omnigraph/docs/user/cluster-config.md

Cluster Config

Status: Phase 5 — cluster-booted serving (omnigraph-server --cluster).

New to the cluster tooling? Start with the operator how-to guide, cluster.md — this document is the reference.

Cluster config is the future control-plane configuration surface for a whole OmniGraph deployment. In this stage, OmniGraph can validate a local cluster.yaml folder, produce a deterministic read-only plan, inspect the local JSON state ledger, explicitly refresh/import graph observations into that ledger, manually remove a held local state lock by exact lock id, and apply the executable subset of the plan — stored-query and policy-bundle catalog writes, graph creation (a declared graph that does not exist yet is initialized by apply at the derived root), schema updates (soft drops only), and — behind an explicit, digest-bound approval — graph deletion. It does not perform data-loss schema migrations, start servers, or serve anything it applies: the server still boots from omnigraph.yaml.

Commands

omnigraph cluster validate --config ./company-brain
omnigraph cluster plan     --config ./company-brain --json
omnigraph cluster apply    --config ./company-brain --json
omnigraph cluster approve  graph.<id> --config ./company-brain --as <actor>
omnigraph cluster status   --config ./company-brain --json
omnigraph cluster refresh  --config ./company-brain --json
omnigraph cluster import   --config ./company-brain --json
omnigraph cluster force-unlock <LOCK_ID> --config ./company-brain --json

--config points at a directory, not a file. The directory must contain cluster.yaml. When omitted, it defaults to the current directory.

Relationship to omnigraph.yaml

cluster.yaml does not replace omnigraph.yaml, and the two never describe the same fact. omnigraph.yaml remains how the CLI and server are configured today (graph targets, server bind, CLI defaults, credential env references) and is its long-term home for per-operator settings. cluster.yaml is the shared desired state of a whole deployment, read only by the cluster commands via --config. In the current stage, nothing recorded in the cluster state ledger affects what a server serves or what other CLI commands target — the cluster catalog is inspectable, not live. When server boot from cluster state ships in a later stage, it will be an explicit per-deployment mode switch, not a merge of the two files.

Supported cluster.yaml

Stage 3A accepts only this resource subset:

version: 1
metadata:
  name: company-brain

state:
  backend: cluster
  lock: true

graphs:
  knowledge:
    schema: ./knowledge.pg
    queries:
      find_experts:
        file: ./knowledge.gq

policies:
  base:
    file: ./base.policy.yaml
    applies_to: [knowledge]

metadata.name is a display label. state.backend may be omitted or set to cluster; external state backends are reserved for a later stage. state.lock defaults to true. When enabled, cluster plan, cluster apply, cluster refresh, and cluster import briefly acquire <config-dir>/__cluster/lock.json, then remove it before returning. cluster status never acquires the lock; it only reports whether one is present. cluster force-unlock is the only lock-removal command; it requires the exact lock id and should be run only after confirming no cluster operation is active.

Validation

cluster validate checks:

• cluster.yaml syntax and supported fields
• duplicate YAML keys
• schema, query, and policy file existence
• schema parsing and catalog construction
• stored-query parsing and query-name matching
• stored-query type-checking against the desired schema
• policy applies_to graph references

Fields reserved for later phases, such as pipelines, embeddings, ui, aliases, and bindings, fail with a typed diagnostic instead of being silently ignored.

Planning

cluster plan first performs validation, then reads local JSON state from:

<config-dir>/__cluster/state.json

If the file is missing, the state is treated as empty and every desired resource is planned as a create. If present, the file must use this shape:

{
  "version": 1,
  "state_revision": 0,
  "applied_revision": {
    "config_digest": "...",
    "resources": {
      "graph.knowledge": { "digest": "..." },
      "schema.knowledge": { "digest": "..." },
      "query.knowledge.find_experts": { "digest": "..." },
      "policy.base": {
        "digest": "...",
        "applies_to": ["cluster", "graph.knowledge"]
      }
    }
  },
  "resource_statuses": {
    "graph.knowledge": {
      "status": "applied",
      "conditions": [],
      "message": "optional status detail"
    }
  },
  "approval_records": {},
  "recovery_records": {},
  "observations": {}
}

state_revision, resource_statuses, approval_records, recovery_records, and observations are optional so older Stage 1 state fixtures keep working. Missing state_revision is treated as 0. Resource status values are pending, planned, applying, applied, drifted, blocked, or error.

Plan output compares desired resource digests against state resource digests and reports create, update, and delete changes. It also reports the state CAS (sha256:<digest>) and state revision. state_observations.locked means an existing lock file was observed, along with its metadata (lock_id, lock_operation, lock_created_at, lock_pid, lock_age_seconds); a successful plan instead reports lock_acquired: true and an acquired_lock_id, then releases the lock before returning. The command never writes state.json and does not scan live graphs. Use explicit cluster refresh / cluster import when the state ledger should be updated from live observations. Live drift scans during plan are later-stage work.

Policy entries additionally record their applied applies_to bindings as normalized typed refs — the state ledger is serving-sufficient for the future server-boot stage. A change to applies_to alone (the policy file digest unchanged) appears in the plan as an Update marked binding_change (human output: [bindings]), applies like any catalog change, and counts toward convergence; ledgers written before this field existed are backfilled by the next apply.

Each plan change carries a disposition field — an honest preview of what cluster apply will do with it in this stage: applied (executes), derived (a graph.<id> composite-digest update that converges automatically once its query digests land), deferred (graph/schema change, later phase), or blocked (query/policy gated by an unapplied or missing dependency, with the condition in reason).

Apply

cluster apply executes the executable subset of the plan — stored-query and policy-bundle changes, graph creates, and schema updates. There is no confirm flag: cluster plan is the preview, and apply recomputes the same diff under the state lock before executing, so a stale preview can never be applied. Apply requires an existing state.json (state_missing directs you to cluster import first).

For each applied create/update, the resource payload is written content-addressed into the local catalog:

<config-dir>/__cluster/resources/query/<graph>/<name>/<digest>.gq
<config-dir>/__cluster/resources/policy/<name>/<digest>.yaml

Extensions are fixed per kind regardless of the source file's name. Payloads are written before the state update because state.json is the publish point: if the final CAS-checked state write fails, no success is reported and the digest-named blobs already written are inert — re-running apply is the repair. Deletes remove the resource from state; their old payload blobs stay on disk (garbage collection is a later stage). Re-running a converged apply is a no-op: no state write, no revision change (state_written: false).

Applied means serving — for deployments that opt in. A server started with --cluster <dir> boots from the applied revision (see Serving from the cluster); it picks up newly applied state on its next restart. Deployments still booting from omnigraph.yaml are untouched: for them, applied means recorded in the catalog, nothing more.

Graph creation

A graph.<id> create (the graph is declared but no root exists) is executed by apply: the graph is initialized at the derived root

<config-dir>/graphs/<graph-id>.omni

with the declared schema, before any catalog writes, so queries and policies that depend on the new graph apply in the same run. Each create is fenced by a recovery sidecar under __cluster/recoveries/{ulid}.json, written before the init and removed only after the state update lands. If apply crashes in between, the next state-mutating command (apply, refresh, import) runs a recovery sweep that classifies the survivor by observation: an absent root removes the stale intent; a completed create rolls the cluster state forward (recorded in the state's recovery_records); a partial root reports graph_create_incomplete (status error — remove the root and re-run apply; nothing is auto-deleted); unexpected graph content reports actual_applied_state_pending (status drifted — run cluster refresh and re-plan). While a kept sidecar is pending, that graph's create and its dependents are blocked with cluster_recovery_pending. Read-only commands (status, plan) warn about pending sidecars without acting on them.

Re-creation is convergence. If a graph root disappears out-of-band, refresh records the drift and the next plan proposes a create — and apply will execute it, producing an empty graph at the root. The data was already lost when the root vanished; the create is visible in the plan (disposition applied) before anything runs.

Schema updates

A schema.<id> update (the declared schema differs from what state records) is executed by apply via the engine's schema-apply, after graph creates and before catalog writes — so a query change that depends on the new schema applies in the same run. Each schema apply is sidecar-fenced like a create: pre-operation manifest version recorded, post-operation version written back, sidecar retired only after the state update lands; the recovery sweep classifies survivors by schema digest (consistent ledger → retired; completed on the graph → state rolled forward with an audit entry; anything else → drifted/actual_applied_state_pending, kept).

Migrations run with soft drops only — a removed property disappears from the current version while prior versions retain the data (reversible until cleanup). Data-loss migrations (allow_data_loss) are not reachable from cluster apply until the approval-artifact stage. Unsupported migrations (e.g. changing a property's type), engine lock contention, or graphs with user branches fail loudly as schema_apply_failed with the engine's message; dependent changes are demoted to blocked and graph-moving work stops for the run.

cluster plan previews schema updates with the engine's real migration plan: each schema change carries a migration field (supported + typed steps), and the human output prints the steps. If the live graph cannot be opened the preview degrades to the digest diff with a schema_preview_unavailable warning.

Drift is converged, not just reported. A schema changed out-of-band on the live graph shows up as drifted after refresh, and the next plan proposes migrating it back to the declared schema — apply executes that like any other soft migration. Drift correction is gated by the same rules as any change; nothing about it is hidden (the plan shows the steps, including soft drops of out-of-band fields).

Attribution. cluster apply --as <actor> records the operator identity in recovery sidecars and audit entries and threads it to the engine's schema-apply (so commit attribution and Cedar enforcement — wherever a policy checker is installed — work unchanged).

Approvals and graph deletion

Deleting a graph is the irreversible tier: it requires a recorded human decision. cluster plan lists the gate under approvals_required (one gate per graph — the graph-level approval carries its schema and queries); cluster approve graph.<id> --as <actor> writes a digest-bound artifact to

<config-dir>/__cluster/approvals/<approval-id>.json

bound to the exact desired config digest and the change's state digest, so any config or state drift after approving invalidates the artifact automatically (approval_stale warning; it never authorizes a different change). An unapproved delete blocks with approval_required.

An approved delete executes last in the apply run: the graph root is removed recursively, the subtree (graph, schema, its queries) is tombstoned out of the state ledger with a tombstone observation, and the approval is consumed — recorded in the state's approval_records in the same state update, and the artifact file rewritten with consumed_at (the file is never deleted: the audit fact survives the loss of either store). A failed run consumes nothing; the approval stays valid for the retry. Catalog blobs of the deleted graph's queries stay on disk (GC is a later stage).

Crash recovery for deletes: a completed-but-unrecorded delete is rolled forward by the sweep (tombstone + approval consumption + audit entry); an incomplete delete (root still present) is retired with a graph_delete_incomplete warning and simply re-proposed — prefix removal is idempotent, so the still-approved retry is the repair.

Standalone schema deletes are never executed by this stage. They are reported as deferred (warning apply_unsupported_change), and query/policy changes that depend on them are blocked (warning apply_dependency_blocked, status blocked in state). A partially-applicable plan still exits 0 with warnings; the JSON converged field is the automation signal for "state now matches the desired revision". The applied config_digest is only recorded when apply fully converges. The graph.<id> composite digest is recomputed from state's own schema/query digests after each apply, so applied query changes converge without graph movement.

Serving from the cluster (the mode switch)

omnigraph-server --cluster ./company-brain --bind 0.0.0.0:8080

--cluster <dir> is an exclusive boot source (axiom 15): it cannot combine with a graph URI, --target, or --config, and in this mode omnigraph.yaml is never read — not for graphs, not for queries, not for policies. The server serves the applied revision: graph roots recorded in state.json, stored-query and policy content from the content-addressed catalog at the applied digests (re-verified at boot), and policy bundles wired by their applied applies_to bindings — cluster-bound bundles become the server-level Cedar engine, graph-bound bundles attach per graph. Un-applied config drift never leaks into serving; cluster plan is where drift is visible. Routing is always multi-graph (/graphs/{id}/...). Bearer tokens and the bind address stay process-level (flags/env) — they are per-replica facts, not cluster facts.

Boot is fail-fast: missing or unreadable state, pending recovery sidecars, missing/tampered catalog blobs, policy entries without binding metadata (pre-binding ledgers — re-run cluster apply), an empty graph set, more than one policy bundle binding a single scope (split or merge bundles; stacked scopes are a later stage), unopenable graph roots, and stored queries that no longer type-check all refuse startup with a remedy. A held state lock is not an error — boot reads the atomically-replaced state file without locking.

Serving is static per process: the server reads the applied revision once at startup, so picking up newly applied state means restarting it. Stored queries are all listed in GET /queries in cluster mode (the cluster registry has no expose flag; exposure becomes a policy decision in a later phase).

Status

cluster status reads the same local JSON state ledger and prints what the ledger says is deployed. It does not validate referenced schema/query/policy files and does not inspect live graphs. Missing state.json succeeds with a warning; invalid state JSON or an unsupported state version fails. If a lock is present, status reports its id, operation, creation time, pid, and age.

Status also verifies the catalog payloads read-only: every query/policy digest recorded in state is checked against its content-addressed blob under __cluster/resources/ (existence and full digest re-hash). A missing or mismatched blob is reported as a warning (catalog_payload_missing / catalog_payload_mismatch); an unreadable blob is an error (catalog_payload_read_error) because an unverifiable catalog must not report healthy. Status never writes state — persisting the drifted condition is refresh's job. The check runs without the state lock, so it is a point-in-time report.

Refresh And Import

cluster refresh updates an existing state.json from actual observations. cluster import creates the first state.json when the ledger is missing. Both commands open declared graphs read-only at:

<config-dir>/graphs/<graph-id>.omni

They observe only branch main, recording graph existence, manifest version, live schema digest, desired schema digest, and schema-match status under observations["graph.<id>"]. Missing graph roots are recorded as drift and remove the graph/schema digests from state so a later plan proposes creates. Invalid graph roots are recorded as errors; refresh persists the error observation and exits non-zero, while import exits non-zero without creating initial state.

Refresh also verifies the catalog payloads of every query/policy digest recorded in state (the same check cluster status reports read-only), and closes the loop:

• a missing or digest-mismatched blob marks the resource drifted (condition payload_missing / payload_mismatch) and removes its digest from state — so the next cluster plan proposes a create and the next cluster apply republishes the blob (the self-heal loop, mirroring how a missing graph root is handled);
• an unreadable blob (IO error other than not-found) keeps the digest, marks the resource error (condition payload_read_error), and exits non-zero — transient IO must not trigger a spurious republish.

Upgrade note: a state ledger written before catalog publish existed records query/policy digests with no blobs on disk; the first refresh after upgrading flags them all payload_missing, and a single cluster apply republishes everything and converges.

Refresh/import do not observe query or policy resources beyond their catalog payloads yet. Existing query and policy state digests are preserved on refresh (unless their payload drifted, above) and are not invented on import.

Force Unlock

cluster force-unlock <LOCK_ID> removes <config-dir>/__cluster/lock.json only when the file exists, is valid version-1 lock JSON, and its lock_id exactly matches the argument. A wrong id, missing lock, invalid lock JSON, or unsupported lock version exits non-zero and leaves the file untouched.

This is manual recovery for abandoned local locks. OmniGraph does not perform PID-liveness checks, TTL expiry, stale-lock breaking, or automatic unlock in Stage 2C.