From c165c1233b8ef244fadca97c7d465fdcf473d077 Mon Sep 17 00:00:00 2001 From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com> Date: Fri, 20 Mar 2020 16:24:22 +0100 Subject: [PATCH] Improve database configuration docs (#6988) Attempts to clarify the sample config for databases, and add some stuff about tcp keepalives to `postgres.md`. --- changelog.d/6988.doc | 1 + docs/postgres.md | 42 ++++++++++++---- docs/sample_config.yaml | 43 ++++++++++++++-- synapse/config/_base.py | 2 - synapse/config/database.py | 93 ++++++++++++++++++++++------------- tests/config/test_database.py | 22 +-------- 6 files changed, 132 insertions(+), 71 deletions(-) create mode 100644 changelog.d/6988.doc diff --git a/changelog.d/6988.doc b/changelog.d/6988.doc new file mode 100644 index 0000000000..b6f71bb966 --- /dev/null +++ b/changelog.d/6988.doc @@ -0,0 +1 @@ +Improve the documentation for database configuration. diff --git a/docs/postgres.md b/docs/postgres.md index e0793ecee8..16a630c3d1 100644 --- a/docs/postgres.md +++ b/docs/postgres.md @@ -105,19 +105,41 @@ of free memory the database host has available. When you are ready to start using PostgreSQL, edit the `database` section in your config file to match the following lines: - database: - name: psycopg2 - args: - user: - password: - database: - host: - cp_min: 5 - cp_max: 10 +```yaml +database: + name: psycopg2 + args: + user: + password: + database: + host: + cp_min: 5 + cp_max: 10 +``` All key, values in `args` are passed to the `psycopg2.connect(..)` function, except keys beginning with `cp_`, which are consumed by the -twisted adbapi connection pool. +twisted adbapi connection pool. See the [libpq +documentation](https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS) +for a list of options which can be passed. + +You should consider tuning the `args.keepalives_*` options if there is any danger of +the connection between your homeserver and database dropping, otherwise Synapse +may block for an extended period while it waits for a response from the +database server. Example values might be: + +```yaml +# seconds of inactivity after which TCP should send a keepalive message to the server +keepalives_idle: 10 + +# the number of seconds after which a TCP keepalive message that is not +# acknowledged by the server should be retransmitted +keepalives_interval: 10 + +# the number of TCP keepalives that can be lost before the client's connection +# to the server is considered dead +keepalives_count: 3 +``` ## Porting from SQLite diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml index 2ff0dd05a2..276e43b732 100644 --- a/docs/sample_config.yaml +++ b/docs/sample_config.yaml @@ -578,13 +578,46 @@ acme: ## Database ## +# The 'database' setting defines the database that synapse uses to store all of +# its data. +# +# 'name' gives the database engine to use: either 'sqlite3' (for SQLite) or +# 'psycopg2' (for PostgreSQL). +# +# 'args' gives options which are passed through to the database engine, +# except for options starting 'cp_', which are used to configure the Twisted +# connection pool. For a reference to valid arguments, see: +# * for sqlite: https://docs.python.org/3/library/sqlite3.html#sqlite3.connect +# * for postgres: https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS +# * for the connection pool: https://twistedmatrix.com/documents/current/api/twisted.enterprise.adbapi.ConnectionPool.html#__init__ +# +# +# Example SQLite configuration: +# +#database: +# name: sqlite3 +# args: +# database: /path/to/homeserver.db +# +# +# Example Postgres configuration: +# +#database: +# name: psycopg2 +# args: +# user: synapse +# password: secretpassword +# database: synapse +# host: localhost +# cp_min: 5 +# cp_max: 10 +# +# For more information on using Synapse with Postgres, see `docs/postgres.md`. +# database: - # The database engine name - name: "sqlite3" - # Arguments to pass to the engine + name: sqlite3 args: - # Path to the database - database: "DATADIR/homeserver.db" + database: DATADIR/homeserver.db # Number of events to cache in memory. # diff --git a/synapse/config/_base.py b/synapse/config/_base.py index ba846042c4..efe2af5504 100644 --- a/synapse/config/_base.py +++ b/synapse/config/_base.py @@ -294,7 +294,6 @@ class RootConfig(object): report_stats=None, open_private_ports=False, listeners=None, - database_conf=None, tls_certificate_path=None, tls_private_key_path=None, acme_domain=None, @@ -367,7 +366,6 @@ class RootConfig(object): report_stats=report_stats, open_private_ports=open_private_ports, listeners=listeners, - database_conf=database_conf, tls_certificate_path=tls_certificate_path, tls_private_key_path=tls_private_key_path, acme_domain=acme_domain, diff --git a/synapse/config/database.py b/synapse/config/database.py index 219b32f670..b8ab2f86ac 100644 --- a/synapse/config/database.py +++ b/synapse/config/database.py @@ -1,5 +1,6 @@ # -*- coding: utf-8 -*- # Copyright 2014-2016 OpenMarket Ltd +# Copyright 2020 The Matrix.org Foundation C.I.C. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. @@ -14,14 +15,60 @@ # limitations under the License. import logging import os -from textwrap import indent - -import yaml from synapse.config._base import Config, ConfigError logger = logging.getLogger(__name__) +DEFAULT_CONFIG = """\ +## Database ## + +# The 'database' setting defines the database that synapse uses to store all of +# its data. +# +# 'name' gives the database engine to use: either 'sqlite3' (for SQLite) or +# 'psycopg2' (for PostgreSQL). +# +# 'args' gives options which are passed through to the database engine, +# except for options starting 'cp_', which are used to configure the Twisted +# connection pool. For a reference to valid arguments, see: +# * for sqlite: https://docs.python.org/3/library/sqlite3.html#sqlite3.connect +# * for postgres: https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS +# * for the connection pool: https://twistedmatrix.com/documents/current/api/twisted.enterprise.adbapi.ConnectionPool.html#__init__ +# +# +# Example SQLite configuration: +# +#database: +# name: sqlite3 +# args: +# database: /path/to/homeserver.db +# +# +# Example Postgres configuration: +# +#database: +# name: psycopg2 +# args: +# user: synapse +# password: secretpassword +# database: synapse +# host: localhost +# cp_min: 5 +# cp_max: 10 +# +# For more information on using Synapse with Postgres, see `docs/postgres.md`. +# +database: + name: sqlite3 + args: + database: %(database_path)s + +# Number of events to cache in memory. +# +#event_cache_size: 10K +""" + class DatabaseConnectionConfig: """Contains the connection config for a particular database. @@ -36,10 +83,12 @@ class DatabaseConnectionConfig: """ def __init__(self, name: str, db_config: dict): - if db_config["name"] not in ("sqlite3", "psycopg2"): - raise ConfigError("Unsupported database type %r" % (db_config["name"],)) + db_engine = db_config.get("name", "sqlite3") - if db_config["name"] == "sqlite3": + if db_engine not in ("sqlite3", "psycopg2"): + raise ConfigError("Unsupported database type %r" % (db_engine,)) + + if db_engine == "sqlite3": db_config.setdefault("args", {}).update( {"cp_min": 1, "cp_max": 1, "check_same_thread": False} ) @@ -97,34 +146,10 @@ class DatabaseConfig(Config): self.set_databasepath(config.get("database_path")) - def generate_config_section(self, data_dir_path, database_conf, **kwargs): - if not database_conf: - database_path = os.path.join(data_dir_path, "homeserver.db") - database_conf = ( - """# The database engine name - name: "sqlite3" - # Arguments to pass to the engine - args: - # Path to the database - database: "%(database_path)s" - """ - % locals() - ) - else: - database_conf = indent(yaml.dump(database_conf), " " * 10).lstrip() - - return ( - """\ - ## Database ## - - database: - %(database_conf)s - # Number of events to cache in memory. - # - #event_cache_size: 10K - """ - % locals() - ) + def generate_config_section(self, data_dir_path, **kwargs): + return DEFAULT_CONFIG % { + "database_path": os.path.join(data_dir_path, "homeserver.db") + } def read_arguments(self, args): self.set_databasepath(args.database_path) diff --git a/tests/config/test_database.py b/tests/config/test_database.py index 151d3006ac..f675bde68e 100644 --- a/tests/config/test_database.py +++ b/tests/config/test_database.py @@ -21,9 +21,9 @@ from tests import unittest class DatabaseConfigTestCase(unittest.TestCase): - def test_database_configured_correctly_no_database_conf_param(self): + def test_database_configured_correctly(self): conf = yaml.safe_load( - DatabaseConfig().generate_config_section("/data_dir_path", None) + DatabaseConfig().generate_config_section(data_dir_path="/data_dir_path") ) expected_database_conf = { @@ -32,21 +32,3 @@ class DatabaseConfigTestCase(unittest.TestCase): } self.assertEqual(conf["database"], expected_database_conf) - - def test_database_configured_correctly_database_conf_param(self): - - database_conf = { - "name": "my super fast datastore", - "args": { - "user": "matrix", - "password": "synapse_database_password", - "host": "synapse_database_host", - "database": "matrix", - }, - } - - conf = yaml.safe_load( - DatabaseConfig().generate_config_section("/data_dir_path", database_conf) - ) - - self.assertEqual(conf["database"], database_conf)