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Merge pull request 'Catch up on merges the bus announced and never handed over (hq issue 266)' (#73) from fix/missed-merges-are-caught-up into main

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This commit was merged in pull request #73.
This commit is contained in:
mesh-admin
2026-10-05 23:33:18 +00:00
parent eda457f415 59f4d486b1
commit d1fc25f682
5 changed files with 451 additions and 28 deletions
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cmd/mesh-controller/missed_merges.go
+131
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@@ -0,0 +1,131 @@
package main
import (
"context"
"fmt"
"time"
"github.com/novox/mesh-controller/internal/inventory"
"github.com/novox/mesh-controller/internal/link"
)
// **A merge the bus announced and the controller never acted on is caught up** (novox/hq issue 266).
//
// The forge's poll announces every merge on the events stream, and the controller acts on what its
// consumer there hands it. On 2026-10-06 one merge was on the stream and never handed over: the bus
// server moved the consumer past it — a fault of consumers with several filters in the server the
// mesh ran — and the controller, which only acts on what it is handed, said nothing. The modules
// built from that repository stayed behind and were built by hand.
//
// So the stream is read back on a timer, on a consumer of its own filtered on merges alone, and every
// announcement older than mergeGrace is judged as SourceMoved would judge it. **No record of what
// was handled is kept, because none is needed**: acting on a merge marks every module it moved as
// looked at since, so an announcement already acted on reads as history and moves nothing. One that
// would still move something was never acted on — it is said, and acted on now.
const (
// mergeGrace is how long an announcement is left to the controller's own consumer before it is
// judged missed. That consumer hands over one event at a time, and a merge waits behind a build
// outcome that is being acted on; acting on a merge itself asks builds and does not wait for them.
mergeGrace = 10 * time.Minute
// mergeLookBack is how far back a pass reads. A merge missed longer ago than this was missed by a
// controller that was not running this, and is the operator's to look at, not a surprise rebuild.
mergeLookBack = 24 * time.Hour
// mergeCatchUpEvery is how often the stream is read back.
mergeCatchUpEvery = 5 * time.Minute
)
// merges is what reads back the forge's announcements; the link server, or a test's list.
type merges interface {
AnnouncedMerges(ctx context.Context, since time.Time) ([]link.AnnouncedMerge, error)
}
// catchingUpOnMerges reads back the forge's announcements on a timer, until the context ends.
func catchingUpOnMerges(ctx context.Context, open *stores, announced merges) {
f := following{open}
catalogued := func(ctx context.Context) ([]inventory.Entry, map[string][]inventory.ReadRepository, error) {
entries, err := open.inventory.Catalogued(ctx)
if err != nil {
return nil, nil, err
}
read, err := open.inventory.ReadRepositories(ctx)
return entries, read, err
}
failing := ""
tick := time.NewTicker(mergeCatchUpEvery)
defer tick.Stop()
for {
select {
case <-ctx.Done():
return
case <-tick.C:
}
err := catchUpOnMerges(ctx, time.Now(), announced, catalogued, f.SourceMoved, func(format string, args ...any) {
fmt.Printf(format+"\n", args...)
})
// A pass that cannot read says so once, not every five minutes, and says when it reads again.
why := ""
if err != nil {
why = err.Error()
}
if why != failing {
if why != "" {
fmt.Printf("merges the bus may not have handed over cannot be looked for: %s\n", why)
} else {
fmt.Println("merges the bus may not have handed over are looked for again")
}
failing = why
}
}
}
// catchUpOnMerges is one pass: every announcement older than mergeGrace that acting on would still
// move something is said and acted on, oldest first.
//
// Judged twice: once against the catalogue as the pass found it, and again just before acting,
// because acting on an earlier missed merge of the same repository may have moved what a later one
// would have.
func catchUpOnMerges(ctx context.Context, now time.Time, announced merges,
catalogued func(context.Context) ([]inventory.Entry, map[string][]inventory.ReadRepository, error),
act func(context.Context, link.SourceMoved) error, say func(string, ...any)) error {
all, err := announced.AnnouncedMerges(ctx, now.Add(-mergeLookBack))
if err != nil {
return err
}
entries, read, err := catalogued(ctx)
if err != nil {
return err
}
for _, a := range all {
if now.Sub(a.At) < mergeGrace {
continue
}
if len(wouldMove(a.SourceMoved, entries, read)) == 0 {
continue
}
if entries, read, err = catalogued(ctx); err != nil {
return err
}
moves := wouldMove(a.SourceMoved, entries, read)
if len(moves) == 0 {
continue
}
var names []string
for _, e := range moves {
names = append(names, e.Manifest.Module)
}
say("%s/%s merged into %s (%.8s), announced %s ago, and the controller never acted on it: the bus "+
"did not hand the announcement over (novox/hq issue 266). %s %s behind it; acting on it now",
a.Owner, a.Repo, a.Base, a.Commit, now.Sub(a.At).Round(time.Minute), readableList(names),
isAre(len(names)))
if err := act(ctx, a.SourceMoved); err != nil {
say("%s/%s moved to %.8s and the mesh could not act on it: %v; the next pass tries again",
a.Owner, a.Repo, a.Commit, err)
continue
}
if entries, read, err = catalogued(ctx); err != nil {
return err
}
}
return nil
}
cmd/mesh-controller/missed_merges_test.go
+180
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@@ -0,0 +1,180 @@
package main
import (
"context"
"errors"
"fmt"
"strings"
"testing"
"time"
"github.com/novox/mesh-controller/internal/inventory"
"github.com/novox/mesh-controller/internal/link"
)
// announcedList is the events stream's merges as a test gives them.
type announcedList []link.AnnouncedMerge
func (a announcedList) AnnouncedMerges(_ context.Context, since time.Time) ([]link.AnnouncedMerge, error) {
var out []link.AnnouncedMerge
for _, m := range a {
if !m.At.Before(since) {
out = append(out, m)
}
}
return out, nil
}
// aCatalogue is what the inventory holds, changed the way acting on a merge changes it: every module
// the merge moved is marked as looked at (inventory.SourceMoved writes source_seen = now()).
type aCatalogue struct {
entries []inventory.Entry
acted []string
fail error
}
func (c *aCatalogue) read(context.Context) ([]inventory.Entry, map[string][]inventory.ReadRepository, error) {
return append([]inventory.Entry(nil), c.entries...), nil, nil
}
func (c *aCatalogue) act(now func() time.Time) func(context.Context, link.SourceMoved) error {
return func(_ context.Context, m link.SourceMoved) error {
if c.fail != nil {
return c.fail
}
c.acted = append(c.acted, m.Repo+"@"+m.Commit[:8])
for _, moved := range wouldMove(m, c.entries, nil) {
for i := range c.entries {
if c.entries[i].Manifest.Module == moved.Manifest.Module {
c.entries[i].Source.Head = m.Commit
c.entries[i].Source.Seen = now()
}
}
}
return nil
}
}
func at(s string) time.Time {
t, err := time.Parse(time.RFC3339, s)
if err != nil {
panic(err)
}
return t
}
func announced(repo, commit, mergedAt, onTheBus string, paths ...string) link.AnnouncedMerge {
return link.AnnouncedMerge{
SourceMoved: link.SourceMoved{Owner: "novox", Repo: repo, Base: "main", Commit: commit,
MergedAt: mergedAt, Paths: paths,
CloneURL: "http://forge.internal:20000/novox/" + repo + ".git"},
At: at(onTheBus),
}
}
func built(module, repo, path, commit, seen string) inventory.Entry {
e := fromRepo(module, "http://forge.internal:20000/novox/"+repo+".git", path)
e.Source.BuiltFrom, e.Source.Head, e.Source.Seen = commit, commit, at(seen)
return e
}
// **novox/hq issue 266, as it happened.** The forge announced a merge of the tools repository on the
// events stream; the bus never handed it to the controller, which acted on the merges around it and
// not on this one, and said nothing. Read back from the stream, it is the one merge that would still
// move something — so it is said and acted on, once, and only after the controller's own consumer
// has had its time with it.
func TestAMergeTheBusNeverHandedOverIsActedOnLate(t *testing.T) {
cat := &aCatalogue{entries: []inventory.Entry{
built("mesh-tools", "mesh-tools", "", "8b789578aaaaaaaa", "2026-10-04T15:24:32Z"),
built("node-tools", "mesh-tools", "node-tools", "8b789578aaaaaaaa", "2026-10-04T15:24:32Z"),
// Acted on when it was announced: looked at after it was merged.
built("gitea", "mesh-catalog", "modules/gitea", "5c2157b8bbbbbbbb", "2026-10-05T22:39:21Z"),
}}
stream := announcedList{
// Nothing the mesh holds is built from the records repository.
announced("hq", "88f7f79fcccccccc", "2026-10-05T22:43:00Z", "2026-10-05T22:43:04Z", "04-ISSUES/x.md"),
// Acted on: its module was looked at since.
announced("mesh-catalog", "78328d4adddddddd", "2026-10-05T22:39:00Z", "2026-10-05T22:39:21Z", "modules/gitea/x.ts"),
// Never handed over.
announced("mesh-tools", "9730bd89c3e48d0e", "2026-10-05T22:46:47Z", "2026-10-05T22:47:06Z",
"node-tools/internal/console/console.go"),
}
var said []string
say := func(format string, args ...any) { said = append(said, fmt.Sprintf(format, args...)) }
clock := at("2026-10-05T22:50:00Z")
now := func() time.Time { return clock }
pass := func() {
t.Helper()
if err := catchUpOnMerges(context.Background(), clock, stream, cat.read, cat.act(now), say); err != nil {
t.Fatal(err)
}
}
pass()
if len(cat.acted) != 0 {
t.Fatalf("a merge three minutes old was taken from the controller's own consumer: %v", cat.acted)
}
clock = at("2026-10-05T22:58:00Z")
pass()
if strings.Join(cat.acted, ",") != "mesh-tools@9730bd89" {
t.Fatalf("acted on %v, wanted the one merge never handed over", cat.acted)
}
if len(said) != 1 || !strings.Contains(said[0], "novox/mesh-tools merged into main (9730bd89)") ||
!strings.Contains(said[0], "mesh-tools and node-tools are behind it") {
t.Fatalf("the missed merge was not said as one: %q", said)
}
clock = at("2026-10-05T23:03:00Z")
pass()
if len(cat.acted) != 1 || len(said) != 1 {
t.Fatalf("a merge acted on was acted on again: %v %q", cat.acted, said)
}
}
// A merge that changed none of the held modules' files moves nothing, so it is never "missed"; one
// that could not be acted on is said and tried again on the next pass.
func TestAMissedMergeThatCouldNotBeActedOnIsTriedAgain(t *testing.T) {
cat := &aCatalogue{
entries: []inventory.Entry{built("gitea", "mesh-catalog", "modules/gitea", "5c2157b8bbbbbbbb", "2026-10-05T20:00:00Z")},
fail: errors.New("the store is restarting"),
}
stream := announcedList{
announced("mesh-catalog", "aaaaaaaa11111111", "2026-10-05T21:00:00Z", "2026-10-05T21:00:10Z",
"modules/plex/module.json", "modules/plex/x.ts"),
announced("mesh-catalog", "bbbbbbbb22222222", "2026-10-05T21:10:00Z", "2026-10-05T21:10:10Z", "modules/gitea/x.ts"),
}
var said []string
say := func(format string, args ...any) { said = append(said, fmt.Sprintf(format, args...)) }
clock := at("2026-10-05T22:00:00Z")
now := func() time.Time { return clock }
if err := catchUpOnMerges(context.Background(), clock, stream, cat.read, cat.act(now), say); err != nil {
t.Fatal(err)
}
if len(said) != 2 || !strings.Contains(said[1], "could not act on it") {
t.Fatalf("a failed catch-up was not said: %q", said)
}
cat.fail = nil
clock = at("2026-10-05T22:05:00Z")
if err := catchUpOnMerges(context.Background(), clock, stream, cat.read, cat.act(now), say); err != nil {
t.Fatal(err)
}
if strings.Join(cat.acted, ",") != "mesh-catalog@bbbbbbbb" {
t.Fatalf("acted on %v, wanted only the merge that changed a held module", cat.acted)
}
}
// A merge older than the look-back is left to the operator: a controller that did not run this
// missed it, and acting on it days later would be a surprise rebuild.
func TestAMergeOlderThanTheLookBackIsLeftAlone(t *testing.T) {
cat := &aCatalogue{entries: []inventory.Entry{built("gitea", "mesh-catalog", "modules/gitea", "5c2157b8bbbbbbbb", "2026-10-01T00:00:00Z")}}
stream := announcedList{announced("mesh-catalog", "cccccccc33333333", "2026-10-03T00:00:00Z", "2026-10-03T00:00:05Z", "modules/gitea/x.ts")}
clock := at("2026-10-05T22:00:00Z")
if err := catchUpOnMerges(context.Background(), clock, stream, cat.read, cat.act(func() time.Time { return clock }),
func(string, ...any) {}); err != nil {
t.Fatal(err)
}
if len(cat.acted) != 0 {
t.Fatalf("a merge of three days ago was acted on: %v", cat.acted)
}
}
cmd/mesh-controller/push.go
+3
View File
@@ -127,6 +127,9 @@ func serve(ctx context.Context) error {
if err := server.Follows(following{open}); err != nil {
return err
}
// And the merges the bus announced and never handed over, read back on a timer and acted on late
// rather than never (novox/hq issue 266).
go catchingUpOnMerges(ctx, open, server)
// And a catalogue that has just started, asking for what it missed. The same type answers
// both: what a build meant and what the builds were are two questions about one record.
if err := server.Answers(following{open}); err != nil {
cmd/mesh-controller/upgrades.go
+58 -28
View File
@@ -8,6 +8,7 @@ import (
"path"
"regexp"
"strings"
"sync"
"time"
"github.com/novox/mesh-controller/internal/catalogue"
@@ -266,6 +267,11 @@ func notNow(err error) error {
// (novox/hq 04-ISSUES/131). Nothing is pushed here: what a finished build does to the machines
// running the module is the upgrade's decision, taken when the catalogue announces it.
func (f following) SourceMoved(ctx context.Context, m link.SourceMoved) error {
// One merge acted on at a time, whoever hands it over: the bus, or the catch-up that reads back
// what the bus did not hand over (novox/hq issue 266). Each judges against what the other wrote.
actingOnMerges.Lock()
defer actingOnMerges.Unlock()
inv := f.open.inventory
entries, err := inv.Catalogued(ctx)
if err != nil {
@@ -276,34 +282,7 @@ func (f following) SourceMoved(ctx context.Context, m link.SourceMoved) error {
return notNow(err)
}
// Two kinds of module are affected by one merge, and they are affected differently.
//
// A module **built from** this repository and branch has moved: the mesh records the new commit
// as what its source now has, and only what the merge actually changed is rebuilt. A module that
// only **packages source from** it has not moved — its own source is somewhere else, at the
// commit it already records — so it is rebuilt and its record left alone. Writing this commit as
// its source would make it permanently behind a repository its manifest does not come from.
var from, packaging []inventory.Entry
already := 0
for _, e := range entries {
switch {
case sourceIs(e.Source, m):
if e.Source.BuiltFrom == m.Commit {
already++
continue
}
// **A merge older than the last look at the source is history, not a move.** The forge
// announces what it finds merged, and an old merge surfacing late would otherwise move
// the recorded head backwards and rebuild everything built from that repository, once
// per old merge (2026-09-28).
if isHistory(m.MergedAt, e.Source.Seen) {
continue
}
from = append(from, e)
case readsFrom(read[e.Manifest.Module], m):
packaging = append(packaging, e)
}
}
from, packaging, already := mergeCandidates(m, entries, read)
if len(from) == 0 && len(packaging) == 0 {
// "Already built from it" and "nothing reads it" are different facts, and reading the first
// as the second sends somebody looking for a broken trigger when the mesh is up to date.
@@ -438,6 +417,57 @@ func (f following) SourceMoved(ctx context.Context, m link.SourceMoved) error {
return nil
}
// actingOnMerges keeps one merge acted on at a time (novox/hq issue 266).
var actingOnMerges sync.Mutex
// mergeCandidates is what one merge could move, judged against what the catalogue holds.
//
// Two kinds of module are affected by one merge, and they are affected differently.
//
// A module **built from** this repository and branch has moved: the mesh records the new commit as
// what its source now has, and only what the merge actually changed is rebuilt. A module that only
// **packages source from** it has not moved — its own source is somewhere else, at the commit it
// already records — so it is rebuilt and its record left alone. Writing this commit as its source
// would make it permanently behind a repository its manifest does not come from. `already` counts
// the modules built from this repository that are already built from this very commit.
func mergeCandidates(m link.SourceMoved, entries []inventory.Entry,
read map[string][]inventory.ReadRepository) (from, packaging []inventory.Entry, already int) {
for _, e := range entries {
switch {
case sourceIs(e.Source, m):
if e.Source.BuiltFrom == m.Commit {
already++
continue
}
// **A merge older than the last look at the source is history, not a move.** The forge
// announces what it finds merged, and an old merge surfacing late would otherwise move
// the recorded head backwards and rebuild everything built from that repository, once
// per old merge (2026-09-28).
if isHistory(m.MergedAt, e.Source.Seen) {
continue
}
from = append(from, e)
case readsFrom(read[e.Manifest.Module], m):
packaging = append(packaging, e)
}
}
return from, packaging, already
}
// wouldMove is the modules built from the merged repository that acting on this merge would mark as
// moved and rebuild — SourceMoved's judgement, made without acting (novox/hq issue 266). Empty for a
// merge already acted on: acting marks each of them as looked at, so the merge then reads as history.
//
// **Only the modules built from it, never the ones that merely package source from it.** Acting
// records nothing about those, so a merge acted on would go on reading as unacted for them, and be
// acted on again on every look. A merge that moves both is caught by the first kind, and acting on it
// rebuilds the second as well.
func wouldMove(m link.SourceMoved, entries []inventory.Entry,
read map[string][]inventory.ReadRepository) []inventory.Entry {
from, _, _ := mergeCandidates(m, entries, read)
return whatTheMergeTouched(from, entries, m)
}
// sourceIs is whether a recorded source is the repository and branch a merge announced. A source on
// the git seat is recorded as its path on the forge; one elsewhere as the URL it was cloned from.
// An empty recorded ref is the repository's default branch, which is what a merge into the base