lakebase-autoscaling-guide

Lakebase Autoscaling Guide

Operate Databricks Lakebase Postgres on the Autoscaling tier. Autoscaling is the modern, default Lakebase tier: scale-to-zero, first-class branches, and a hierarchical resource model.

When to apply this skill

• The user asks to create, connect to, branch, scale, or delete a Lakebase database.
• The user mentions databricks postgres, scale-to-zero, compute units / CU, branching a Postgres database on Databricks, or PostgREST.
• The user is troubleshooting Lakebase connectivity, OAuth tokens, or permission denied for schema public.
• A bundled slash command was invoked (/lakebase-create, /lakebase-connect, /lakebase-scale, /lakebase-branch, /lakebase-status, /lakebase-destroy).

If the user explicitly asks about the Provisioned tier (databricks database create-database-instance, CU_1/CU_2/CU_4/CU_8 capacity tiers, the DatabaseInstance resource model), this skill does not apply — say so and stop. Note: databricks psql itself is NOT a Provisioned-only signal — the same command supports both tiers via --provisioned / --autoscaling flags.

Prerequisites checklist

Before running any command, verify:

databricks --version            # must be 0.285.0 or higher
databricks auth profiles        # must show the target profile
psql --version                  # 14+ recommended; needed for shell access
jq --version                    # required by helper scripts

If the CLI is older, instruct the user to upgrade (e.g. brew upgrade databricks). Do not attempt workarounds — Autoscaling commands are gated on the CLI version.

Resource model

Autoscaling Lakebase is hierarchical:

Project          projects/<project-id>
  └── Branch     projects/<project-id>/branches/<branch-id>
       └── Endpoint   projects/<project-id>/branches/<branch-id>/endpoints/<endpoint-id>

• Project: top-level container. Creating a project auto-provisions a production branch and a primary read-write endpoint. The project's default_endpoint_settings (autoscaling bounds + suspend_timeout_duration) become the template for any new branch's auto-created primary endpoint.
• Branch: copy-on-write database snapshot (think git branches). A new branch automatically gets a primary read-write endpoint that inherits the project's default_endpoint_settings. Override afterwards with update-endpoint.
• Endpoint: the compute that serves connections. ENDPOINT_TYPE_READ_WRITE (one per branch) or ENDPOINT_TYPE_READ_ONLY (replicas, multiple allowed). Each endpoint has its own min_cu / max_cu autoscaling bounds (range 0.5-32, with max - min ≤ 16 CU) and a suspend_timeout_duration (idle timer for scale-to-zero — "0s" disables suspension).

Resource IDs: 3-63 chars, lowercase letters/numbers/hyphens, must start with a letter. 2-char IDs are rejected by the API.

API write/read asymmetry: requests use a spec.* wrapper (e.g. --json '{"spec": {"autoscaling_limit_min_cu": 1}}' with mask "spec.autoscaling_limit_min_cu"), but reads return the same fields under status.*. Treat spec as desired state and status as observed state.

60-second quickstart

PROFILE=my-profile
PROJECT=my-app

# 1. Create the project (auto-creates production branch + primary endpoint).
#    create-project ignores display_name in its payload — set it after with update-project.
databricks postgres create-project "$PROJECT" -p "$PROFILE"

# Optional: set a human-readable display name
databricks postgres update-project "projects/$PROJECT" "spec.display_name" \
  --json '{"spec": {"display_name": "My App"}}' \
  -p "$PROFILE"

# 2. Wait for endpoint to reach ACTIVE (usually 60-90s)
until [ "$(databricks postgres list-endpoints "projects/$PROJECT/branches/production" \
  -p "$PROFILE" -o json | jq -r '.[0].status.current_state')" = "ACTIVE" ]; do
  sleep 5
done

# 3. Connect (uses the helper script bundled with this skill)
bash scripts/connect.sh "projects/$PROJECT/branches/production/endpoints/primary" \
  --profile "$PROFILE"

Core operations

Each operation has a dedicated reference under references/ for depth. Load the matching reference when the user asks for more.

Create a project

databricks postgres create-project <project-id> -p <PROFILE>

Auto-creates branches/production and endpoints/primary (defaults: min_cu=1, max_cu=1, suspend_timeout_duration="0s").

create-project does not accept display_name in its payload — the field is silently ignored. To set a human-readable name, follow up with:

databricks postgres update-project projects/<project-id> "spec.display_name" \
  --json '{"spec": {"display_name": "<Display Name>"}}' \
  -p <PROFILE>

Connect

The simplest path is databricks psql with the autoscaling flags — it handles host lookup, token issuance, and identity for you:

databricks psql --project <p> --branch <b> --endpoint <e> -p <PROFILE>
# or pass the full path:
databricks psql projects/<p>/branches/<b>/endpoints/<e> -p <PROFILE>
# pass extra args to the underlying psql after `--`:
databricks psql --project <p> -p <PROFILE> -- -d mydb -c "SELECT 1"

For programmatic access (Python, JDBC, services) you fetch the three pieces yourself:

HOST=$(databricks postgres get-endpoint projects/<p>/branches/<b>/endpoints/<e> \
  -p <PROFILE> -o json | jq -r '.status.hosts.host')
TOKEN=$(databricks postgres generate-database-credential \
  projects/<p>/branches/<b>/endpoints/<e> \
  -p <PROFILE> -o json | jq -r '.token')
EMAIL=$(databricks current-user me -p <PROFILE> -o json | jq -r '.userName')
PGPASSWORD=$TOKEN psql "host=$HOST port=5432 dbname=postgres user=$EMAIL sslmode=require"

OAuth tokens expire after 1 hour — regenerate as needed. The bundled scripts/connect.sh automates the three lookups for shell use; scripts/connection.py does the same for Python (psycopg/psycopg2/SQLAlchemy). See references/connecting.md.

Scale an endpoint

databricks postgres update-endpoint \
  projects/<p>/branches/<b>/endpoints/<endpoint> \
  "spec.autoscaling_limit_min_cu,spec.autoscaling_limit_max_cu" \
  --json '{"spec": {"autoscaling_limit_min_cu": 1.0, "autoscaling_limit_max_cu": 8.0}}' \
  -p <PROFILE>

Bounds: 0.5 ≤ min ≤ max ≤ 32 CU, with max - min ≤ 16 CU (a hard server-side cap). Setting min_cu to 0.5 enables scale-to-zero behavior; setting min_cu >= 1 keeps the endpoint warm. See references/scaling.md for sizing guidance.

Branch

databricks postgres create-branch projects/<p> <new-branch> \
  --json '{"spec": {"source_branch": "projects/<p>/branches/production", "no_expiry": true}}' \
  -p <PROFILE>

The new branch comes with a primary read-write endpoint already attached, sized from the project's default_endpoint_settings. To resize after creation:

databricks postgres update-endpoint projects/<p>/branches/<new-branch>/endpoints/primary \
  "spec.autoscaling_limit_min_cu,spec.autoscaling_limit_max_cu" \
  --json '{"spec": {"autoscaling_limit_min_cu": 0.5, "autoscaling_limit_max_cu": 2.0}}' \
  -p <PROFILE>

suspend_timeout_duration cannot be changed on an existing endpoint via update-endpoint — it's only settable at create-endpoint time, or for new branches' primary endpoints via the project's default_endpoint_settings.

To add a read-only replica, use create-endpoint with endpoint_type: ENDPOINT_TYPE_READ_ONLY and a 3+ char ID. See references/branching.md for protection, deletion, and read-replica patterns.

Inspect status

databricks postgres get-project projects/<p> -p <PROFILE> -o json
databricks postgres list-branches projects/<p> -p <PROFILE> -o json
databricks postgres list-endpoints projects/<p>/branches/<b> -p <PROFILE> -o json

Endpoint states to watch: ACTIVE (ready), STARTING, IDLE (scaled to zero), STOPPED, FAILED.

Destroy

# Non-root branch (cascades to its endpoints; unprotect first if protected)
databricks postgres delete-branch projects/<p>/branches/<b> -p <PROFILE>

# Project (cascades to ALL branches, endpoints, and data — only way to remove the root branch)
databricks postgres delete-project projects/<p> -p <PROFILE>

Always confirm with the user before deleting. Deletion is permanent. Note:

• The default production branch is a root branch and cannot be deleted independently — only via deleting the whole project.
• Read-write endpoints can't be deleted on their own; delete the branch instead. Read-only replicas can.

Common pitfalls

Symptom	Cause	Fix
unknown command postgres	CLI < 0.285.0	Upgrade CLI
Warning: unknown field + Unknown field path in update_mask	JSON body or update-mask missing the spec. prefix	Wrap fields under spec; use spec.<field> in the mask
Field endpoint_id must be at least 3 characters	Endpoint/branch/project ID is 1-2 chars	Use 3+ char IDs
display_name doesn't appear after create	create-project ignores display_name payload	Set with update-project and mask spec.display_name
permission denied for schema public	Working in default postgres database	CREATE DATABASE myapp; then connect to myapp
Auth fails after working earlier	OAuth token expired (1h TTL)	Regenerate via generate-database-credential
Cannot delete read-write endpoint	Read-write endpoints are tied to the branch	Delete the branch instead (cascades)
Endpoint stuck in STARTING	Cold start from scale-to-zero	Wait a few moments (docs say "a few moments to activate"); poll status.current_state
psql: \l errors with daticulocale does not exist	psql 16 client against PG17 server	Use psql 17 client (brew install postgresql@17)
Error: Unknown field path in update_mask: 'spec.suspend_timeout_duration'	This field can't be changed on an existing endpoint	Set at create-endpoint only, or change the project's default_endpoint_settings (parent-mask) and recreate the branch

Full troubleshooting matrix: references/troubleshooting.md.

Reference index

• references/connecting.md — psql, psycopg, SQLAlchemy, .pgpass, token rotation patterns.
• references/branching.md — branch lifecycle, protection, read-replicas, point-in-time semantics.
• references/scaling.md — CU sizing guidance, scale-to-zero tradeoffs, replica scaling.
• references/data-api.md — PostgREST setup, role grants, REST query examples.
• references/unity-catalog.md — registering a Lakebase database in UC, synced tables (Delta → Lakebase).
• references/troubleshooting.md — full error matrix.

Helper scripts

• scripts/connect.sh — given an endpoint path, fetches host/token/email and either prints export commands (--export) or execs psql.
• scripts/connection.py — Python helper that returns a ready-to-use psycopg or SQLAlchemy connection.

Always prefer these scripts over generating the lookup commands inline — they handle token expiry and error cases.

Anti-patterns to refuse

• Hardcoding OAuth tokens in code or .env files (they expire hourly — fetch at runtime).
• Setting max - min > 16 CU on an endpoint (server rejects).
• Setting max_cu = 32 on a dev branch (no upper guard against runaway cost; pair with min ≥ 16 since max - min ≤ 16).
• Creating tables in the default postgres database (restricted public schema; data isn't portable).
• Deleting a project without an explicit user confirmation.
• Treating databricks database create-database-catalog as the UC registration command for Autoscaling — it's the Provisioned-tier path. Autoscaling registers via REST POST /api/2.0/postgres/catalogs or the Catalog Explorer UI; see references/unity-catalog.md.