我正在运行一个 Multi-Tenancy 网站,我希望减少为每个请求创建 PostgreSQL 连接的开销。 Django 的 CONN_MAX_AGE 允许这样做,但代价是创建大量与 PostgreSQL 的开放空闲连接(8 个工作线程 * 20 个线程 = 160 个连接)。每个连接 10MB,这会消耗大量内存。
主要目的是减少连接时间开销。 因此我的问题是:
- 对于此类解决方案,我应该使用哪种设置? (PgBouncer?)
- 我可以在 Django 中使用“事务”池模式吗?
- 我使用类似的东西会更好吗:https://github.com/kennethreitz/django-postgrespool而不是 Django 的池化?
Django 1.6 设置:
DATABASES['default'] = {
'ENGINE': 'django.db.backends.postgresql_psycopg2',
....
'PORT': '6432'
'OPTIONS': {'autocommit': True,},
'CONN_MAX_AGE': 300,
}
ATOMIC_REQUESTS = False # default
Postgres:
max_connections = 100
PgBouncer:
pool_mode = session # Can this be transaction?
max_client_conn = 400 # Should this match postgres max_connections?
default_pool_size = 20
reserve_pool_size = 5
最佳答案
这是我使用过的设置。
pgbouncer 与 Gunicorn、celery 等在同一台机器上运行
pgbouncer.ini:
[databases]
<dbname> = host=<dbhost> port=<dbport> dbname=<dbname>
[pgbouncer]
: your app will need filesystem permissions to this unix socket
unix_socket_dir = /var/run/postgresql
; you'll need to configure this file with username/password pairs you plan on
; connecting with.
auth_file = /etc/pgbouncer/userlist.txt
; "session" resulted in atrocious performance for us. I think
; "statement" prevents transactions from working.
pool_mode = transaction
; you'll probably want to change default_pool_size. take the max number of
; connections for your postgresql server, and divide that by the number of
; pgbouncer instances that will be conecting to it, then subtract a few
; connections so you can still connect to PG as an admin if something goes wrong.
; you may then need to adjust min_pool_size and reserve_pool_size accordingly.
default_pool_size = 50
min_pool_size = 10
reserve_pool_size = 10
reserve_pool_timeout = 2
; I was using gunicorn + eventlet, which is why this is so high. It
; needs to be high enough to accommodate all the persistent connections we're
; going to allow from Django & other apps.
max_client_conn = 1000
...
/etc/pgbouncer/userlist.txt:
"<dbuser>" "<dbpassword>"
Django 设置.py:
...
DATABASES = {
'default': {
'ENGINE': 'django.contrib.gis.db.backends.postgresql_psycopg2',
'NAME': '<dbname>',
'USER': '<dbuser>',
'PASSWORD': '<dbpassword>',
'HOST': '/var/run/postgresql',
'PORT': '',
'CONN_MAX_AGE': None, # Set to None for persistent connections
}
}
...
如果我没记错的话,你基本上可以与 pgbouncer 建立任意数量的“持久”连接,因为当 Django 处理完服务器连接后,pgbouncer 会将服务器连接释放回池中(只要你使用 transaction
或 pool_mode
的语句
)。当 Django 尝试重用其持久连接时,pgbouncer 负责等待与 Postgres 的可用连接。
关于django - pgbouncer 与 Django 的 CONN_MAX_AGE 的理想设置,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/27418264/