Commit Graph

3 Commits

Author SHA1 Message Date
Luke Tornquist
506a588f88 refactor(relay): remove database usage-metric queries (#9040)
## Summary

The relay no longer runs database aggregate queries to emit usage
gauges. Fleet and per-community counts of users, channels, relay
members, workflows, git repos, communities, messages, and active
users/channels are no longer relay metrics, and neither are the snapshot
health gauges that came with them.

### Removed

- **Gauges:** `buzz_total_users`, `buzz_total_channels`,
`buzz_total_relay_members`, `buzz_total_workflows`,
`buzz_total_git_repos`, `buzz_total_active_users`,
`buzz_total_messages`, `buzz_total_active_channels`,
`buzz_communities_estimated` / `buzz_communities_total`, and every
DB-derived `buzz_community_*` series (users, channels, messages, relay
members, workflows, git repos, active users, active channels).
- **Per-community mode:** `BUZZ_USAGE_METRICS_PER_COMMUNITY=all` and
everything it fed: the per-community in-memory gauges,
`buzz_community_storage_bytes` / `buzz_community_storage_objects`,
`buzz_storage_unmapped_community_bytes`, the community → host map query,
and the emission-scope bookkeeping that cleared series for renamed or
removed communities. No deployment set it. If one still does, the relay
ignores it.
- **Health signals:** `buzz_usage_snapshot_available`,
`buzz_usage_snapshot_age_seconds`, `buzz_usage_query_skipped_total`, and
the `usage_fleet_*` paths of `buzz_db_route_decision`.
- **Code and config:**
  - `buzz-db/src/store/usage.rs`, including its aggregate queries.
- The relay's `FleetUsageSchedule` and its cadence/deadline/retry
machinery.
  - The replica-only telemetry route (`Db::route_usage_read`).
- `BUZZ_USAGE_METRICS_REPLICA_MAX_AGE_MS` and
`DbConfig::usage_metrics_replica_max_age_ms`. If a deployment still sets
the env var, the relay now ignores it; startup doesn't fail.
- **Reader maintenance pool operation:** `ReaderOperation::Maintenance`
and its `close_on_drop` release path existed only for those telemetry
reads, so they're removed too. The pool-acquire contract drops from
twelve to eleven valid pairs, which lowers the per-pod series ceiling
from 216 to 198.
- **Dead code:** `Db::active_community_hosts` had no callers.

### Kept

- **Leader:** the usage poller's leader lock, plus the leader's invite
reaping and fleet storage-snapshot gauges. The session advisory lock
(`SessionLeader`, `Db::try_lock_session_leader`) moves to
`buzz-db/src/store/leader_lock.rs`, since storage-usage delivery uses it
too and it has nothing to do with usage queries.
- **In-memory gauges:** pod-local connection, subscription, and
online-user gauges. They read process state, not the database.
- **Writer maintenance pool operation:** `WriterOperation::Maintenance`
stays. Dozens of writer-side maintenance paths across `buzz-db` use it
(reapers, retention, the leader lock). The reader variant only ever
served the telemetry reads.
- **Storage-usage delivery:** unchanged. It reads the storage snapshot
for billing, not for metrics.

`docs/usage-metrics.md`, `docs/storage-accounting.md`, `.env.example`,
and the Helm chart README are updated to match.

## What got simpler

This is net deletion (~3.6k lines). One telemetry subsystem is gone: two
collection families with independent cadences, availability and age
semantics, relay-side deadlines, a dedicated replica routing policy, two
config knobs, a per-community emission mode, and a pool-operation
variant. Leader election now does only leader work, and it lives in its
own module.

## Operational note

Dashboards and monitors that read the removed series will go to no data
once this rolls out.

## Testing

- `cargo fmt --check`, workspace `cargo clippy --all-targets -D
warnings`.
- `buzz-db` lib, `observability_source`, and doc tests.
- `buzz-relay` lib tests.
- The Postgres lane for `buzz-db` (lib + tests) and `buzz-relay` (lib).

All of these run on a remote workstation at the PR head.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Signed-off-by: Luke Tornquist <tornquist@squareup.com>
Co-authored-by: Elrond <28d6302a099e5225b02c4155ac4236e4912603df2ab08dbfc2f4fef08ce598c8@buzz.block.builderlab.xyz>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-11-04 22:00:30 -05:00
Shu Hui
fa7a3bfbda feat(relay): push per-community storage usage to kgoose (#8714)
### Why?
To bill hosted communities for storage in Orb, kgoose needs
per-community storage usage. The relay already computes it in a daily
snapshot, but nothing delivered it anywhere.

## Summary
- Adds opt-in `BUZZ_STORAGE_USAGE_URL`. When it is set, one
leader-elected relay pod checks every 5 minutes for a new storage
snapshot and POSTs it to kgoose's `POST /v1/buzz/storage-usage/record`
(squareup/cash-server#144285) in consecutive batches of up to 50
communities until every community is sent.
- Each batch is `{measured_at, communities: [{community_host,
storage_bytes, storage_objects}]}`. Active communities with no stored
bytes are reported as zero, and re-sends are safe because kgoose bills
each community once per UTC day.
- Retries on 408, 429, 5xx, and transport errors. No migration;
documented in `docs/storage-accounting.md`. kgoose authenticates the
relay as the `buzz` mesh service, so the relay needs mesh egress to
kgoose-builderbot.

### Related issue
None found. Complements #7899 (snapshot history in the DB). Receiving
endpoint: squareup/cash-server#144285.

### Testing
Unit tests cover batching, retry and reject handling, zero-filling, and
a real HTTP delivery that checks the exact kgoose request body. A
Postgres-gated DB test covers the new reads. End to end, a local relay
delivered to a fake endpoint once per new snapshot.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Signed-off-by: Shu Hui <shu@squareup.com>
Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-11-04 09:40:06 +11:00
ravarora2
4142d2b84e Use worker snapshots for relay storage metrics (#7845)
## Summary

Make the relay read completed storage-accounting snapshots from
PostgreSQL by default. An environment with no snapshot emits no storage
metrics. When a worker publishes its first result, the relay picks it up
on the next successful leader usage tick, without a restart or
configuration change.

This changes how storage usage is measured and reported. **S3 remains
the object store. PostgreSQL stores the completed counts, byte totals,
community breakdown, and calculation metadata—not the objects
themselves.**

### Why move relay storage accounting entirely to database reads?

Today the relay supports two sources: its own S3 scan (`inline`, the
default) and the worker's saved snapshot (`external`). That requires
operators to deploy a worker and then coordinate a separate relay-mode
change in each environment.

The worker already owns the S3 listing and calculation. It runs in a
separate process with its own object cap, memory limit, and deadline.
Keeping a second scan inside the serving relay retains the resource
pressure and failure modes that this isolation is meant to remove.

PostgreSQL provides a durable handoff. The worker replaces one completed
snapshot atomically after a successful calculation. The relay reads that
row and exposes its values through the existing metrics endpoint. A
relay restart or leadership change can load the last completed result
without scanning the bucket again.

There is deliberately no S3 fallback when a snapshot is absent or a read
fails. Such a fallback would put the expensive scan back in the relay
precisely when a worker is absent or unhealthy. It would also leave two
calculation paths with different resource limits and freshness behavior.

### What happens if no worker exists?

**A worker that has never published is a normal, successful inactive
state.** The snapshot table must exist through the normal database
schema, but it may contain zero rows. The reader returns success, emits
no storage totals or failed-load gauge, and checks again on the next
usage tick. It does not exit the relay, start a worker, or list S3.

The relay checks for a completed database row; it does not inspect
Kubernetes Jobs or CronJobs. Worker presence and snapshot presence are
therefore different:

| Situation | Storage-reader behavior |
|---|---|
| No worker and no snapshot row | Return success, emit no storage
metrics, and query again next tick. |
| Worker starts later and publishes its first row | Read and emit it on
the next successful leader usage tick; no restart or mode change. |
| Worker is removed or fails, but its last valid row remains | Continue
reporting the last completed totals with their increasing age. |
| Query succeeds but a previously present row has been removed | Clear
the cache and stop refreshing storage series; existing exporter series
expire through the idle timeout. |
| Database read fails, times out, or returns an invalid snapshot | Log a
warning, set `buzz_storage_snapshot_load_ok=0`, retain any last-good
cached totals, and retry next tick. |
| Snapshot table is missing | Treat this as a schema error, not normal
worker absence; follow the failed-read behavior above. |
| `BUZZ_STORAGE_METRICS=off` | Skip the snapshot query and all storage
metric emission. |

No row means “not measured,” not zero bytes. A valid completed snapshot
of an empty bucket can report zero. If a read fails before any good
snapshot has been cached, only failed-load health is emitted.

These reads happen in the existing background metrics task, not the
relay startup path. A storage-read failure does not request process exit
or change readiness directly. A wider database outage can still affect
the relay's existing database-dependent operations and readiness.

### Read, parse, and emit path

```text
Worker: S3 listing -> BucketSnapshot -> JSON -> PostgreSQL
Relay: PostgreSQL -> JSON -> BucketSnapshot -> existing metric gauges
Collector: relay /metrics endpoint -> Datadog
```

1. `main.rs::run_storage_sweep_tick` calls the reader from the existing
leader-only usage task. The default interval remains 300 seconds.
2. `storage_sweep.rs::run_storage_metrics_tick` coordinates the read,
cache update, failure health, and metric emission.
3. `refresh_persisted_snapshot` calls the existing
`Db::load_storage_accounting_snapshot()` method. A five-second timeout
covers pool acquisition and the query. It uses the relay's existing
pool.
4. The existing query in `buzz-db/src/store/storage_accounting.rs` reads
`snapshot`, `completed_at`, `duration_ms`, `max_objects`, and `code_sha`
from the singleton row.
5. `serde_json::from_value(stored.snapshot)` decodes the JSON into the
existing `buzz_media::BucketSnapshot` type. Rust infers that type from
`cache_persisted_snapshot`'s argument. The generated `Deserialize`
implementation handles all fields, including the UUID-keyed
`per_community` map.
6. `emit_cached_storage_metrics` sets the existing physical/logical
totals and community byte/object gauges. The existing Prometheus
exporter exposes them for Datadog collection; this code does not send
snapshot JSON to Datadog.

The worker's `BucketSnapshot`/`CommunityStorage` structures, JSON field
names, SQL publication method, and database schema are unchanged. The
old external-mode JSON conversion moves out of `main.rs` into the reader
helper. No new format or hand-written field parser is needed. Duration
and object-cap metadata are validated before replacing the cache.

The five-second relay read timeout is separate from the worker's
30-second startup acquisition budget introduced in #7770. This PR does
not change the worker's pool or startup logic.

### Configuration and code changes

| Configuration | Before | After |
|---|---|---|
| Unset, `inline`, or `on` | Relay-local S3 scan | Read completed
database snapshots. `inline` logs one migration warning. |
| `external` or `snapshot` | Read completed database snapshots |
Continue reading snapshots. |
| `off` | Disabled | Disabled. |
| Unknown or empty value | Disabled with a configuration error | Same. |

Existing `inline` settings intentionally become reader aliases. Merely
changing the default would leave older deployments on their explicit
`inline` setting and preserve the need for coordinated configuration
PRs.

Remove relay-local scan scheduling, in-flight scan state, scan
configuration, and obsolete scan-attempt tests and health metrics.
Preserve the physical/logical total and per-community metric names,
leader-only emission, community scope filtering, and cleanup of old
community labels.

The shared relay-state field remains in place; its comment now describes
a cached worker result. The Helm chart defaults to `relayMode: external`
while leaving `storageAccounting.enabled: false`. Its rendering test
verifies that the reader is configured even when no worker is created.
The reader regression tests cover missing rows, later publication,
updates, invalid data, timeout, removal, reactivation, and the explicit
off switch. `docs/storage-accounting.md` describes this operating model.

### Freshness and rollout impact

`buzz_storage_snapshot_age_seconds` uses the worker's original
completion timestamp. Re-reading an old row never makes it fresh.
`buzz_storage_snapshot_load_ok=1` means the row was read and decoded; it
does not prove that the worker's latest attempt succeeded.

Monitor snapshot age against the worker's schedule and allowed runtime,
and monitor Job failures separately. The old relay scan-attempt health
gauges are retired because the relay no longer runs those scans.

Deploy this relay version through the usual release process. Once it
reaches an environment, workers can be enabled independently.
Already-released charts that still set `inline` work with the new
binary; future chart releases default explicitly to `external`. An
intentional `off` override still requires an operator to enable the
reader.

**Environments with no completed snapshot lose relay-calculated storage
totals after this upgrade.** That is the intended tradeoff for removing
scans from the serving process. Environments with a prior snapshot
continue showing its last completed totals and age. This PR does not
install workers in additional environments or deploy the new relay
image.

### Related issue

Related to #4601. Follows the worker startup fix in #7770. The separate
fleet-usage collector work in #7176 overlaps this code and may need
reconciliation when it merges.

### Testing

Built and ran the relay locally against isolated PostgreSQL and Redis
with the legacy `inline` setting, five-second usage ticks, and a
15-second metric idle timeout. The same process was exercised through
these steps:

1. Start with an empty snapshot table: relay becomes ready and exposes
no storage series.
2. Publish a snapshot containing 123 bytes: the community gauge becomes
123.
3. Replace it with 456 bytes: the gauge becomes 456.
4. Remove the row: storage series expire without fabricating a zero-byte
measurement.
5. Publish 789 bytes: metrics reactivate without restarting the relay;
readiness remains healthy.

The local S3 endpoint recorded zero requests. The unrelated Git
conformance startup probe was disabled for this isolated reader check;
the test covers storage accounting, not every other use of S3 in the
relay. No new relay image was deployed to staging or production during
this test.

The broad local integration run also hit an existing
`p0_pool_acquisitions_use_typed_operation_pairs_without_other` failure
in `buzz-db/tests/observability_source.rs`. The same source-only test
fails on unmodified `main` at `0ef7a2222`; this PR changes neither the
test nor its failing source.

The full local `just ci` run stopped at mobile native-asset setup: the
`objective_c` build hook received no SDK path from `xcrun`. Mobile tests
did not run.

Generated with Codex

Signed-off-by: Ravneet Arora <rarora@squareup.com>
2026-09-23 14:39:39 -04:00