
tries := 0
var replies []chan Pass
for {
// Drain whatever came, then compose once for all of it.
select {
@@ -279,6 +350,16 @@ func (c *Composer) Watch(ctx context.Context, _ string) (<-chan agent.Update, er
case <-again:
again = nil
dirty = true
_, try := c.waitNow()
c.env.Say(fmt.Sprintf("the node composes again now (try %d), after a seat or a read that did not answer", try+1))
case reply := <-c.asked:
// Asked by hand (the verb compose): composed now, the bound starting again.
replies = append(replies, reply)
c.mu.Lock()
c.tries = 0
c.mu.Unlock()
again = nil
dirty = true
case t := <-merged:
if !t.ok {
c.env.Say(fmt.Sprintf("the watch of %s ended; the node composes no more until its agent starts again", ins[t.in].bucket))
@@ -318,13 +399,19 @@ func (c *Composer) Watch(ctx context.Context, _ string) (<-chan agent.Update, er
}
}
if c.owed.Load() {
wait := LaterWait(tries)
tries++
wait, _ := c.waitNow()
c.env.Say(fmt.Sprintf("the node composes again in %s: a read on the bus did not answer", wait))
again = time.After(wait)
} else {
tries, again = 0, nil
again = nil
}
c.mu.Lock()
last := c.last
c.mu.Unlock()
for _, r := range replies {
r <- last
}
replies = nil
if !c.caughtSent() {
select {
case out <- agent.Update{Caught: true}:
@@ -518,6 +605,35 @@ func (c *Composer) takeValue(u agent.Update) {
// compose composes the node once and answers the updates to hand: each composition whose digest differs from the one
// handed, and a deletion for each handed one no want names any more.
func (c *Composer) compose(ctx context.Context) []agent.Update {
pass := Pass{}
defer func() {
pass.At = time.Now()
if c.owed.Load() {
wait, _ := c.waitNow()
pass.Again = pass.At.Add(wait)
}
c.mu.Lock()
c.last = pass
c.mu.Unlock()
}()
// A pass that runs on says so, and what it waits on, every passSaysEvery (issue 774, 2026-10-31: ace said nothing for
// five minutes while a pass waited after the vault restarted).
began := time.Now()
long, stopLong := context.WithCancel(ctx)
defer stopLong()
go func() {
t := time.NewTicker(passSaysEvery)
defer t.Stop()
for {
select {
case <-long.Done():
return
case <-t.C:
c.env.Say(fmt.Sprintf("the node's composition has run for %s and waits on %s",
time.Since(began).Round(time.Second), c.waitingOn()))
}
}
}()
c.mu.Lock()
fps := map[string]string{}
kept := map[string]string{}
@@ -542,7 +658,7 @@ func (c *Composer) compose(ctx context.Context) []agent.Update {
// The catalogue no longer places it: the agent returns to the controller's compositions (endWhenUnplaced), and
// this is no refusal of what it runs (issue 1126, the seed's revert).
c.sayOnce("this node's key in the seat's placement state is gone: it composes nothing of its own, and keeps running what it runs")
c.owed.Store(false) // nothing of its own to compose, so no pass is owed and no timer armed again
c.paid() // nothing of its own to compose, so no pass is owed and no timer armed again
return nil
}
// Composed from the build its want names (frombus.Scope.KeptAt, issue 1126).
@@ -581,11 +697,20 @@ func (c *Composer) compose(ctx context.Context) []agent.Update {
return nil
}
if err != nil {
why := fmt.Sprintf("%v", err)
// A bus that did not answer past every try is no answer: composed again after a bound (issue 1126, 2026-10-28),
// and the refusal says when (issue 774, 2026-10-31). A refusal is final until an input moves.
if BusFailed(err) {
why += "; " + c.owe()
} else {
c.paid()
}
pass.Refused = why
// Said before the agent marks the modules: the marks read each have first, which a paused bus delays.
c.sayOnce(fmt.Sprintf("the node cannot compose its modules, and keeps running what it runs: %v", err))
c.refused(fmt.Sprintf("%v", err), nil)
// A bus that did not answer past every try is no answer: composed again after a bound (issue 1126, 2026-10-28).
c.owed.Store(BusFailed(err))
c.sayOnce("the node cannot compose its modules, and keeps running what it runs: " + why)
done := c.waiting("the agent marking each wanted module's have")
c.refused(why, nil)
done()
return nil
}
// The boxes it runs, slot by slot: read before c.mu is taken, since the agent's lock is taken to read what runs.
@@ -596,14 +721,17 @@ func (c *Composer) compose(ctx context.Context) []agent.Update {
if c.missed.Load() > missed {
// A have of what runs the bus did not answer for: its boxes would be the vault's, sealed again, and the
// composition another; nothing is handed, and the pass is made again after a bound (issue 1126, 2026-10-28).
c.sayOnce("the node composes nothing new for now, and keeps running what it runs: the have of what it runs did not answer on the bus")
c.owed.Store(true)
pass.Refused = "the have of what it runs did not answer on the bus; " + c.owe()
c.sayOnce("the node composes nothing new for now, and keeps running what it runs: " + pass.Refused)
return nil
}
c.owed.Store(false)
c.paid()
pass.Held = held
// A module refused alone is held: it keeps what it runs, its have says why, and every other module is applied (issue
// 1126: one module's refusal froze the whole node).
done := c.waiting("the agent marking each held module's have")
c.refused("", held)
done()
if len(held) == 0 {
c.sayOnce("")
} else {
@@ -658,6 +786,7 @@ func (c *Composer) compose(ctx context.Context) []agent.Update {
out = append(out, agent.Update{Key: key, Deleted: true, Revision: c.rev})
}
}
pass.Handed = len(out)
return out
}
+57 -3
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@@ -6,6 +6,7 @@ import (
"encoding/base64"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"os"
"slices"
@@ -238,6 +239,20 @@ func TestTheNodeComposesItsWantsFromTheBus(t *testing.T) {
}
}
b.mu.Unlock()
// Issue 774, 2026-10-31: the verb compose makes a pass now and says how it went; a composer that runs no watch
// makes none, and says so rather than waiting.
madeBefore := composed.Load()
cctx, ccancel := context.WithTimeout(ctx, 5*time.Second)
nowPass, err := c.ComposeNow(cctx)
ccancel()
if err != nil || nowPass.At.IsZero() || nowPass.Refused != "" || !nowPass.Again.IsZero() || composed.Load() == madeBefore {
t.Errorf("compose now: %+v (%v), %d pass(es) made; want one pass, composed", nowPass, err, composed.Load()-madeBefore)
}
idle, icancel := context.WithTimeout(ctx, 20*time.Millisecond)
if _, err := New(env).ComposeNow(idle); err == nil {
t.Error("a composer that watches nothing answered compose now")
}
icancel()
lemursKey, _ := delivery.ComposedKey("n1", "lemurs", fp)
nodeKey, _ := delivery.ComposedNodeKey("n1")
if !got[lemursKey] || !got[nodeKey] || len(got) != 2 {
@@ -277,15 +292,27 @@ func TestTheNodeComposesItsWantsFromTheBus(t *testing.T) {
c.mu.Unlock()
return c2, &refusals
}
setFor(t, &passSaysEvery, 5*time.Millisecond)
for name, row := range map[string]struct {
failures int // reads failing before the bus answers
cancel bool
composes bool
fail error // what each failing read says; JetStream not enabled when nil
slow time.Duration // each failing read takes this long
// again: the refusal says when the node composes again, and a pass is owed (issue 774, 2026-10-31: ace's
// route-proxy said only "the vault's own could not be asked ... context deadline exceeded").
again bool
}{
"the bus paused for one read": {failures: 1, composes: true},
"the bus paused past every try": {failures: 100},
"the bus paused past every try": {failures: 100, again: true},
"the run ended mid-pass": {failures: 100, cancel: true},
"the vault did not answer in time": {failures: 100, again: true, slow: 30 * time.Millisecond,
fail: fmt.Errorf("the vault's own could not be asked: no answer from mesh.seat.mesh-vault.call.own.node~n1: %w", context.DeadlineExceeded)},
"a refusal": {failures: 100, fail: errors.New("nats says ${dir:mesh-state}, and nats declares no directory")},
} {
b.mu.Lock()
saidBefore := len(b.said)
b.mu.Unlock()
failed := 0
pctx, pcancel := context.WithCancel(ctx)
c2, refusals := fresh(func(gctx context.Context, bucket, key string) ([]byte, error) {
@@ -295,6 +322,10 @@ func TestTheNodeComposesItsWantsFromTheBus(t *testing.T) {
pcancel()
return nil, fmt.Errorf("the vault's own could not be asked: %w", context.Canceled)
}
time.Sleep(row.slow)
if row.fail != nil {
return nil, fmt.Errorf("the revisions of %s in %s: %w", key, bucket, row.fail)
}
return nil, fmt.Errorf("the revisions of %s in %s: %w", key, bucket, nats.ErrJetStreamNotEnabled)
}
b.mu.Lock()
@@ -303,14 +334,37 @@ func TestTheNodeComposesItsWantsFromTheBus(t *testing.T) {
})
handed := c2.compose(pctx)
pcancel()
tries := 1 + len(composeAgain) // a bus paused for a moment is tried again at once; a timeout or a refusal is not
if row.fail != nil {
tries = 1
}
switch {
case row.composes && (len(handed) == 0 || len(*refusals) != 0):
t.Errorf("%s: handed %d, refusals %q; want composed and nothing refused", name, len(handed), *refusals)
case !row.composes && !row.cancel && (len(*refusals) != 1 || failed != 1+len(composeAgain)):
t.Errorf("%s: refusals %q after %d reads; want one refusal after %d tries", name, *refusals, failed, 1+len(composeAgain))
case !row.composes && !row.cancel && (len(*refusals) != 1 || failed != tries):
t.Errorf("%s: refusals %q after %d reads; want one refusal after %d tries", name, *refusals, failed, tries)
case row.cancel && len(*refusals) != 0:
t.Errorf("%s: a pass whose run ended refused %q", name, *refusals)
}
if !row.composes && !row.cancel && len(*refusals) > 0 {
says := strings.Contains((*refusals)[0], "; the node composes again at ") && strings.HasSuffix((*refusals)[0], "(try 1)")
if says != row.again || c2.owed.Load() != row.again || (c2.last.Again.IsZero() == row.again) || c2.last.Refused != (*refusals)[0] {
t.Errorf("%s: refused %q, owes a pass %v, last pass %+v; want the time it composes again said and owed: %v",
name, (*refusals)[0], c2.owed.Load(), c2.last, row.again)
}
}
// A pass that runs on says so, and what it waits on (issue 774, 2026-10-31: ace was silent for five minutes).
if row.slow > 0 {
b.mu.Lock()
long := false
for _, line := range b.said[saidBefore:] {
long = long || strings.Contains(line, "the node's composition has run for ") && strings.Contains(line, " and waits on ")
}
b.mu.Unlock()
if !long {
t.Errorf("%s: a pass that ran on said nothing of what it waits on", name)
}
}
}
if !Transient(fmt.Errorf("the manifest of avahi: the revisions of x in mesh-delivery-indexer_manifests: nats: jetstream not enabled")) ||
!Transient(fmt.Errorf("x: %w", nats.ErrNoResponders)) || Transient(fmt.Errorf("nats says ${dir:mesh-state}, and nats declares no directory")) ||