Need a way to remove 'bad' connections from a connection pool

Looking at the pool code, there is a way to discard the connection: use putconn(cnn, close=True), but it is not documented: I will fix the documentation.

However I think the pool should be more careful on the connection it receives: I will fix it to detect broken/intrans/error connections and deal with them.

Ah, thanks for that information.

Does this look like the right thing to do in order to get a connection from the pool? Sorry if this sounds like a support request, but it will be a while until updated versions of psycopg2 filter down to end-users, so some example code might be helpful:

conn = None
while conn is None:
    c = pool.getconn()
    try:
        c.cursor().execute('SELECT 0')
    except:
        pool.putconn(c,close=True)
    else:
        c.rollback()
        conn = c
try:
    f(conn)
except:
    conn.rollback()
    raise
finally:
    pool.putconn(conn)

Yes, what you propose is a robust way to get a connection from the pool guarding from a server disconnection. I don't want to add a probe query into the pool code: the code will have a guard on putconn() discarding a broken connection but the f() could still receive a connection we don't know if broken. If your f() can't cope with it, you'd better keep your probing pattern even with future psycopg releases.