b58e429c1c
The DB is at max_connections=100 with ~9 services each holding persistent pools (several as the postgres superuser, idle for hours), so peaks hit "too many connections". PgBouncer multiplexes many client connections onto a small fixed set of backends, bounding DB connections regardless of how many app pools exist. Adds (stack-wide infra, parked in this repo for now — see README scope note): - pgbouncer.ini: transaction pooling, auth_query pass-through, bounded pool sizes - auth_setup.sql: pgbouncer_auth role + SECURITY DEFINER pgbouncer.user_lookup() so per-app passwords aren't hand-maintained - docker-compose.yml: the service (join the existing DB network) - userlist.txt.example + .gitignore: keep the auth verifier out of git - README.md: deploy steps, incremental cutover (superuser apps first), and the transaction-pooling caveats — including the MCP-specific note (rely on role-level GUCs; simplest to leave the minor MCP direct and pool the heavy superuser apps) Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
64 lines
3.5 KiB
INI
64 lines
3.5 KiB
INI
; pgbouncer.ini — transaction-pooling front for timescale_db (tracksolid_db).
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; ─────────────────────────────────────────────────────────────────────────────
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; Purpose: the DB runs at max_connections=100 and ~9 stack services each hold a
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; persistent pool (several as the postgres superuser, idle for hours), so peaks hit
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; "too many connections". PgBouncer multiplexes MANY client connections onto a SMALL
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; set of real backend connections, so the DB connection count stays bounded no matter
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; how many app pools exist.
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;
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; Auth uses auth_query (NOT a hand-maintained userlist of every app): PgBouncer logs
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; in as `pgbouncer_auth` and looks each user's verifier up via pgbouncer.user_lookup()
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; — see auth_setup.sql. Only the pgbouncer_auth verifier lives in userlist.txt.
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[databases]
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; Apps point their DSN host at pgbouncer:6432 with the SAME dbname/user/password.
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; `host` here is the real DB (the timescale_db container hostname on the DB network).
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tracksolid_db = host=timescale_db port=5432 dbname=tracksolid_db
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[pgbouncer]
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listen_addr = 0.0.0.0
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listen_port = 6432
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; ── Auth (pass-through via auth_query) ──────────────────────────────────────
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auth_type = scram-sha-256
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auth_file = /etc/pgbouncer/userlist.txt
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auth_user = pgbouncer_auth
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auth_query = SELECT uname, phash FROM pgbouncer.user_lookup($1)
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; ── Pooling ─────────────────────────────────────────────────────────────────
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; transaction mode = a server connection is returned to the pool at COMMIT/ROLLBACK,
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; so a handful of backends serve hundreds of clients. See README for the feature
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; caveats (no session-level prepared statements / SET that persists across txns).
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pool_mode = transaction
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; Total backend connections PgBouncer will ever open to the DB =
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; (number of [databases] entries) × default_pool_size + reserve_pool_size.
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; Keep the SUM across all poolers well under the DB's max_connections (100).
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; With one database and 20 + 5 reserve = 25 backends max — leaving headroom for
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; superuser/admin/background-worker connections that bypass PgBouncer.
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default_pool_size = 20
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min_pool_size = 0
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reserve_pool_size = 5
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reserve_pool_timeout = 3
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; Clients can be plentiful (cheap) — only backends are scarce.
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max_client_conn = 2000
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; Recycle idle/old server connections so none linger for hours.
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server_idle_timeout = 300
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server_lifetime = 3600
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; ── Robustness ──────────────────────────────────────────────────────────────
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; Apps set per-connection GUCs via the `options` startup param (e.g. the analytics
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; MCP sends `-c default_transaction_read_only=on -c statement_timeout=...`). In
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; transaction pooling those can't be honored per-shared-backend, so ignore them and
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; rely on ROLE-level settings (ALTER ROLE ... SET ...) instead. See README.
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ignore_startup_parameters = extra_float_digits,options,search_path
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; Admin/stats console (psql -p 6432 pgbouncer) — restricted to the auth role.
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admin_users = pgbouncer_auth
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stats_users = pgbouncer_auth
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; Quiet by default; flip to 1 temporarily when debugging.
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log_connections = 0
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log_disconnections = 0
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