Avoid table-scanning users at startup (#8271)

This takes about 10 seconds in the best case; often more.
pull/8290/head
Richard van der Hoff 2020-09-07 16:48:52 +01:00 committed by GitHub
parent a55e2707d7
commit ef2804d27c
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2 changed files with 15 additions and 11 deletions

1
changelog.d/8271.bugfix Normal file
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@ -0,0 +1 @@
Fix slow start times for large servers by removing a table scan of the `users` table from startup code.

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@ -29,6 +29,7 @@ from synapse.storage.util.id_generators import (
MultiWriterIdGenerator,
StreamIdGenerator,
)
from synapse.types import get_domain_from_id
from synapse.util.caches.stream_change_cache import StreamChangeCache
from .account_data import AccountDataStore
@ -591,22 +592,24 @@ def check_database_before_upgrade(cur, database_engine, config: HomeServerConfig
"""Called before upgrading an existing database to check that it is broadly sane
compared with the configuration.
"""
logger.info("Running sanity-checks on database...")
domain = config.server_name
logger.info("Checking database for consistency with configuration...")
sql = database_engine.convert_param_style(
"SELECT COUNT(*) FROM users WHERE name NOT LIKE ?"
)
pat = "%:" + domain
cur.execute(sql, (pat,))
num_not_matching = cur.fetchall()[0][0]
if num_not_matching == 0:
# if there are any users in the database, check that the username matches our
# configured server name.
cur.execute("SELECT name FROM users LIMIT 1")
rows = cur.fetchall()
if not rows:
return
user_domain = get_domain_from_id(rows[0][0])
if user_domain == config.server_name:
return
raise Exception(
"Found users in database not native to %s!\n"
"You cannot changed a synapse server_name after it's been configured"
% (domain,)
"You cannot change a synapse server_name after it's been configured"
% (config.server_name,)
)