mirror of
https://github.com/agent-substrate/substrate.git
synced 2026-11-11 10:23:17 +08:00
### Description This PR introduces native, secure support for using Cloud SQL as the PostgreSQL store backend for `ate-api-server`. To ensure the highest level of security and ease of use in GCP environments, this integration leverages the Cloud SQL Auth Proxy sidecar with automatic IAM database authentication. This means transport security (TLS 1.3 tunnel) is handled automatically, and database sessions are authenticated using Workload Identity via short-lived OAuth tokens, completely eliminating the need for database passwords. ### Key Changes * **Cloud SQL Auth Proxy Sidecar:** Added `manifests/ate-install/cloudsql-proxy-patch.yaml` to patch the sidecar into the `ate-api-server` deployment when a Cloud SQL instance is configured. * **Automated Provisioning:** Extended `tools/setup-gcp` with a new `cloudsql` command. This handles the idempotent creation of the Cloud SQL instance, Google Service Accounts (GSA), IAM bindings, and Workload Identity bindings. * **Installation Script Updates:** Updated `hack/install-ate.sh` to parse new environment variables (e.g., `ATE_API_POSTGRES_CLOUDSQL_INSTANCE`, `ATE_API_POSTGRES_CLOUDSQL_GSA`) and correctly synthesize the passwordless DSN and ConfigMaps for the proxy. * **Security & Documentation:** * Added extensive documentation in `tools/setup-gcp/cloud-sql.md` covering provisioning, schema privileges, deployment, and database scaling. * Updated `docs/threat-model.md` to reflect the new Cloud SQL egress flows and Auth Proxy tunnel mechanics. * **Dependencies:** Vendored required Google API clients (`sqladmin/v1`, `servicenetworking/v1`, `iam/v1`) for the GCP setup tool. - [X] Tests pass - [X] Appropriate changes to documentation are included in the PR
96 lines
4.5 KiB
Markdown
96 lines
4.5 KiB
Markdown
# Scaling the Cloud SQL store
|
||
|
||
Sizing guidance for running the ateapi PostgreSQL store
|
||
([tools/setup-gcp/cloud-sql.md](../../tools/setup-gcp/cloud-sql.md)) at large
|
||
actor counts and high request rates.
|
||
|
||
The provisioning defaults (`db-custom-2-8192`, 10 GB disk) suit development
|
||
and modest fleets. At large actor counts the store becomes I/O-bound: once
|
||
tables and indexes outgrow memory, uniform random reads fall out of cache and
|
||
point lookups pay persistent-disk latency (several milliseconds) instead of
|
||
microseconds. The knobs below address that, in order of leverage.
|
||
|
||
## Instance shape
|
||
|
||
Set with `--tier` / `--edition` at create time, or `gcloud sql instances
|
||
patch` later — edition/tier changes restart the instance.
|
||
|
||
- Memory is the primary lever: reads are served from cache until the working
|
||
set (tables + indexes) outgrows RAM, then p50 degrades to disk latency.
|
||
- Once the dataset can't fit RAM on any tier, switch to
|
||
[`--edition=enterprise-plus`](https://docs.cloud.google.com/sql/docs/postgres/editions-intro)
|
||
with `--tier=db-perf-optimized-N-<vCPU>`. The tool
|
||
enables its **local-SSD data cache**, which extends the effective cache
|
||
several times beyond RAM: reads that would miss to persistent disk are
|
||
served from local SSD at a fraction of the latency.
|
||
|
||
## Storage
|
||
|
||
Set with `--storage-size` at create time; it only grows afterwards.
|
||
|
||
- Persistent-disk IOPS and throughput scale with provisioned size — the disk
|
||
is also the I/O knob. Pre-size to ~2× the expected dataset (records +
|
||
indexes + WAL + bloat) rather than relying on auto-resize, which grows in
|
||
small steps and stalls under bulk loads.
|
||
|
||
## Connection sizing for a target throughput
|
||
|
||
Set with `ATE_API_POSTGRES_POOL_MAX_CONNS` at deploy time. Target connections
|
||
equal throughput multiplied by average query latency:
|
||
|
||
```
|
||
connections ≈ QPS × mean latency in seconds
|
||
≈ 10,000 req/s × 0.006 s ≈ 60 active connections
|
||
```
|
||
|
||
Provision ~2× headroom for bursts (e.g. 4 replicas × `ATE_API_POSTGRES_POOL_MAX_CONNS=32`).
|
||
An undersized pool causes client-side queuing inside `pgx` rather than database errors.
|
||
Ensure total connections across all replicas stay within Cloud SQL's limit:
|
||
|
||
```
|
||
replicas × pool_max_conns ≤ max_connections − slack (superuser, maintenance)
|
||
```
|
||
|
||
Exceeding
|
||
[`max_connections`](https://docs.cloud.google.com/sql/docs/postgres/quotas#maximum_concurrent_connections)
|
||
does error (`FATAL: sorry, too many clients
|
||
already`); raise the flag with `gcloud sql instances patch
|
||
--database-flags=…`, remembering the list **replaces all flags**, so always
|
||
re-include `cloudsql.iam_authentication=on`. Going far beyond ~2× vCPUs in
|
||
*active* connections buys no throughput either — backends are OS processes,
|
||
and excess active ones just context-switch. Sweep around the formula's
|
||
number rather than maximizing.
|
||
|
||
## Proxy sidecar resources
|
||
|
||
The proxy imposes no connection limit and adds
|
||
sub-millisecond latency, but it encrypts all database traffic, so its CPU
|
||
use scales with throughput. The patch
|
||
(`manifests/ate-install/cloudsql/proxy-sidecar-patch.yaml`) requests `100m` — sized
|
||
for control-plane traffic. For sustained thousands of ops/s, raise the
|
||
sidecar's CPU request so node pressure cannot throttle it into becoming the
|
||
bottleneck. Connection *churn* has a separate ceiling: IAM database logins
|
||
are quota'd at 12,000/min per instance — irrelevant for steady pools, but a
|
||
simultaneous reconnect storm across very many replicas can brush it.
|
||
|
||
## Managed Connection Pooling
|
||
|
||
[Managed Connection Pooling](https://docs.cloud.google.com/sql/docs/postgres/managed-connection-pooling)
|
||
(Enterprise Plus only) is a server-side pooler
|
||
(`gcloud sql instances patch <instance> --enable-connection-pooling`) that
|
||
multiplexes up to `max_client_connections` (default 5,000) client
|
||
connections onto at most `max_pool_size` (default 50) backends per
|
||
database+user pair — the fix when very many ateapi replicas would otherwise
|
||
need thousands of real backends. Not usable with atepg's efficient
|
||
`transaction` mode today: the worker-watch path uses `LISTEN`, which
|
||
transaction pooling doesn't support (`session` mode works but forfeits most
|
||
of the multiplexing). If enabled, size `max_pool_size` to the same
|
||
formula's number and reserve ~15 server connections per vCPU in
|
||
`max_connections` for the pooler.
|
||
|
||
## Beyond configuration
|
||
|
||
At billions of rows per table, vacuum duration and index maintenance on
|
||
monolithic tables become the operational limit — partitioning the large
|
||
tables is schema work, not a configuration change.
|