I’m using Peewee as ORM and connect to a Postgres database (psycopg2) using the Playhouse extension db_url.connect. My URL is a vanilla postgresql://username:pass@host:port/dbname?options=... so not using pooling or anything advanced at the moment.
Some times when I call connect it hangs for a long time and doesn’t come back. So I appended to my database URL the parameter &connect_timeout=3 meaning to try for at most 3 seconds and fail-fast with a timeout rather than hanging forever. However, I am not sure whether this argument is supported by Peewee/Playhouse/Psycopg2 … can anyone confirm?
Furthermore, where can I find all the URL parameters supported by Peewee/Playhouse/Psycopg2?
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Answer
The psycopg2 doc links in turn to the libpq list of supported parameters:
https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS
connect_timeout is supported by both peewee and psycopg2:
>>> from playhouse.db_url import *
>>> db = connect('postgresql://../peewee_test?connect_timeout=3')
>>> conn = db.connection()
>>> conn.get_dsn_parameters()
{'user': 'postgres',
'passfile': '...',
'channel_binding': 'prefer',
'connect_timeout': '3', # Our connect timeout
'dbname': 'peewee_test',
'host': 'localhost',
'port': '5432',
...}
Peewee passes the parameters, including arbitrary ones like connect_timeout, back to the constructor of the DB-API Connection class.