An upgrade refits the judge an earlier server init installed

A v0.14.6 install on fewer than eight cores refused every request until
its judge was given cores by hand, and upgrading did not change that. The
judge keeper, on the leader, now finds a judge whose entry is exactly what
init before v0.14.7 wrote: one llama.cpp CPU profile, an 8192 context and
nothing else, 2 or 4 GB, none to two cores. It gives the judge 2 GB,
--cache-ram 0 and cores by init's rule through modelsvc.SetProfiles, then
restarts its ready replicas. The replica count is left as it is. A judge
whose entry differs is left alone, and the log says so once.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

BACKLOG.md

@@ -21,9 +21,8 @@ What is left, most needed first. The detail is in the item each names.
 
 1. ~~**J1**~~ — done 2026-10-16: a restart no longer refused for room
    another restart was giving back.
-2. **J5** — an upgrade leaves an earlier install's judge as it was. A
-   v0.14.6 install on fewer than eight cores refuses every request until
-   fixed by hand. (S)
+2. ~~**J5**~~ — done 2026-10-16: an upgrade refits an earlier install's
+   judge by itself.
 3. **I3** — what llmgw adds to a request, measured, in the README. (S)
 4. **I4** — several keys for one outside provider. (S)
 5. **J2** — a judge the leader adds by itself is sized as init's is. (S)
@@ -1601,7 +1600,15 @@ models the nodes already have keep serving and new ones wait for it.
 - Done when: with the first machine powered off, a model added then is
   fetched and served.
 
-### J5. An upgrade corrects an earlier install's judge (S)
+### J5. An upgrade corrects an earlier install's judge (S) — done 2026-10-16
+Built in the judge keeper (`internal/cli/judgekeeper.go`, `refit`), on the
+leader: a judge whose entry is exactly what init before v0.14.7 wrote is
+given 2 GB, `--cache-ram 0` and cores by init's rule (`refitCores`: up to
+four for one judge, two each for more), through `modelsvc.SetProfiles`,
+and its ready replicas are restarted (after J1). Its replica count is left
+as it is. One that differs is left alone and said once in the log. The
+original item follows.
+
 v0.14.6 and earlier installed two judges reserving no cores or one, with
 2 or 4 GB and the prompt cache on. On fewer than eight cores every judgment
 missed its 5 s budget and every request was refused. v0.14.7's notes say

CHANGELOG.md

@@ -28,6 +28,12 @@ APIs change between minors without a deprecation period.
 
 ### Fixed
 
+- **An upgrade refits the judge an earlier `server init` installed.** Upgrading to v0.14.7 left such a judge as it was:
+  no cores or one, 2 or 4 GB, the prompt cache on. On fewer than eight cores every request was refused until it was
+  fixed by hand. Now the leader finds a judge whose entry is exactly what an earlier init wrote and gives it 2 GB, no
+  prompt cache and cores by today's rule (up to four for one judge, two each for more). It then restarts the judge's
+  replicas onto that. The number of replicas is left as it is. A judge whose entry was changed by hand is left alone,
+  and the log says so once.
 - **A restart is no longer refused for room another restart is giving back.** With every core of a node reserved, two
   models restarted together, one to need more and one less (as after `ctl model resources` on a judge and a starter),
   had the first refused: "fits on no node even with this replica stopped", though the second was about to give back

internal/cli/judgekeeper.go

@@ -32,6 +32,19 @@ type judgeKeeper struct {
 	// tried is when each judge was last asked for, so one that cannot be
 	// fetched is not asked for again on every look.
 	tried map[string]time.Time
+
+	// What refitting an earlier install's judge needs: the catalog to change
+	// its profile in, the replicas to restart, and the nodes' CPUs. Any nil
+	// leaves judges as they are.
+	profiles interface {
+		SetProfiles(ctx context.Context, name string, profiles []catalog.Profile, by string) (catalog.Model, error)
+	}
+	restart  func(ids ...string) error
+	replicas func(model string) []string
+	nodeCPUs func() []int
+	// looked is each judge already refitted or found changed by hand, so
+	// each is said once.
+	looked map[string]bool
 }
 
 // judgeRetry is how long a judge whose serving failed waits before it is
@@ -69,6 +82,7 @@ func (k *judgeKeeper) check() {
 	have := map[string]bool{}
 	for _, m := range k.models() {
 		have[m.Name] = true
+		k.refit(m)
 	}
 	busy := map[string]bool{}
 	for _, j := range k.serve.Jobs() {
@@ -114,3 +128,88 @@ func (k *judgeKeeper) check() {
 			"judge", name, "repo", kj.Repo, "file", kj.File, "job", job.ID)
 	}
 }
+
+// refit moves a judge an earlier `server init` installed to what init
+// installs now, and restarts its replicas onto it. Those judges reserved no
+// cores or one, 2 or 4 GB, and ran llama.cpp's prompt cache: on fewer than
+// eight cores every judgment missed its 5 s budget and fail: closed refused
+// every request, until fixed by hand. A judge whose profile differs in any
+// other way was set by somebody, and is left as it is, said once.
+func (k *judgeKeeper) refit(m catalog.Model) {
+	if k.profiles == nil || k.restart == nil || k.replicas == nil || m.Name != defaultJudge || !m.IsGuard() {
+		return
+	}
+	if k.looked == nil {
+		k.looked = map[string]bool{}
+	}
+	if k.looked[m.Name] {
+		return
+	}
+	k.looked[m.Name] = true
+	if !earlierInitJudge(m) {
+		if len(m.Profiles) != 1 || !slices.Contains(m.Profiles[0].Args, "--cache-ram") {
+			k.log.Info("the judge's profile is not one init wrote; left as it is",
+				"judge", m.Name, "see", "llmgw ctl model resources "+m.Name)
+		}
+		return
+	}
+	var cpus []int
+	if k.nodeCPUs != nil {
+		cpus = k.nodeCPUs()
+	}
+	p := m.Profiles[0]
+	p.MinMemoryGB = judgeMemoryGB
+	p.CPUCores = refitCores(m.Scaling.Min, cpus)
+	p.Args = []string{"--ctx-size", "8192", "--cache-ram", "0"}
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	if _, err := k.profiles.SetProfiles(ctx, m.Name, []catalog.Profile{p}, "llmgw (the judge an earlier init installed)"); err != nil {
+		k.log.Warn("could not refit the judge an earlier init installed", "judge", m.Name, "err", err)
+		k.looked[m.Name] = false
+		return
+	}
+	ids := k.replicas(m.Name)
+	if len(ids) > 0 {
+		if err := k.restart(ids...); err != nil {
+			k.log.Warn("refitted the judge, but could not restart it", "judge", m.Name, "err", err)
+		}
+	}
+	k.log.Info("refitted the judge an earlier init installed", "judge", m.Name,
+		"memory_gb", p.MinMemoryGB, "cpu_cores", p.CPUCores, "replicas_restarted", len(ids))
+}
+
+// earlierInitJudge is whether a judge's entry is exactly what `server init`
+// before v0.14.7 wrote: one llama.cpp profile on CPUs, an 8192 context and
+// no other args, 2 or 4 GB, none to two cores.
+func earlierInitJudge(m catalog.Model) bool {
+	if len(m.Profiles) != 1 {
+		return false
+	}
+	p := m.Profiles[0]
+	return p.Name == "cpu" && p.Engine == "llamacpp" && p.GPUClass == "" && p.GPU == nil &&
+		len(p.NodeSelector) == 0 && slices.Equal(p.Args, []string{"--ctx-size", "8192"}) &&
+		(p.MinMemoryGB == 2 || p.MinMemoryGB == 4) && p.CPUCores >= 0 && p.CPUCores <= 2
+}
+
+// refitCores is a judge replica's cores by init's rule: up to four for the
+// one judge of a cluster, two each where there are more, fewer where the
+// smallest node cannot hold them all.
+func refitCores(replicas int, cpus []int) int {
+	smallest := 0
+	for _, c := range cpus {
+		if c > 0 && (smallest == 0 || c < smallest) {
+			smallest = c
+		}
+	}
+	if replicas <= 1 {
+		if smallest == 0 {
+			return judgeCores
+		}
+		return min(smallest, judgeCoresAlone)
+	}
+	cores := judgeCores
+	if len(cpus) == 1 && smallest > 0 && replicas*cores > smallest {
+		cores = max(1, smallest/replicas)
+	}
+	return cores
+}

internal/cli/judgekeeper_test.go

@@ -1,6 +1,7 @@
 package cli
 
 import (
+	"context"
 	"errors"
 	"log/slog"
 	"slices"
@@ -124,3 +125,81 @@ func TestCategoriesFollowTheJudges(t *testing.T) {
 		t.Errorf("no categories (every one counts) became %v", got)
 	}
 }
+
+type fakeProfiles struct {
+	set map[string][]catalog.Profile
+}
+
+func (f *fakeProfiles) SetProfiles(_ context.Context, name string, ps []catalog.Profile, _ string) (catalog.Model, error) {
+	if f.set == nil {
+		f.set = map[string][]catalog.Profile{}
+	}
+	f.set[name] = ps
+	return catalog.Model{Name: name, Profiles: ps}, nil
+}
+
+// A judge that v0.14.6 or earlier's init installed is moved to today's
+// figures, once, and its replicas restarted onto them; one somebody changed
+// is left alone.
+func TestAnEarlierInstallsJudgeIsRefittedOnce(t *testing.T) {
+	lib := guard.Config{Policies: map[string]guard.Policy{
+		"baseline": {Judge: &guard.JudgePolicy{Model: "qwen3guard-0.6b", Input: "block"}},
+	}}
+	earlier := guardModel("http://10.0.0.5:8081/qwen3guard-0.6b/guard/g.gguf", 2, 1)
+	earlier.Profiles[0].MinMemoryGB, earlier.Profiles[0].Args = 4, []string{"--ctx-size", "8192"}
+	inCatalog := []catalog.Model{earlier}
+	fp := &fakeProfiles{}
+	var restarted []string
+	k := &judgeKeeper{
+		library:  func() guard.Config { return lib },
+		models:   func() []catalog.Model { return inCatalog },
+		serve:    &fakeServe{},
+		log:      slog.New(slog.DiscardHandler),
+		profiles: fp,
+		restart:  func(ids ...string) error { restarted = append(restarted, ids...); return nil },
+		replicas: func(string) []string { return []string{"j-1", "j-2"} },
+		nodeCPUs: func() []int { return []int{4} },
+	}
+	k.check()
+	got := fp.set["qwen3guard-0.6b"]
+	if len(got) != 1 || got[0].MinMemoryGB != 2 || got[0].CPUCores != 2 || !slices.Contains(got[0].Args, "--cache-ram") {
+		t.Fatalf("refitted to %+v", got)
+	}
+	if !slices.Equal(restarted, []string{"j-1", "j-2"}) {
+		t.Errorf("restarted %v", restarted)
+	}
+	k.check()
+	if len(restarted) != 2 {
+		t.Error("refitted twice")
+	}
+
+	// Changed by somebody: an extra arg. Left as it is.
+	mine := guardModel("http://x/g.gguf", 2, 3)
+	mine.Profiles[0].Args = []string{"--ctx-size", "16384"}
+	inCatalog = []catalog.Model{mine}
+	fp.set, k.looked = nil, nil
+	k.check()
+	if fp.set != nil {
+		t.Errorf("a judge set by hand was changed: %+v", fp.set)
+	}
+}
+
+func TestAJudgeIsRefittedToTheCoresInitWouldGive(t *testing.T) {
+	for _, c := range []struct {
+		replicas int
+		cpus     []int
+		want     int
+	}{
+		{1, []int{4}, 4},
+		{1, []int{2}, 2},
+		{1, []int{16}, 4},
+		{2, []int{4}, 2},
+		{2, []int{2}, 1},
+		{2, []int{4, 32}, 2},
+		{2, nil, 2},
+	} {
+		if got := refitCores(c.replicas, c.cpus); got != c.want {
+			t.Errorf("%d judges on %v: %d cores, want %d", c.replicas, c.cpus, got, c.want)
+		}
+	}
+}

internal/cli/server.go

@@ -593,6 +593,25 @@ func newServerCmd() *cobra.Command {
 							},
 							gpus: func() []adminapi.ClassUse { return adminAPI.Summary().GPUs },
 							log:  log,
+							// An earlier install's judge, moved to today's figures.
+							profiles: catalogSvc,
+							restart:  admin.Reconciler().Restart,
+							replicas: func(model string) []string {
+								var ids []string
+								for _, r := range admin.Reconciler().ReadyReplicas() {
+									if r.Model == model {
+										ids = append(ids, r.ID)
+									}
+								}
+								return ids
+							},
+							nodeCPUs: func() []int {
+								var out []int
+								for _, n := range admin.Nodes() {
+									out = append(out, n.CPUCount)
+								}
+								return out
+							},
 						}
 						go keeper.run(ctx, 30*time.Second)
 					}

internal/control/modelsvc/modelsvc.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 	"log/slog"
+	"slices"
 	"sync"
 	"time"
 
@@ -248,6 +249,19 @@ func (s *Service) Resources(ctx context.Context, name, profile string, memoryGB,
 	return final, err
 }
 
+// SetProfiles replaces a model's profiles, as a model added with them
+// would have: for a model whose engines are to run otherwise, its args among
+// it. Running replicas keep what they were started with until restarted.
+func (s *Service) SetProfiles(ctx context.Context, name string, profiles []catalog.Profile, by string) (catalog.Model, error) {
+	if len(profiles) == 0 {
+		return catalog.Model{}, errors.New("a model needs a profile")
+	}
+	return s.update(ctx, name, by, "replace its profiles", func(m *catalog.Model) error {
+		m.Profiles = slices.Clone(profiles)
+		return nil
+	})
+}
+
 // SetClass sets a model's capacity class: critical, standard or
 // opportunistic, or empty to go back to what its scaling implies.
 func (s *Service) SetClass(ctx context.Context, name, class, by string) (catalog.Model, error) {