add recommended SQLite db connection settings to avoid single-writer lock contention

This commit is contained in:
Nick Sweeting 2024-09-11 16:50:44 -07:00
parent ee1b881d43
commit eae11cba19
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@ -222,21 +222,42 @@ DATABASES = {
"default": {
"ENGINE": "django.db.backends.sqlite3",
"NAME": DATABASE_NAME,
"OPTIONS": {
"timeout": 60,
"check_same_thread": False,
},
"TIME_ZONE": CONFIG.TIMEZONE,
"OPTIONS": {
# https://gcollazo.com/optimal-sqlite-settings-for-django/
"timeout": 5,
"check_same_thread": False,
"transaction_mode": "IMMEDIATE",
"init_command": (
"PRAGMA foreign_keys=ON;"
"PRAGMA journal_mode = WAL;"
"PRAGMA synchronous = NORMAL;"
"PRAGMA temp_store = MEMORY;"
"PRAGMA mmap_size = 134217728;"
"PRAGMA journal_size_limit = 67108864;"
"PRAGMA cache_size = 2000;"
),
},
# DB setup is sometimes modified at runtime by setup_django() in config.py
},
"queue": {
"ENGINE": "django.db.backends.sqlite3",
"NAME": QUEUE_DATABASE_NAME,
"OPTIONS": {
"timeout": 60,
"check_same_thread": False,
},
"TIME_ZONE": CONFIG.TIMEZONE,
"OPTIONS": {
"timeout": 5,
"check_same_thread": False,
"transaction_mode": "IMMEDIATE",
"init_command": (
"PRAGMA foreign_keys=ON;"
"PRAGMA journal_mode = WAL;"
"PRAGMA synchronous = NORMAL;"
"PRAGMA temp_store = MEMORY;"
"PRAGMA mmap_size = 134217728;"
"PRAGMA journal_size_limit = 67108864;"
"PRAGMA cache_size = 2000;"
),
},
},
# 'cache': {
# 'ENGINE': 'django.db.backends.sqlite3',
@ -286,7 +307,13 @@ DJANGO_HUEY = {
}
class HueyDBRouter:
"""A router to store all the Huey Monitor models in the queue.sqlite3 database."""
"""
A router to store all the Huey result k:v / Huey Monitor models in the queue.sqlite3 database.
We keep the databases separate because the queue database receives many more reads/writes per second
and we want to avoid single-write lock contention with the main database. Also all the in-progress task
data is ephemeral/not-important-long-term. This makes it easier to for the user to clear non-critical
temp data by just deleting queue.sqlite3 and leaving index.sqlite3.
"""
route_app_labels = {"huey_monitor", "django_huey", "djhuey"}